diff --git a/documentation/webdocs/markdowndocs/administrator-ch.md b/documentation/webdocs/markdowndocs/administrator-ch.md
index 44b3ad4671..79388a2edb 100644
--- a/documentation/webdocs/markdowndocs/administrator-ch.md
+++ b/documentation/webdocs/markdowndocs/administrator-ch.md
@@ -87,6 +87,7 @@ TDengine系统后台服务由taosd提供，可以在配置文件taos.cfg里修
 - httpPort: RESTful服务使用的端口号，所有的HTTP请求（TCP）都需要向该接口发起查询/写入请求。
 - dataDir: 数据文件目录，所有的数据文件都将写入该目录。默认值：/var/lib/taos。
 - logDir：日志文件目录，客户端和服务器的运行日志文件将写入该目录。默认值：/var/log/taos。
+- tempDir：临时文件目录，客户端和服务器的临时文件（主要是查询时用于保存中间结果的问题）将写入该目录。 默认值：Linux下为 /tmp/，Windows下为环境变量 tmp 或 temp 指向的目录。
 - arbitrator：系统中裁决器的end point, 缺省值为空。
 - role：dnode的可选角色。0-any; 既可作为mnode，也可分配vnode；1-mgmt;只能作为mnode，不能分配vnode；2-dnode;不能作为mnode，只能分配vnode
 - debugFlag：运行日志开关。131（输出错误和警告日志），135（ 输出错误、警告和调试日志），143（ 输出错误、警告、调试和跟踪日志）。默认值：131或135（不同模块有不同的默认值）。
diff --git a/documentation20/webdocs/markdowndocs/connector-ch.md b/documentation20/webdocs/markdowndocs/connector-ch.md
index 0e29b32487..c5a955f43f 100644
--- a/documentation20/webdocs/markdowndocs/connector-ch.md
+++ b/documentation20/webdocs/markdowndocs/connector-ch.md
@@ -616,6 +616,43 @@ HTTP请求URL采用`sqlutc`时，返回结果集的时间戳将采用UTC时间
 - httpEnableCompress: 是否支持压缩，默认不支持，目前TDengine仅支持gzip压缩格式
 - httpDebugFlag: 日志开关，131：仅错误和报警信息，135：调试信息，143：非常详细的调试信息，默认131
 
+## CSharp Connector
+
+在Windows系统上，C#应用程序可以使用TDengine的原生C接口来执行所有数据库操作，后续版本将提供ORM（dapper）框架驱动。
+
+#### 安装TDengine客户端
+
+C#连接器需要使用`libtaos.so`和`taos.h`。因此，在使用C#连接器之前，需在程序运行的Windows环境安装TDengine的Windows客户端，以便获得相关驱动文件。
+
+安装完成后，在文件夹`C:/TDengine/examples/C#`中，将会看到两个文件
+
+- TDengineDriver.cs 调用taos.dll文件的Native C方法
+- TDengineTest.cs 参考程序示例
+
+在文件夹`C:\Windows\System32`，将会看到`taos.dll`文件
+
+#### 使用方法
+
+- 将C#接口文件TDengineDriver.cs加入到应用程序所在.NET项目中
+- 参考TDengineTest.cs来定义数据库连接参数，及执行数据插入、查询等操作的方法
+- 因为C#接口需要用到`taos.dll`文件，用户可以将`taos.dll`文件加入.NET解决方案中
+
+#### 注意事项
+
+- `taos.dll`文件使用x64平台编译，所以.NET项目在生成.exe文件时，“解决方案”/“项目”的“平台”请均选择“x64”。
+- 此.NET接口目前已经在Visual Studio 2013/2015/2017中验证过，其它VS版本尚待验证。
+
+#### 第三方驱动
+
+Maikebing.Data.Taos是一个TDengine的ADO.Net提供器，支持linux，windows。该开发包由热心贡献者`麦壳饼@@maikebing`提供，具体请参考
+
+```
+//接口下载
+https://github.com/maikebing/Maikebing.EntityFrameworkCore.Taos   
+//用法说明    
+https://www.taosdata.com/blog/2020/11/02/1901.html                    
+```
+
 
 ## Go Connector
 
diff --git a/packaging/cfg/taos.cfg b/packaging/cfg/taos.cfg
index 974b2b05c1..ca88bca3c8 100644
--- a/packaging/cfg/taos.cfg
+++ b/packaging/cfg/taos.cfg
@@ -20,6 +20,9 @@
 # data file's directory
 # dataDir                   /var/lib/taos
 
+# temporary file's directory
+# tempDir                   /tmp/
+
 # the arbitrator's fully qualified domain name (FQDN) for TDengine system, for cluster only   
 # arbitrator                arbitrator_hostname:6042     
 
@@ -256,3 +259,5 @@
 # maximum display width of binary and nchar fields in the shell. The parts exceeding this limit will be hidden
 # maxBinaryDisplayWidth 30
 
+# enable/disable telemetry reporting
+# telemetryReporting    1
\ No newline at end of file
diff --git a/packaging/rpm/tdengine.spec b/packaging/rpm/tdengine.spec
index e49baeffc7..54c3c9b279 100644
--- a/packaging/rpm/tdengine.spec
+++ b/packaging/rpm/tdengine.spec
@@ -2,7 +2,7 @@
 %define cfg_install_dir  /etc/taos
 %define __strip /bin/true
 
-Name:		TDengine
+Name:		tdengine
 Version:	%{_version}
 Release:	3%{?dist}
 Summary:	tdengine from taosdata
diff --git a/src/balance/src/balance.c b/src/balance/src/balance.c
index 0e9bb85b25..4c687cb134 100644
--- a/src/balance/src/balance.c
+++ b/src/balance/src/balance.c
@@ -490,7 +490,7 @@ static bool balanceMontiorDropping() {
 
     if (pDnode->status == TAOS_DN_STATUS_OFFLINE) {
       if (pDnode->lastAccess + tsOfflineThreshold > tsAccessSquence) continue;
-      if (strcmp(pDnode->dnodeEp, dnodeGetMnodeMasterEp()) == 0) continue; 
+      if (dnodeIsMasterEp(pDnode->dnodeEp)) continue; 
       if (mnodeGetDnodesNum() <= 1) continue;
 
       mLInfo("dnode:%d, set to removing state for it offline:%d seconds", pDnode->dnodeId,
diff --git a/src/client/inc/tscUtil.h b/src/client/inc/tscUtil.h
index 39299d3308..2f918e1e93 100644
--- a/src/client/inc/tscUtil.h
+++ b/src/client/inc/tscUtil.h
@@ -87,8 +87,8 @@ typedef struct SJoinSupporter {
 } SJoinSupporter;
 
 typedef struct SVgroupTableInfo {
-  SCMVgroupInfo vgInfo;
-  SArray*       itemList;   //SArray<STableIdInfo>
+  SVgroupInfo vgInfo;
+  SArray*     itemList;   //SArray<STableIdInfo>
 } SVgroupTableInfo;
 
 static FORCE_INLINE SQueryInfo* tscGetQueryInfoDetail(SSqlCmd* pCmd, int32_t subClauseIndex) {
@@ -238,7 +238,7 @@ void tscDoQuery(SSqlObj* pSql);
 
 SVgroupsInfo* tscVgroupInfoClone(SVgroupsInfo *pInfo);
 void* tscVgroupInfoClear(SVgroupsInfo *pInfo);
-void tscSCMVgroupInfoCopy(SCMVgroupInfo* dst, const SCMVgroupInfo* src);
+void tscSVgroupInfoCopy(SVgroupInfo* dst, const SVgroupInfo* src);
 /**
  * The create object function must be successful expect for the out of memory issue.
  *
diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index bbd029d675..0e5a206c27 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -90,12 +90,12 @@ typedef struct STableComInfo {
   int32_t rowSize;
 } STableComInfo;
 
-typedef struct SCMCorVgroupInfo {
-  int32_t    version;
-  int8_t     inUse;
-  int8_t     numOfEps;
-  SEpAddr1   epAddr[TSDB_MAX_REPLICA];
-} SCMCorVgroupInfo;
+typedef struct SCorVgroupInfo {
+  int32_t  version;
+  int8_t   inUse;
+  int8_t   numOfEps;
+  SEpAddr1 epAddr[TSDB_MAX_REPLICA];
+} SCorVgroupInfo;
 
 typedef struct STableMeta {
   STableComInfo  tableInfo;
@@ -103,8 +103,8 @@ typedef struct STableMeta {
   int16_t        sversion;
   int16_t        tversion;
   char           sTableId[TSDB_TABLE_FNAME_LEN];
-  SCMVgroupInfo  vgroupInfo;
-  SCMCorVgroupInfo  corVgroupInfo;
+  SVgroupInfo    vgroupInfo;
+  SCorVgroupInfo corVgroupInfo;
   STableId       id;
   SSchema        schema[];  // if the table is TSDB_CHILD_TABLE, schema is acquired by super table meta info
 } STableMeta;
diff --git a/src/client/src/tscParseInsert.c b/src/client/src/tscParseInsert.c
index ac34d26d2f..5e65126ef6 100644
--- a/src/client/src/tscParseInsert.c
+++ b/src/client/src/tscParseInsert.c
@@ -702,7 +702,7 @@ static int32_t doParseInsertStatement(SSqlObj *pSql, void *pTableList, char **st
   }
 
   int32_t code = TSDB_CODE_TSC_INVALID_SQL;
-  char *  tmpTokenBuf = calloc(1, 4096);  // used for deleting Escape character: \\, \', \"
+  char *  tmpTokenBuf = calloc(1, 16*1024);  // used for deleting Escape character: \\, \', \"
   if (NULL == tmpTokenBuf) {
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
diff --git a/src/client/src/tscProfile.c b/src/client/src/tscProfile.c
index eb6843b0e4..acc5acd786 100644
--- a/src/client/src/tscProfile.c
+++ b/src/client/src/tscProfile.c
@@ -222,7 +222,7 @@ void tscKillStream(STscObj *pObj, uint32_t killId) {
 }
 
 int tscBuildQueryStreamDesc(void *pMsg, STscObj *pObj) {
-  SCMHeartBeatMsg *pHeartbeat = pMsg;
+  SHeartBeatMsg *pHeartbeat = pMsg;
   int allocedQueriesNum = pHeartbeat->numOfQueries;
   int allocedStreamsNum = pHeartbeat->numOfStreams;
   
@@ -277,7 +277,7 @@ int tscBuildQueryStreamDesc(void *pMsg, STscObj *pObj) {
   }
 
   int32_t msgLen = pHeartbeat->numOfQueries * sizeof(SQueryDesc) + pHeartbeat->numOfStreams * sizeof(SStreamDesc) +
-                   sizeof(SCMHeartBeatMsg);
+                   sizeof(SHeartBeatMsg);
   pHeartbeat->connId = htonl(pObj->connId);
   pHeartbeat->numOfQueries = htonl(pHeartbeat->numOfQueries);
   pHeartbeat->numOfStreams = htonl(pHeartbeat->numOfStreams);
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index f537db4e3d..7dfd561960 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -114,7 +114,7 @@ static int32_t optrToString(tSQLExpr* pExpr, char** exprString);
 static int32_t getTableIndexImpl(SStrToken* pTableToken, SQueryInfo* pQueryInfo, SColumnIndex* pIndex);
 static int32_t doFunctionsCompatibleCheck(SSqlCmd* pCmd, SQueryInfo* pQueryInfo);
 static int32_t doLocalQueryProcess(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql);
-static int32_t tscCheckCreateDbParams(SSqlCmd* pCmd, SCMCreateDbMsg* pCreate);
+static int32_t tscCheckCreateDbParams(SSqlCmd* pCmd, SCreateDbMsg* pCreate);
 
 static SColumnList getColumnList(int32_t num, int16_t tableIndex, int32_t columnIndex);
 
@@ -417,7 +417,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
       char* pMsg = pCmd->payload;
 
-      SCMCfgDnodeMsg* pCfg = (SCMCfgDnodeMsg*)pMsg;
+      SCfgDnodeMsg* pCfg = (SCfgDnodeMsg*)pMsg;
       pDCL->a[0].n = strdequote(pDCL->a[0].z);
       
       strncpy(pCfg->ep, pDCL->a[0].z, pDCL->a[0].n);
@@ -619,11 +619,15 @@ static bool isTopBottomQuery(SQueryInfo* pQueryInfo) {
 int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql) {
   const char* msg1 = "invalid query expression";
   const char* msg2 = "interval cannot be less than 10 ms";
+  const char* msg3 = "sliding cannot be used without interval";
 
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   STableComInfo tinfo = tscGetTableInfo(pTableMetaInfo->pTableMeta);
   
   if (pQuerySql->interval.type == 0 || pQuerySql->interval.n == 0) {
+    if (pQuerySql->sliding.n > 0) {
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
+    }
     return TSDB_CODE_SUCCESS;
   }
 
@@ -5185,7 +5189,7 @@ int32_t parseLimitClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t clauseIn
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t setKeepOption(SSqlCmd* pCmd, SCMCreateDbMsg* pMsg, SCreateDBInfo* pCreateDb) {
+static int32_t setKeepOption(SSqlCmd* pCmd, SCreateDbMsg* pMsg, SCreateDBInfo* pCreateDb) {
   const char* msg = "invalid number of options";
 
   pMsg->daysToKeep = htonl(-1);
@@ -5216,7 +5220,7 @@ static int32_t setKeepOption(SSqlCmd* pCmd, SCMCreateDbMsg* pMsg, SCreateDBInfo*
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t setTimePrecision(SSqlCmd* pCmd, SCMCreateDbMsg* pMsg, SCreateDBInfo* pCreateDbInfo) {
+static int32_t setTimePrecision(SSqlCmd* pCmd, SCreateDbMsg* pMsg, SCreateDBInfo* pCreateDbInfo) {
   const char* msg = "invalid time precision";
 
   pMsg->precision = TSDB_TIME_PRECISION_MILLI;  // millisecond by default
@@ -5240,7 +5244,7 @@ static int32_t setTimePrecision(SSqlCmd* pCmd, SCMCreateDbMsg* pMsg, SCreateDBIn
   return TSDB_CODE_SUCCESS;
 }
 
-static void setCreateDBOption(SCMCreateDbMsg* pMsg, SCreateDBInfo* pCreateDb) {
+static void setCreateDBOption(SCreateDbMsg* pMsg, SCreateDBInfo* pCreateDb) {
   pMsg->maxTables = htonl(-1);  // max tables can not be set anymore
   pMsg->cacheBlockSize = htonl(pCreateDb->cacheBlockSize);
   pMsg->totalBlocks = htonl(pCreateDb->numOfBlocks);
@@ -5258,7 +5262,7 @@ static void setCreateDBOption(SCMCreateDbMsg* pMsg, SCreateDBInfo* pCreateDb) {
 }
 
 int32_t parseCreateDBOptions(SSqlCmd* pCmd, SCreateDBInfo* pCreateDbSql) {
-  SCMCreateDbMsg* pMsg = (SCMCreateDbMsg*)(pCmd->payload);
+  SCreateDbMsg* pMsg = (SCreateDbMsg *)(pCmd->payload);
   setCreateDBOption(pMsg, pCreateDbSql);
 
   if (setKeepOption(pCmd, pMsg, pCreateDbSql) != TSDB_CODE_SUCCESS) {
@@ -5776,7 +5780,7 @@ int32_t doLocalQueryProcess(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQ
 }
 
 // can only perform the parameters based on the macro definitation
-int32_t tscCheckCreateDbParams(SSqlCmd* pCmd, SCMCreateDbMsg* pCreate) {
+int32_t tscCheckCreateDbParams(SSqlCmd* pCmd, SCreateDbMsg* pCreate) {
   char msg[512] = {0};
 
   if (pCreate->walLevel != -1 && (pCreate->walLevel < TSDB_MIN_WAL_LEVEL || pCreate->walLevel > TSDB_MAX_WAL_LEVEL)) {
diff --git a/src/client/src/tscSchemaUtil.c b/src/client/src/tscSchemaUtil.c
index 2a9a9de84b..0b1767dd25 100644
--- a/src/client/src/tscSchemaUtil.c
+++ b/src/client/src/tscSchemaUtil.c
@@ -140,7 +140,7 @@ struct SSchema tscGetTbnameColumnSchema() {
   strcpy(s.name, TSQL_TBNAME_L);
   return s;
 }
-static void tscInitCorVgroupInfo(SCMCorVgroupInfo *corVgroupInfo, SCMVgroupInfo *vgroupInfo) {
+static void tscInitCorVgroupInfo(SCorVgroupInfo *corVgroupInfo, SVgroupInfo *vgroupInfo) {
   corVgroupInfo->version = 0;
   corVgroupInfo->inUse = 0;
   corVgroupInfo->numOfEps = vgroupInfo->numOfEps;
@@ -166,7 +166,7 @@ STableMeta* tscCreateTableMetaFromMsg(STableMetaMsg* pTableMetaMsg, size_t* size
   pTableMeta->id.tid = pTableMetaMsg->tid;
   pTableMeta->id.uid = pTableMetaMsg->uid;
 
-  SCMVgroupInfo* pVgroupInfo = &pTableMeta->vgroupInfo;
+  SVgroupInfo* pVgroupInfo = &pTableMeta->vgroupInfo;
   pVgroupInfo->numOfEps = pTableMetaMsg->vgroup.numOfEps;
   pVgroupInfo->vgId = pTableMetaMsg->vgroup.vgId;
 
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 2e7a99f2fb..e10097ed12 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -48,7 +48,7 @@ static int32_t getWaitingTimeInterval(int32_t count) {
   return initial * (2<<(count - 2));
 }
 
-static void tscSetDnodeEpSet(SSqlObj* pSql, SCMVgroupInfo* pVgroupInfo) {
+static void tscSetDnodeEpSet(SSqlObj* pSql, SVgroupInfo* pVgroupInfo) {
   assert(pSql != NULL && pVgroupInfo != NULL && pVgroupInfo->numOfEps > 0);
 
   SRpcEpSet* pEpSet = &pSql->epSet;
@@ -100,7 +100,7 @@ void tscUpdateMgmtEpSet(SRpcEpSet *pEpSet) {
   tscMgmtEpSet.epSet = *pEpSet;
   taosCorEndWrite(&tscMgmtEpSet.version);
 }
-static void tscDumpEpSetFromVgroupInfo(SCMCorVgroupInfo *pVgroupInfo, SRpcEpSet *pEpSet) {
+static void tscDumpEpSetFromVgroupInfo(SCorVgroupInfo *pVgroupInfo, SRpcEpSet *pEpSet) {
   if (pVgroupInfo == NULL) { return;}
   taosCorBeginRead(&pVgroupInfo->version);
   int8_t inUse = pVgroupInfo->inUse;
@@ -117,7 +117,7 @@ static void tscUpdateVgroupInfo(SSqlObj *pObj, SRpcEpSet *pEpSet) {
   SSqlCmd *pCmd = &pObj->cmd;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   if (pTableMetaInfo == NULL || pTableMetaInfo->pTableMeta == NULL) { return;}
-  SCMCorVgroupInfo *pVgroupInfo = &pTableMetaInfo->pTableMeta->corVgroupInfo;
+  SCorVgroupInfo *pVgroupInfo = &pTableMetaInfo->pTableMeta->corVgroupInfo;
 
   taosCorBeginWrite(&pVgroupInfo->version);
   tscDebug("before: Endpoint in use: %d", pVgroupInfo->inUse);
@@ -158,12 +158,12 @@ void tscProcessHeartBeatRsp(void *param, TAOS_RES *tres, int code) {
   SSqlRes *pRes = &pSql->res;
 
   if (code == 0) {
-    SCMHeartBeatRsp *pRsp = (SCMHeartBeatRsp *)pRes->pRsp;
-    SRpcEpSet *      epSet = &pRsp->epSet;
+    SHeartBeatRsp *pRsp = (SHeartBeatRsp *)pRes->pRsp;
+    SRpcEpSet *    epSet = &pRsp->epSet;
     if (epSet->numOfEps > 0) {
       tscEpSetHtons(epSet);
       tscUpdateMgmtEpSet(epSet);
-    } 
+    }
 
     pSql->pTscObj->connId = htonl(pRsp->connId);
 
@@ -584,7 +584,7 @@ static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char
   STableMeta * pTableMeta = pTableMetaInfo->pTableMeta;
   if (UTIL_TABLE_IS_NORMAL_TABLE(pTableMetaInfo) || pTableMetaInfo->pVgroupTables == NULL) {
     
-    SCMVgroupInfo* pVgroupInfo = NULL;
+    SVgroupInfo* pVgroupInfo = NULL;
     if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
       int32_t index = pTableMetaInfo->vgroupIndex;
       assert(index >= 0);
@@ -925,10 +925,10 @@ int tscBuildQueryMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildCreateDbMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMCreateDbMsg);
+  pCmd->payloadLen = sizeof(SCreateDbMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_CREATE_DB;
 
-  SCMCreateDbMsg *pCreateDbMsg = (SCMCreateDbMsg*)pCmd->payload;
+  SCreateDbMsg *pCreateDbMsg = (SCreateDbMsg *)pCmd->payload;
 
   assert(pCmd->numOfClause == 1);
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
@@ -939,13 +939,13 @@ int32_t tscBuildCreateDbMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildCreateDnodeMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMCreateDnodeMsg);
+  pCmd->payloadLen = sizeof(SCreateDnodeMsg);
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMCreateDnodeMsg *pCreate = (SCMCreateDnodeMsg *)pCmd->payload;
+  SCreateDnodeMsg *pCreate = (SCreateDnodeMsg *)pCmd->payload;
   strncpy(pCreate->ep, pInfo->pDCLInfo->a[0].z, pInfo->pDCLInfo->a[0].n);
   
   pCmd->msgType = TSDB_MSG_TYPE_CM_CREATE_DNODE;
@@ -955,13 +955,13 @@ int32_t tscBuildCreateDnodeMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildAcctMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMCreateAcctMsg);
+  pCmd->payloadLen = sizeof(SCreateAcctMsg);
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMCreateAcctMsg *pAlterMsg = (SCMCreateAcctMsg *)pCmd->payload;
+  SCreateAcctMsg *pAlterMsg = (SCreateAcctMsg *)pCmd->payload;
 
   SStrToken *pName = &pInfo->pDCLInfo->user.user;
   SStrToken *pPwd = &pInfo->pDCLInfo->user.passwd;
@@ -1000,14 +1000,14 @@ int32_t tscBuildAcctMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildUserMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMCreateUserMsg);
+  pCmd->payloadLen = sizeof(SCreateUserMsg);
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMCreateUserMsg *pAlterMsg = (SCMCreateUserMsg*)pCmd->payload;
+  SCreateUserMsg *pAlterMsg = (SCreateUserMsg *)pCmd->payload;
 
   SUserInfo *pUser = &pInfo->pDCLInfo->user;
   strncpy(pAlterMsg->user, pUser->user.z, pUser->user.n);
@@ -1032,21 +1032,21 @@ int32_t tscBuildUserMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildCfgDnodeMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMCfgDnodeMsg);
+  pCmd->payloadLen = sizeof(SCfgDnodeMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_CONFIG_DNODE;
   return TSDB_CODE_SUCCESS;
 }
 
 int32_t tscBuildDropDbMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMDropDbMsg);
+  pCmd->payloadLen = sizeof(SDropDbMsg);
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMDropDbMsg *pDropDbMsg = (SCMDropDbMsg*)pCmd->payload;
+  SDropDbMsg *pDropDbMsg = (SDropDbMsg*)pCmd->payload;
 
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   tstrncpy(pDropDbMsg->db, pTableMetaInfo->name, sizeof(pDropDbMsg->db));
@@ -1076,13 +1076,13 @@ int32_t tscBuildDropTableMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildDropDnodeMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMDropDnodeMsg);
+  pCmd->payloadLen = sizeof(SDropDnodeMsg);
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMDropDnodeMsg *pDrop = (SCMDropDnodeMsg *)pCmd->payload;
+  SDropDnodeMsg * pDrop = (SDropDnodeMsg *)pCmd->payload;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   tstrncpy(pDrop->ep, pTableMetaInfo->name, sizeof(pDrop->ep));
   pCmd->msgType = TSDB_MSG_TYPE_CM_DROP_DNODE;
@@ -1092,7 +1092,7 @@ int32_t tscBuildDropDnodeMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildDropUserMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMDropUserMsg);
+  pCmd->payloadLen = sizeof(SDropUserMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_DROP_USER;
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
@@ -1100,7 +1100,7 @@ int32_t tscBuildDropUserMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMDropUserMsg *pDropMsg = (SCMDropUserMsg*)pCmd->payload;
+  SDropUserMsg *  pDropMsg = (SDropUserMsg *)pCmd->payload;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   tstrncpy(pDropMsg->user, pTableMetaInfo->name, sizeof(pDropMsg->user));
 
@@ -1109,7 +1109,7 @@ int32_t tscBuildDropUserMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildDropAcctMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMDropUserMsg);
+  pCmd->payloadLen = sizeof(SDropUserMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_DROP_ACCT;
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
@@ -1117,7 +1117,7 @@ int32_t tscBuildDropAcctMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMDropUserMsg *pDropMsg = (SCMDropUserMsg*)pCmd->payload;
+  SDropUserMsg *  pDropMsg = (SDropUserMsg *)pCmd->payload;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   tstrncpy(pDropMsg->user, pTableMetaInfo->name, sizeof(pDropMsg->user));
 
@@ -1126,14 +1126,14 @@ int32_t tscBuildDropAcctMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int32_t tscBuildUseDbMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMUseDbMsg);
+  pCmd->payloadLen = sizeof(SUseDbMsg);
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMUseDbMsg *pUseDbMsg = (SCMUseDbMsg*)pCmd->payload;
+  SUseDbMsg *pUseDbMsg = (SUseDbMsg *)pCmd->payload;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   strcpy(pUseDbMsg->db, pTableMetaInfo->name);
   pCmd->msgType = TSDB_MSG_TYPE_CM_USE_DB;
@@ -1145,14 +1145,14 @@ int32_t tscBuildShowMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   STscObj *pObj = pSql->pTscObj;
   SSqlCmd *pCmd = &pSql->cmd;
   pCmd->msgType = TSDB_MSG_TYPE_CM_SHOW;
-  pCmd->payloadLen = sizeof(SCMShowMsg) + 100;
+  pCmd->payloadLen = sizeof(SShowMsg) + 100;
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMShowMsg *pShowMsg = (SCMShowMsg*)pCmd->payload;
+  SShowMsg *pShowMsg = (SShowMsg *)pCmd->payload;
 
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   size_t nameLen = strlen(pTableMetaInfo->name);
@@ -1179,13 +1179,13 @@ int32_t tscBuildShowMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     pShowMsg->payloadLen = htons(pEpAddr->n);
   }
 
-  pCmd->payloadLen = sizeof(SCMShowMsg) + pShowMsg->payloadLen;
+  pCmd->payloadLen = sizeof(SShowMsg) + pShowMsg->payloadLen;
   return TSDB_CODE_SUCCESS;
 }
 
 int32_t tscBuildKillMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMKillQueryMsg);
+  pCmd->payloadLen = sizeof(SKillQueryMsg);
 
   switch (pCmd->command) {
     case TSDB_SQL_KILL_QUERY:
@@ -1297,8 +1297,7 @@ int tscBuildCreateTableMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 int tscEstimateAlterTableMsgLength(SSqlCmd *pCmd) {
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
-  return minMsgSize() + sizeof(SCMAlterTableMsg) + sizeof(SSchema) * tscNumOfFields(pQueryInfo) +
-         TSDB_EXTRA_PAYLOAD_SIZE;
+  return minMsgSize() + sizeof(SAlterTableMsg) + sizeof(SSchema) * tscNumOfFields(pQueryInfo) + TSDB_EXTRA_PAYLOAD_SIZE;
 }
 
 int tscBuildAlterTableMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
@@ -1317,7 +1316,7 @@ int tscBuildAlterTableMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
   
-  SCMAlterTableMsg *pAlterTableMsg = (SCMAlterTableMsg *)pCmd->payload;
+  SAlterTableMsg *pAlterTableMsg = (SAlterTableMsg *)pCmd->payload;
   tscGetDBInfoFromTableFullName(pTableMetaInfo->name, pAlterTableMsg->db);
 
   strcpy(pAlterTableMsg->tableId, pTableMetaInfo->name);
@@ -1366,10 +1365,10 @@ int tscBuildUpdateTagMsg(SSqlObj* pSql, SSqlInfo *pInfo) {
 
 int tscAlterDbMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SSqlCmd *pCmd = &pSql->cmd;
-  pCmd->payloadLen = sizeof(SCMAlterDbMsg);
+  pCmd->payloadLen = sizeof(SAlterDbMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_ALTER_DB;
 
-  SCMAlterDbMsg *pAlterDbMsg = (SCMAlterDbMsg*)pCmd->payload;
+  SAlterDbMsg *pAlterDbMsg = (SAlterDbMsg* )pCmd->payload;
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, 0);
   tstrncpy(pAlterDbMsg->db, pTableMetaInfo->name, sizeof(pAlterDbMsg->db));
 
@@ -1494,14 +1493,14 @@ int tscBuildConnectMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   STscObj *pObj = pSql->pTscObj;
   SSqlCmd *pCmd = &pSql->cmd;
   pCmd->msgType = TSDB_MSG_TYPE_CM_CONNECT;
-  pCmd->payloadLen = sizeof(SCMConnectMsg);
+  pCmd->payloadLen = sizeof(SConnectMsg);
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, pCmd->payloadLen)) {
     tscError("%p failed to malloc for query msg", pSql);
     return TSDB_CODE_TSC_OUT_OF_MEMORY;
   }
 
-  SCMConnectMsg *pConnect = (SCMConnectMsg*)pCmd->payload;
+  SConnectMsg *pConnect = (SConnectMsg*)pCmd->payload;
 
   // TODO refactor full_name
   char *db;  // ugly code to move the space
@@ -1523,11 +1522,11 @@ int tscBuildTableMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
   STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
 
-  SCMTableInfoMsg* pInfoMsg = (SCMTableInfoMsg *)pCmd->payload;
+  STableInfoMsg *pInfoMsg = (STableInfoMsg *)pCmd->payload;
   strcpy(pInfoMsg->tableId, pTableMetaInfo->name);
   pInfoMsg->createFlag = htons(pSql->cmd.autoCreated ? 1 : 0);
 
-  char* pMsg = (char*)pInfoMsg + sizeof(SCMTableInfoMsg);
+  char *pMsg = (char *)pInfoMsg + sizeof(STableInfoMsg);
 
   size_t len = htonl(pCmd->tagData.dataLen);
   if (pSql->cmd.autoCreated) {
@@ -1546,7 +1545,7 @@ int tscBuildTableMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
 /**
  *  multi table meta req pkg format:
- *  | SMgmtHead | SCMMultiTableInfoMsg | tableId0 | tableId1 | tableId2 | ......
+ *  | SMgmtHead | SMultiTableInfoMsg | tableId0 | tableId1 | tableId2 | ......
  *      no used         4B
  **/
 int tscBuildMultiMeterMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
@@ -1564,7 +1563,7 @@ int tscBuildMultiMeterMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   SMgmtHead *pMgmt = (SMgmtHead *)(pCmd->payload + tsRpcHeadSize);
   memset(pMgmt->db, 0, TSDB_TABLE_FNAME_LEN);  // server don't need the db
 
-  SCMMultiTableInfoMsg *pInfoMsg = (SCMMultiTableInfoMsg *)(pCmd->payload + tsRpcHeadSize + sizeof(SMgmtHead));
+  SMultiTableInfoMsg *pInfoMsg = (SMultiTableInfoMsg *)(pCmd->payload + tsRpcHeadSize + sizeof(SMgmtHead));
   pInfoMsg->numOfTables = htonl((int32_t)pCmd->count);
 
   if (pCmd->payloadLen > 0) {
@@ -1573,7 +1572,7 @@ int tscBuildMultiMeterMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
   taosTFree(tmpData);
 
-  pCmd->payloadLen += sizeof(SMgmtHead) + sizeof(SCMMultiTableInfoMsg);
+  pCmd->payloadLen += sizeof(SMgmtHead) + sizeof(SMultiTableInfoMsg);
   pCmd->msgType = TSDB_MSG_TYPE_CM_TABLES_META;
 
   assert(pCmd->payloadLen + minMsgSize() <= pCmd->allocSize);
@@ -1618,12 +1617,12 @@ int tscBuildSTableVgroupMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   
   char* pMsg = pCmd->payload;
   SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
-  
-  SCMSTableVgroupMsg *pStableVgroupMsg = (SCMSTableVgroupMsg *) pMsg;
+
+  SSTableVgroupMsg *pStableVgroupMsg = (SSTableVgroupMsg *)pMsg;
   pStableVgroupMsg->numOfTables = htonl(pQueryInfo->numOfTables);
-  pMsg += sizeof(SCMSTableVgroupMsg);
-  
-  for(int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+  pMsg += sizeof(SSTableVgroupMsg);
+
+  for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
     STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, i);
     size_t size = sizeof(pTableMetaInfo->name);
     tstrncpy(pMsg, pTableMetaInfo->name, size);
@@ -1656,7 +1655,7 @@ int tscBuildHeartBeatMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     numOfStreams++;
   }
 
-  int size = numOfQueries * sizeof(SQueryDesc) + numOfStreams * sizeof(SStreamDesc) + sizeof(SCMHeartBeatMsg) + 100;
+  int size = numOfQueries * sizeof(SQueryDesc) + numOfStreams * sizeof(SStreamDesc) + sizeof(SHeartBeatMsg) + 100;
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, size)) {
     pthread_mutex_unlock(&pObj->mutex);
     tscError("%p failed to create heartbeat msg", pSql);
@@ -1664,7 +1663,7 @@ int tscBuildHeartBeatMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
   }
 
   // TODO the expired hb and client can not be identified by server till now.
-  SCMHeartBeatMsg *pHeartbeat = (SCMHeartBeatMsg *)pCmd->payload;
+  SHeartBeatMsg *pHeartbeat = (SHeartBeatMsg *)pCmd->payload;
   tstrncpy(pHeartbeat->clientVer, version, tListLen(pHeartbeat->clientVer));
 
   pHeartbeat->numOfQueries = numOfQueries;
@@ -1755,7 +1754,7 @@ int tscProcessTableMetaRsp(SSqlObj *pSql) {
 
 /**
  *  multi table meta rsp pkg format:
- *  | STaosRsp | ieType | SCMMultiTableInfoMsg | SMeterMeta0 | SSchema0 | SMeterMeta1 | SSchema1 | SMeterMeta2 | SSchema2
+ *  | STaosRsp | ieType | SMultiTableInfoMsg | SMeterMeta0 | SSchema0 | SMeterMeta1 | SSchema1 | SMeterMeta2 | SSchema2
  *  |...... 1B        1B            4B
  **/
 int tscProcessMultiMeterMetaRsp(SSqlObj *pSql) {
@@ -1772,9 +1771,9 @@ int tscProcessMultiMeterMetaRsp(SSqlObj *pSql) {
 
   rsp++;
 
-  SCMMultiTableInfoMsg *pInfo = (SCMMultiTableInfoMsg *)rsp;
+  SMultiTableInfoMsg *pInfo = (SMultiTableInfoMsg *)rsp;
   totalNum = htonl(pInfo->numOfTables);
-  rsp += sizeof(SCMMultiTableInfoMsg);
+  rsp += sizeof(SMultiTableInfoMsg);
 
   for (i = 0; i < totalNum; i++) {
     SMultiTableMeta *pMultiMeta = (SMultiTableMeta *)rsp;
@@ -1866,10 +1865,10 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
   SSqlRes* pRes = &pSql->res;
   
   // NOTE: the order of several table must be preserved.
-  SCMSTableVgroupRspMsg *pStableVgroup = (SCMSTableVgroupRspMsg *)pRes->pRsp;
+  SSTableVgroupRspMsg *pStableVgroup = (SSTableVgroupRspMsg *)pRes->pRsp;
   pStableVgroup->numOfTables = htonl(pStableVgroup->numOfTables);
-  char* pMsg = pRes->pRsp + sizeof(SCMSTableVgroupRspMsg);
-  
+  char *pMsg = pRes->pRsp + sizeof(SSTableVgroupRspMsg);
+
   // master sqlObj locates in param
   SSqlObj* parent = pSql->param;
   assert(parent != NULL);
@@ -1881,18 +1880,18 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
     SVgroupsMsg *  pVgroupMsg = (SVgroupsMsg *) pMsg;
     pVgroupMsg->numOfVgroups = htonl(pVgroupMsg->numOfVgroups);
 
-    size_t size = sizeof(SCMVgroupMsg) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsMsg);
+    size_t size = sizeof(SVgroupMsg) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsMsg);
 
-    size_t vgroupsz = sizeof(SCMVgroupInfo) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsInfo);
+    size_t vgroupsz = sizeof(SVgroupInfo) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsInfo);
     pInfo->vgroupList = calloc(1, vgroupsz);
     assert(pInfo->vgroupList != NULL);
 
     pInfo->vgroupList->numOfVgroups = pVgroupMsg->numOfVgroups;
     for (int32_t j = 0; j < pInfo->vgroupList->numOfVgroups; ++j) {
       //just init, no need to lock
-      SCMVgroupInfo *pVgroups = &pInfo->vgroupList->vgroups[j];
+      SVgroupInfo *pVgroups = &pInfo->vgroupList->vgroups[j];
 
-      SCMVgroupMsg *vmsg = &pVgroupMsg->vgroups[j];
+      SVgroupMsg *vmsg = &pVgroupMsg->vgroups[j];
       pVgroups->vgId = htonl(vmsg->vgId);
       pVgroups->numOfEps = vmsg->numOfEps;
 
@@ -1914,10 +1913,10 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
  * current process do not use the cache at all
  */
 int tscProcessShowRsp(SSqlObj *pSql) {
-  STableMetaMsg * pMetaMsg;
-  SCMShowRsp *pShow;
-  SSchema *    pSchema;
-  char         key[20];
+  STableMetaMsg *pMetaMsg;
+  SShowRsp *     pShow;
+  SSchema *      pSchema;
+  char           key[20];
 
   SSqlRes *pRes = &pSql->res;
   SSqlCmd *pCmd = &pSql->cmd;
@@ -1926,7 +1925,7 @@ int tscProcessShowRsp(SSqlObj *pSql) {
 
   STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
 
-  pShow = (SCMShowRsp *)pRes->pRsp;
+  pShow = (SShowRsp *)pRes->pRsp;
   pShow->qhandle = htobe64(pShow->qhandle);
   pRes->qhandle = pShow->qhandle;
 
@@ -2024,7 +2023,7 @@ int tscProcessConnectRsp(SSqlObj *pSql) {
 
   char temp[TSDB_TABLE_FNAME_LEN * 2] = {0};
 
-  SCMConnectRsp *pConnect = (SCMConnectRsp *)pRes->pRsp;
+  SConnectRsp *pConnect = (SConnectRsp *)pRes->pRsp;
   tstrncpy(pObj->acctId, pConnect->acctId, sizeof(pObj->acctId));  // copy acctId from response
   int32_t len = sprintf(temp, "%s%s%s", pObj->acctId, TS_PATH_DELIMITER, pObj->db);
 
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 3e907e5d77..0cd463c4f5 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -509,7 +509,7 @@ void tscBuildVgroupTableInfo(SSqlObj* pSql, STableMetaInfo* pTableMetaInfo, SArr
       SVgroupTableInfo info = {{0}};
       for (int32_t m = 0; m < pvg->numOfVgroups; ++m) {
         if (tt->vgId == pvg->vgroups[m].vgId) {
-          tscSCMVgroupInfoCopy(&info.vgInfo, &pvg->vgroups[m]);
+          tscSVgroupInfoCopy(&info.vgInfo, &pvg->vgroups[m]);
           break;
         }
       }
@@ -1449,6 +1449,7 @@ void tscHandleMasterJoinQuery(SSqlObj* pSql) {
 
   tscDebug("%p start subquery, total:%d", pSql, pQueryInfo->numOfTables);
   for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+
     SJoinSupporter *pSupporter = tscCreateJoinSupporter(pSql, i);
     
     if (pSupporter == NULL) {  // failed to create support struct, abort current query
@@ -1670,8 +1671,8 @@ static int32_t tscReissueSubquery(SRetrieveSupport *trsupport, SSqlObj *pSql, in
   SSqlObj *pParentSql = trsupport->pParentSql;
   int32_t  subqueryIndex = trsupport->subqueryIndex;
 
-  STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, 0, 0);
-  SCMVgroupInfo* pVgroup = &pTableMetaInfo->vgroupList->vgroups[0];
+  STableMetaInfo* pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, 0, 0);
+  SVgroupInfo* pVgroup = &pTableMetaInfo->vgroupList->vgroups[0];
 
   tExtMemBufferClear(trsupport->pExtMemBuffer[subqueryIndex]);
 
@@ -1873,7 +1874,7 @@ static void tscRetrieveFromDnodeCallBack(void *param, TAOS_RES *tres, int numOfR
   assert(pState->numOfRemain <= pState->numOfSub && pState->numOfRemain >= 0);
   
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, 0, 0);
-  SCMVgroupInfo  *pVgroup = &pTableMetaInfo->vgroupList->vgroups[0];
+  SVgroupInfo  *pVgroup = &pTableMetaInfo->vgroupList->vgroups[0];
 
   if (pParentSql->res.code != TSDB_CODE_SUCCESS) {
     trsupport->numOfRetry = MAX_NUM_OF_SUBQUERY_RETRY;
@@ -1984,7 +1985,7 @@ void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code) {
   assert(pSql->cmd.numOfClause == 1 && pQueryInfo->numOfTables == 1);
   
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, 0, 0);
-  SCMVgroupInfo* pVgroup = &pTableMetaInfo->vgroupList->vgroups[trsupport->subqueryIndex];
+  SVgroupInfo* pVgroup = &pTableMetaInfo->vgroupList->vgroups[trsupport->subqueryIndex];
 
   // stable query killed or other subquery failed, all query stopped
   if (pParentSql->res.code != TSDB_CODE_SUCCESS) {
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 77d668c5af..839d5889f3 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -104,7 +104,6 @@ void taos_init_imp(void) {
 
     taosReadGlobalCfg();
     taosCheckGlobalCfg();
-    taosPrintGlobalCfg();
 
     tscDebug("starting to initialize TAOS client ...");
     tscDebug("Local End Point is:%s", tsLocalEp);
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index e2cc440335..ad518ab3f3 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2158,7 +2158,7 @@ int16_t tscGetJoinTagColIdByUid(STagCond* pTagCond, uint64_t uid) {
 }
 
 int16_t tscGetTagColIndexById(STableMeta* pTableMeta, int16_t colId) {
-  int32_t numOfTags = tscGetNumOfColumns(pTableMeta);
+  int32_t numOfTags = tscGetNumOfTags(pTableMeta);
 
   SSchema* pSchema = tscGetTableTagSchema(pTableMeta);
   for(int32_t i = 0; i < numOfTags; ++i) {
@@ -2167,7 +2167,9 @@ int16_t tscGetTagColIndexById(STableMeta* pTableMeta, int16_t colId) {
     }
   }
 
-  return -1;
+  // can not reach here
+  assert(0);
+  return INT16_MIN;
 }
 
 bool tscIsUpdateQuery(SSqlObj* pSql) {
@@ -2439,7 +2441,7 @@ SVgroupsInfo* tscVgroupInfoClone(SVgroupsInfo *vgroupList) {
     return NULL;
   }
 
-  size_t size = sizeof(SVgroupsInfo) + sizeof(SCMVgroupInfo) * vgroupList->numOfVgroups;
+  size_t size = sizeof(SVgroupsInfo) + sizeof(SVgroupInfo) * vgroupList->numOfVgroups;
   SVgroupsInfo* pNew = calloc(1, size);
   if (pNew == NULL) {
     return NULL;
@@ -2448,9 +2450,9 @@ SVgroupsInfo* tscVgroupInfoClone(SVgroupsInfo *vgroupList) {
   pNew->numOfVgroups = vgroupList->numOfVgroups;
 
   for(int32_t i = 0; i < vgroupList->numOfVgroups; ++i) {
-    SCMVgroupInfo* pNewVInfo = &pNew->vgroups[i];
+    SVgroupInfo* pNewVInfo = &pNew->vgroups[i];
 
-    SCMVgroupInfo* pvInfo = &vgroupList->vgroups[i];
+    SVgroupInfo* pvInfo = &vgroupList->vgroups[i];
     pNewVInfo->vgId = pvInfo->vgId;
     pNewVInfo->numOfEps = pvInfo->numOfEps;
 
@@ -2469,7 +2471,7 @@ void* tscVgroupInfoClear(SVgroupsInfo *vgroupList) {
   }
 
   for(int32_t i = 0; i < vgroupList->numOfVgroups; ++i) {
-    SCMVgroupInfo* pVgroupInfo = &vgroupList->vgroups[i];
+    SVgroupInfo* pVgroupInfo = &vgroupList->vgroups[i];
 
     for(int32_t j = 0; j < pVgroupInfo->numOfEps; ++j) {
       taosTFree(pVgroupInfo->epAddr[j].fqdn);
@@ -2480,7 +2482,7 @@ void* tscVgroupInfoClear(SVgroupsInfo *vgroupList) {
   return NULL;
 }
 
-void tscSCMVgroupInfoCopy(SCMVgroupInfo* dst, const SCMVgroupInfo* src) {
+void tscSVgroupInfoCopy(SVgroupInfo* dst, const SVgroupInfo* src) {
   dst->vgId = src->vgId;
   dst->numOfEps = src->numOfEps;
   for(int32_t i = 0; i < dst->numOfEps; ++i) {
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index 260715dbd1..dbcf50ba77 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -51,6 +51,7 @@ extern char     tsLocale[];
 extern char     tsCharset[];            // default encode string
 extern int32_t  tsEnableCoreFile;
 extern int32_t  tsCompressMsgSize;
+extern char     tsTempDir[];
 
 //query buffer management
 extern int32_t  tsQueryBufferSize;      // maximum allowed usage buffer for each data node during query processing
@@ -184,13 +185,13 @@ extern int32_t debugFlag;
 
 #define NEEDTO_COMPRESSS_MSG(size) (tsCompressMsgSize != -1 && (size) > tsCompressMsgSize)
 
-void taosInitGlobalCfg();
-bool taosCheckGlobalCfg();
-void taosSetAllDebugFlag();
-bool taosCfgDynamicOptions(char *msg);
-int  taosGetFqdnPortFromEp(const char *ep, char *fqdn, uint16_t *port);
-bool taosCheckBalanceCfgOptions(const char *option, int32_t *vnodeId, int32_t *dnodeId);
- 
+void    taosInitGlobalCfg();
+int32_t taosCheckGlobalCfg();
+void    taosSetAllDebugFlag();
+bool    taosCfgDynamicOptions(char *msg);
+int     taosGetFqdnPortFromEp(const char *ep, char *fqdn, uint16_t *port);
+bool    taosCheckBalanceCfgOptions(const char *option, int32_t *vnodeId, int32_t *dnodeId);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 9f5cc97916..75c8f93a82 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -58,6 +58,7 @@ char    tsLocale[TSDB_LOCALE_LEN] = {0};
 char    tsCharset[TSDB_LOCALE_LEN] = {0};  // default encode string
 int32_t tsEnableCoreFile = 0;
 int32_t tsMaxBinaryDisplayWidth = 30;
+char    tsTempDir[TSDB_FILENAME_LEN] = "/tmp/";
 
 /*
  * denote if the server needs to compress response message at the application layer to client, including query rsp,
@@ -1321,13 +1322,23 @@ static void doInitGlobalConfig(void) {
   cfg.ptrLength = 0;
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
+
+  cfg.option = "tempDir";
+  cfg.ptr = tsTempDir;
+  cfg.valType = TAOS_CFG_VTYPE_STRING;
+  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT;
+  cfg.minValue = 0;
+  cfg.maxValue = 0;
+  cfg.ptrLength = tListLen(tsTempDir);
+  cfg.unitType = TAOS_CFG_UTYPE_NONE;
+  taosInitConfigOption(cfg);
 }
 
 void taosInitGlobalCfg() {
   pthread_once(&tsInitGlobalCfgOnce, doInitGlobalConfig);
 }
 
-bool taosCheckGlobalCfg() {
+int32_t taosCheckGlobalCfg() {
   char fqdn[TSDB_FQDN_LEN];
   uint16_t port;
 
@@ -1386,7 +1397,9 @@ bool taosCheckGlobalCfg() {
   tsSyncPort = tsServerPort + TSDB_PORT_SYNC;
   tsHttpPort = tsServerPort + TSDB_PORT_HTTP;
 
-  return true;
+  taosPrintGlobalCfg();
+
+  return 0;
 }
 
 int taosGetFqdnPortFromEp(const char *ep, char *fqdn, uint16_t *port) {
diff --git a/src/connector/go b/src/connector/go
index 8d7bf74385..8c58c512b6 160000
--- a/src/connector/go
+++ b/src/connector/go
@@ -1 +1 @@
-Subproject commit 8d7bf743852897110cbdcc7c4322cd7a74d4167b
+Subproject commit 8c58c512b6acda8bcdfa48fdc7140227b5221766
diff --git a/src/dnode/inc/dnodeCfg.h b/src/dnode/inc/dnodeCfg.h
new file mode 100644
index 0000000000..35d8896460
--- /dev/null
+++ b/src/dnode/inc/dnodeCfg.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_DNODE_CFG_H
+#define TDENGINE_DNODE_CFG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int32_t dnodeInitCfg();
+void    dnodeCleanupCfg();
+void    dnodeUpdateCfg(SDnodeCfg *cfg);
+int32_t dnodeGetDnodeId();
+void    dnodeGetCfg(int32_t *dnodeId, char *clusterId);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/dnode/inc/dnodeEps.h b/src/dnode/inc/dnodeEps.h
new file mode 100644
index 0000000000..2a203498c1
--- /dev/null
+++ b/src/dnode/inc/dnodeEps.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_DNODE_EP_H
+#define TDENGINE_DNODE_EP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "taosmsg.h"
+
+int32_t dnodeInitEps();
+void    dnodeCleanupEps();
+void    dnodeUpdateEps(SDnodeEps *eps);
+void    dnodeUpdateEp(int32_t dnodeId, char *epstr, char *fqdn, uint16_t *port);
+bool    dnodeCheckEpChanged(int32_t dnodeId, char *epstr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/dnode/inc/dnodeMInfos.h b/src/dnode/inc/dnodeMInfos.h
new file mode 100644
index 0000000000..9c3c85c47e
--- /dev/null
+++ b/src/dnode/inc/dnodeMInfos.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_DNODE_MINFOS_H
+#define TDENGINE_DNODE_MINFOS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "taosmsg.h"
+
+int32_t dnodeInitMInfos();
+void    dnodeCleanupMInfos();
+void    dnodeUpdateMInfos(SMnodeInfos *minfos);
+void    dnodeUpdateEpSetForPeer(SRpcEpSet *epSet);
+void    dnodeGetMInfos(SMnodeInfos *minfos);
+bool    dnodeIsMasterEp(char *ep);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/dnode/inc/dnodeMgmt.h b/src/dnode/inc/dnodeMgmt.h
index e8f4a0823f..2038ef5286 100644
--- a/src/dnode/inc/dnodeMgmt.h
+++ b/src/dnode/inc/dnodeMgmt.h
@@ -20,6 +20,8 @@
 extern "C" {
 #endif
 
+#include "trpc.h"
+
 int32_t dnodeInitMgmt();
 void    dnodeCleanupMgmt();
 int32_t dnodeInitMgmtTimer();
@@ -35,8 +37,8 @@ void*   dnodeGetVnodeTsdb(void *pVnode);
 void    dnodeReleaseVnode(void *pVnode);
 
 void    dnodeSendRedirectMsg(SRpcMsg *rpcMsg, bool forShell);
-void    dnodeGetMnodeEpSetForPeer(void *epSet);
-void    dnodeGetMnodeEpSetForShell(void *epSet);
+void    dnodeGetEpSetForPeer(SRpcEpSet *epSet);
+void    dnodeGetEpSetForShell(SRpcEpSet *epSet);
 
 #ifdef __cplusplus
 }
diff --git a/src/dnode/src/dnodeCfg.c b/src/dnode/src/dnodeCfg.c
new file mode 100644
index 0000000000..16d109a13a
--- /dev/null
+++ b/src/dnode/src/dnodeCfg.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "cJSON.h"
+#include "tglobal.h"
+#include "dnode.h"
+#include "dnodeInt.h"
+#include "dnodeCfg.h"
+
+static SDnodeCfg tsCfg = {0};
+static pthread_mutex_t tsCfgMutex;
+
+static int32_t dnodeReadCfg();
+static int32_t dnodeWriteCfg();
+static void    dnodeResetCfg(SDnodeCfg *cfg);
+static void    dnodePrintCfg(SDnodeCfg *cfg);
+
+int32_t dnodeInitCfg() {
+  pthread_mutex_init(&tsCfgMutex, NULL);
+  dnodeResetCfg(NULL);
+  int32_t ret = dnodeReadCfg();
+  if (ret == 0) {
+    dInfo("dnode cfg is initialized");
+  }
+  return ret;
+}
+
+void dnodeCleanupCfg() { pthread_mutex_destroy(&tsCfgMutex); }
+
+void dnodeUpdateCfg(SDnodeCfg *cfg) {
+  if (tsCfg.dnodeId != 0) return;
+  dnodeResetCfg(cfg);
+}
+
+int32_t dnodeGetDnodeId() {
+  int32_t dnodeId = 0;
+  pthread_mutex_lock(&tsCfgMutex);
+  dnodeId = tsCfg.dnodeId;
+  pthread_mutex_unlock(&tsCfgMutex);
+  return dnodeId;
+}
+
+void dnodeGetCfg(int32_t *dnodeId, char *clusterId) {
+  pthread_mutex_lock(&tsCfgMutex);
+  *dnodeId = tsCfg.dnodeId;
+  tstrncpy(clusterId, tsCfg.clusterId, TSDB_CLUSTER_ID_LEN);
+  pthread_mutex_unlock(&tsCfgMutex);
+}
+
+static void dnodeResetCfg(SDnodeCfg *cfg) {
+  if (cfg == NULL) return;
+  if (cfg->dnodeId == 0) return;
+
+  pthread_mutex_lock(&tsCfgMutex);
+  tsCfg.dnodeId = cfg->dnodeId;
+  tstrncpy(tsCfg.clusterId, cfg->clusterId, TSDB_CLUSTER_ID_LEN);
+  dnodePrintCfg(cfg);
+  dnodeWriteCfg();
+  pthread_mutex_unlock(&tsCfgMutex);
+}
+
+static void dnodePrintCfg(SDnodeCfg *cfg) {
+  dInfo("dnodeId is set to %d, clusterId is set to %s", cfg->dnodeId, cfg->clusterId);
+}
+
+static int32_t dnodeReadCfg() {
+  int32_t   len = 0;
+  int32_t   maxLen = 200;
+  char *    content = calloc(1, maxLen + 1);
+  cJSON *   root = NULL;
+  FILE *    fp = NULL;
+  SDnodeCfg cfg = {0};
+
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/dnodeCfg.json", tsDnodeDir);
+
+  fp = fopen(file, "r");
+  if (!fp) {
+    dDebug("failed to read %s, file not exist", file);
+    goto PARSE_CFG_OVER;
+  }
+
+  len = fread(content, 1, maxLen, fp);
+  if (len <= 0) {
+    dError("failed to read %s, content is null", file);
+    goto PARSE_CFG_OVER;
+  }
+
+  content[len] = 0;
+  root = cJSON_Parse(content);
+  if (root == NULL) {
+    dError("failed to read %s, invalid json format", file);
+    goto PARSE_CFG_OVER;
+  }
+
+  cJSON *dnodeId = cJSON_GetObjectItem(root, "dnodeId");
+  if (!dnodeId || dnodeId->type != cJSON_Number) {
+    dError("failed to read %s, dnodeId not found", file);
+    goto PARSE_CFG_OVER;
+  }
+  cfg.dnodeId = dnodeId->valueint;
+
+  cJSON *clusterId = cJSON_GetObjectItem(root, "clusterId");
+  if (!clusterId || clusterId->type != cJSON_String) {
+    dError("failed to read %s, clusterId not found", file);
+    goto PARSE_CFG_OVER;
+  }
+  tstrncpy(cfg.clusterId, clusterId->valuestring, TSDB_CLUSTER_ID_LEN);
+
+  dInfo("read file %s successed", file);
+
+PARSE_CFG_OVER:
+  if (content != NULL) free(content);
+  if (root != NULL) cJSON_Delete(root);
+  if (fp != NULL) fclose(fp);
+  terrno = 0;
+
+  dnodeResetCfg(&cfg);
+  return 0;
+}
+
+static int32_t dnodeWriteCfg() {
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/dnodeCfg.json", tsDnodeDir);
+
+  FILE *fp = fopen(file, "w");
+  if (!fp) {
+    dError("failed to write %s, reason:%s", file, strerror(errno));
+    return -1;
+  }
+
+  int32_t len = 0;
+  int32_t maxLen = 200;
+  char *  content = calloc(1, maxLen + 1);
+
+  len += snprintf(content + len, maxLen - len, "{\n");
+  len += snprintf(content + len, maxLen - len, "  \"dnodeId\": %d,\n", tsCfg.dnodeId);
+  len += snprintf(content + len, maxLen - len, "  \"clusterId\": \"%s\"\n", tsCfg.clusterId);
+  len += snprintf(content + len, maxLen - len, "}\n");
+
+  fwrite(content, 1, len, fp);
+  fflush(fp);
+  fclose(fp);
+  free(content);
+  terrno = 0;
+
+  dInfo("successed to write %s", file);
+  return 0;
+}
diff --git a/src/dnode/src/dnodeCheck.c b/src/dnode/src/dnodeCheck.c
index 9b68fc1f6c..a9ee4ac649 100644
--- a/src/dnode/src/dnodeCheck.c
+++ b/src/dnode/src/dnodeCheck.c
@@ -15,9 +15,7 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
-#include "taosdef.h"
 #include "tglobal.h"
-#include "mnode.h"
 #include "dnodeInt.h"
 #include "dnodeCheck.h"
 
@@ -30,8 +28,8 @@ typedef struct {
   void    (*stopFp)();
 } SCheckItem;
 
-static    SCheckItem  tsCheckItem[TSDB_CHECK_ITEM_MAX] = {{0}};
-int64_t   tsMinFreeMemSizeForStart = 0;
+static  SCheckItem  tsCheckItem[TSDB_CHECK_ITEM_MAX] = {{0}};
+int64_t tsMinFreeMemSizeForStart = 0;
 
 static int bindTcpPort(int port) {
   int    serverSocket;
@@ -264,8 +262,6 @@ int32_t dnodeInitCheck() {
     }
   }
 
+  dInfo("dnode check is initialized");
   return 0;
 }
-
-
-
diff --git a/src/dnode/src/dnodeEps.c b/src/dnode/src/dnodeEps.c
new file mode 100644
index 0000000000..9c90c39181
--- /dev/null
+++ b/src/dnode/src/dnodeEps.c
@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "cJSON.h"
+#include "tglobal.h"
+#include "hash.h"
+#include "dnode.h"
+#include "dnodeInt.h"
+#include "dnodeEps.h"
+
+static SDnodeEps *tsEps = NULL;
+static SHashObj * tsEpsHash = NULL;
+static pthread_mutex_t tsEpsMutex;
+
+static int32_t dnodeReadEps();
+static int32_t dnodeWriteEps();
+static void    dnodeResetEps(SDnodeEps *eps);
+static void    dnodePrintEps(SDnodeEps *eps);
+
+int32_t dnodeInitEps() {
+  pthread_mutex_init(&tsEpsMutex, NULL);
+  tsEpsHash = taosHashInit(4, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, true);
+  dnodeResetEps(NULL);
+  int32_t ret = dnodeReadEps();
+  if (ret == 0) {
+    dInfo("dnode eps is initialized");
+  }
+  return ret;
+}
+
+void dnodeCleanupEps() {
+  pthread_mutex_lock(&tsEpsMutex);
+  if (tsEps) {
+    free(tsEps);
+    tsEps = NULL;
+  }
+  if (tsEpsHash) {
+    taosHashCleanup(tsEpsHash);
+    tsEpsHash = NULL;
+  }
+  pthread_mutex_unlock(&tsEpsMutex);
+  pthread_mutex_destroy(&tsEpsMutex);
+}
+
+void dnodeUpdateEps(SDnodeEps *eps) {
+  if (eps == NULL) return;
+
+  eps->dnodeNum = htonl(eps->dnodeNum);
+  for (int32_t i = 0; i < eps->dnodeNum; ++i) {
+    eps->dnodeEps[i].dnodeId = htonl(eps->dnodeEps[i].dnodeId);
+    eps->dnodeEps[i].dnodePort = htons(eps->dnodeEps[i].dnodePort);
+  }
+
+  pthread_mutex_lock(&tsEpsMutex);
+  if (eps->dnodeNum != tsEps->dnodeNum) {
+    dnodeResetEps(eps);
+    dnodeWriteEps();
+  } else {
+    int32_t size = sizeof(SDnodeEps) + eps->dnodeNum * sizeof(SDnodeEp);
+    if (memcmp(eps, tsEps, size) != 0) {
+      dnodeResetEps(eps);
+      dnodeWriteEps();
+    }
+  }
+  pthread_mutex_unlock(&tsEpsMutex);
+}
+
+bool dnodeCheckEpChanged(int32_t dnodeId, char *epstr) {
+  bool changed = false;
+  pthread_mutex_lock(&tsEpsMutex);
+  SDnodeEp *ep = taosHashGet(tsEpsHash, &dnodeId, sizeof(int32_t));
+  if (ep != NULL) {
+    char epSaved[TSDB_EP_LEN + 1];
+    snprintf(epSaved, TSDB_EP_LEN, "%s:%u", ep->dnodeFqdn, ep->dnodePort);
+    changed = strcmp(epstr, epSaved) != 0;
+    tstrncpy(epstr, epSaved, TSDB_EP_LEN);
+  }
+  pthread_mutex_unlock(&tsEpsMutex);
+  return changed;
+}
+
+void dnodeUpdateEp(int32_t dnodeId, char *epstr, char *fqdn, uint16_t *port) {
+  pthread_mutex_lock(&tsEpsMutex);
+  SDnodeEp *ep = taosHashGet(tsEpsHash, &dnodeId, sizeof(int32_t));
+  if (ep != NULL) {
+    if (port) *port = ep->dnodePort;
+    if (fqdn) tstrncpy(fqdn, ep->dnodeFqdn, TSDB_FQDN_LEN);
+    if (epstr) snprintf(epstr, TSDB_EP_LEN, "%s:%u", ep->dnodeFqdn, ep->dnodePort);
+  }
+  pthread_mutex_unlock(&tsEpsMutex);
+}
+
+static void dnodeResetEps(SDnodeEps *eps) {
+  if (eps == NULL) {
+    int32_t size = sizeof(SDnodeEps) + sizeof(SDnodeEp);
+    if (tsEps == NULL) {
+      tsEps = calloc(1, size);
+    } else {
+      tsEps->dnodeNum = 0;
+    }
+  } else {
+    assert(tsEps);
+
+    int32_t size = sizeof(SDnodeEps) + sizeof(SDnodeEp) * eps->dnodeNum;
+    if (eps->dnodeNum > tsEps->dnodeNum) {
+      tsEps = realloc(tsEps, size);
+    }
+    memcpy(tsEps, eps, size);
+    dnodePrintEps(eps);
+  }
+
+  for (int32_t i = 0; i < tsEps->dnodeNum; ++i) {
+    SDnodeEp *ep = &tsEps->dnodeEps[i];
+    taosHashPut(tsEpsHash, &ep->dnodeId, sizeof(int32_t), ep, sizeof(SDnodeEp));
+  }
+}
+
+static void dnodePrintEps(SDnodeEps *eps) {
+  dDebug("print dnodeEp, dnodeNum:%d", eps->dnodeNum);
+  for (int32_t i = 0; i < eps->dnodeNum; i++) {
+    SDnodeEp *ep = &eps->dnodeEps[i];
+    dDebug("dnodeId:%d, dnodeFqdn:%s dnodePort:%u", ep->dnodeId, ep->dnodeFqdn, ep->dnodePort);
+  }
+}
+
+static int32_t dnodeReadEps() {
+  int32_t    ret = -1;
+  int32_t    len = 0;
+  int32_t    maxLen = 30000;
+  char *     content = calloc(1, maxLen + 1);
+  cJSON *    root = NULL;
+  FILE *     fp = NULL;
+  SDnodeEps *eps = NULL;
+
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/dnodeEps.json", tsDnodeDir);
+
+  fp = fopen(file, "r");
+  if (!fp) {
+    dDebug("failed to read %s, file not exist", file);
+    goto PRASE_EPS_OVER;
+  }
+
+  len = fread(content, 1, maxLen, fp);
+  if (len <= 0) {
+    dError("failed to read %s, content is null", file);
+    goto PRASE_EPS_OVER;
+  }
+
+  content[len] = 0;
+  root = cJSON_Parse(content);
+  if (root == NULL) {
+    dError("failed to read %s, invalid json format", file);
+    goto PRASE_EPS_OVER;
+  }
+
+  cJSON *dnodeNum = cJSON_GetObjectItem(root, "dnodeNum");
+  if (!dnodeNum || dnodeNum->type != cJSON_Number) {
+    dError("failed to read %s, dnodeNum not found", file);
+    goto PRASE_EPS_OVER;
+  }
+
+  cJSON *dnodeInfos = cJSON_GetObjectItem(root, "dnodeInfos");
+  if (!dnodeInfos || dnodeInfos->type != cJSON_Array) {
+    dError("failed to read %s, dnodeInfos not found", file);
+    goto PRASE_EPS_OVER;
+  }
+
+  int32_t dnodeInfosSize = cJSON_GetArraySize(dnodeInfos);
+  if (dnodeInfosSize != dnodeNum->valueint) {
+    dError("failed to read %s, dnodeInfos size:%d not matched dnodeNum:%d", file, dnodeInfosSize,
+           (int32_t)dnodeNum->valueint);
+    goto PRASE_EPS_OVER;
+  }
+
+  int32_t epsSize = sizeof(SDnodeEps) + dnodeInfosSize * sizeof(SDnodeEp);
+  eps = calloc(1, epsSize);
+  eps->dnodeNum = dnodeInfosSize;
+
+  for (int32_t i = 0; i < dnodeInfosSize; ++i) {
+    cJSON *dnodeInfo = cJSON_GetArrayItem(dnodeInfos, i);
+    if (dnodeInfo == NULL) break;
+
+    SDnodeEp *ep = &eps->dnodeEps[i];
+
+    cJSON *dnodeId = cJSON_GetObjectItem(dnodeInfo, "dnodeId");
+    if (!dnodeId || dnodeId->type != cJSON_Number) {
+      dError("failed to read %s, dnodeId not found", file);
+      goto PRASE_EPS_OVER;
+    }
+    ep->dnodeId = dnodeId->valueint;
+
+    cJSON *dnodeFqdn = cJSON_GetObjectItem(dnodeInfo, "dnodeFqdn");
+    if (!dnodeFqdn || dnodeFqdn->type != cJSON_String || dnodeFqdn->valuestring == NULL) {
+      dError("failed to read %s, dnodeFqdn not found", file);
+      goto PRASE_EPS_OVER;
+    }
+    strncpy(ep->dnodeFqdn, dnodeFqdn->valuestring, TSDB_FQDN_LEN);
+
+    cJSON *dnodePort = cJSON_GetObjectItem(dnodeInfo, "dnodePort");
+    if (!dnodePort || dnodePort->type != cJSON_Number) {
+      dError("failed to read %s, dnodePort not found", file);
+      goto PRASE_EPS_OVER;
+    }
+    ep->dnodePort = (uint16_t)dnodePort->valueint;
+  }
+
+  ret = 0;
+
+  dInfo("read file %s successed", file);
+  dnodePrintEps(eps);
+
+PRASE_EPS_OVER:
+  if (content != NULL) free(content);
+  if (root != NULL) cJSON_Delete(root);
+  if (fp != NULL) fclose(fp);
+  if (ret != 0) {
+    if (eps) free(eps);
+    eps = NULL;
+  }
+
+  dnodeResetEps(eps);
+  if (eps) free(eps);
+
+  dnodeUpdateEp(dnodeGetDnodeId(), tsLocalEp, tsLocalFqdn, &tsServerPort);
+
+  terrno = 0;
+  return 0;
+}
+
+static int32_t dnodeWriteEps() {
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/dnodeEps.json", tsDnodeDir);
+
+  FILE *fp = fopen(file, "w");
+  if (!fp) {
+    dError("failed to write %s, reason:%s", file, strerror(errno));
+    return -1;
+  }
+
+  int32_t len = 0;
+  int32_t maxLen = 30000;
+  char *  content = calloc(1, maxLen + 1);
+
+  len += snprintf(content + len, maxLen - len, "{\n");
+  len += snprintf(content + len, maxLen - len, "  \"dnodeNum\": %d,\n", tsEps->dnodeNum);
+  len += snprintf(content + len, maxLen - len, "  \"dnodeInfos\": [{\n");
+  for (int32_t i = 0; i < tsEps->dnodeNum; ++i) {
+    SDnodeEp *ep = &tsEps->dnodeEps[i];
+    len += snprintf(content + len, maxLen - len, "    \"dnodeId\": %d,\n", ep->dnodeId);
+    len += snprintf(content + len, maxLen - len, "    \"dnodeFqdn\": \"%s\",\n", ep->dnodeFqdn);
+    len += snprintf(content + len, maxLen - len, "    \"dnodePort\": %u\n", ep->dnodePort);
+    if (i < tsEps->dnodeNum - 1) {
+      len += snprintf(content + len, maxLen - len, "  },{\n");
+    } else {
+      len += snprintf(content + len, maxLen - len, "  }]\n");
+    }
+  }
+  len += snprintf(content + len, maxLen - len, "}\n");
+
+  fwrite(content, 1, len, fp);
+  fflush(fp);
+  fclose(fp);
+  free(content);
+  terrno = 0;
+
+  dInfo("successed to write %s", file);
+  return 0;
+}
diff --git a/src/dnode/src/dnodeMInfos.c b/src/dnode/src/dnodeMInfos.c
new file mode 100644
index 0000000000..c985db371d
--- /dev/null
+++ b/src/dnode/src/dnodeMInfos.c
@@ -0,0 +1,288 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "cJSON.h"
+#include "tglobal.h"
+#include "mnode.h"
+#include "dnode.h"
+#include "dnodeInt.h"
+#include "dnodeMInfos.h"
+
+static SMnodeInfos tsMInfos;
+static SRpcEpSet   tsMEpSet;
+static pthread_mutex_t tsMInfosMutex;
+
+static void    dnodeResetMInfos(SMnodeInfos *minfos);
+static void    dnodePrintMInfos(SMnodeInfos *minfos);
+static int32_t dnodeReadMInfos();
+static int32_t dnodeWriteMInfos();
+
+int32_t dnodeInitMInfos() {
+  pthread_mutex_init(&tsMInfosMutex, NULL);
+  dnodeResetMInfos(NULL);
+  int32_t ret = dnodeReadMInfos();
+  if (ret == 0) {
+    dInfo("dnode minfos is initialized");
+  }
+
+  return ret;
+}
+
+void dnodeCleanupMInfos() { pthread_mutex_destroy(&tsMInfosMutex); }
+
+void dnodeUpdateMInfos(SMnodeInfos *minfos) {
+  if (minfos->mnodeNum <= 0 || minfos->mnodeNum > 3) {
+    dError("invalid mnode infos, mnodeNum:%d", minfos->mnodeNum);
+    return;
+  }
+
+  for (int32_t i = 0; i < minfos->mnodeNum; ++i) {
+    SMnodeInfo *minfo = &minfos->mnodeInfos[i];
+    minfo->mnodeId = htonl(minfo->mnodeId);
+    if (minfo->mnodeId <= 0 || strlen(minfo->mnodeEp) <= 5) {
+      dError("invalid mnode info:%d, mnodeId:%d mnodeEp:%s", i, minfo->mnodeId, minfo->mnodeEp);
+      return;
+    }
+  }
+
+  pthread_mutex_lock(&tsMInfosMutex);
+  if (minfos->mnodeNum != tsMInfos.mnodeNum) {
+    dnodeResetMInfos(minfos);
+    dnodeWriteMInfos();
+    sdbUpdateAsync();
+  } else {
+    int32_t size = sizeof(SMnodeInfos);
+    if (memcmp(minfos, &tsMInfos, size) != 0) {
+      dnodeResetMInfos(minfos);
+      dnodeWriteMInfos();
+      sdbUpdateAsync();
+    }
+  }
+  pthread_mutex_unlock(&tsMInfosMutex);
+}
+
+void dnodeUpdateEpSetForPeer(SRpcEpSet *ep) {
+  if (ep->numOfEps <= 0) {
+    dError("mnode EP list for peer is changed, but content is invalid, discard it");
+    return;
+  }
+
+  pthread_mutex_lock(&tsMInfosMutex);
+  dInfo("mnode EP list for peer is changed, numOfEps:%d inUse:%d", ep->numOfEps, ep->inUse);
+  for (int i = 0; i < ep->numOfEps; ++i) {
+    ep->port[i] -= TSDB_PORT_DNODEDNODE;
+    dInfo("mnode index:%d %s:%u", i, ep->fqdn[i], ep->port[i]);
+  }
+  tsMEpSet = *ep;
+  pthread_mutex_unlock(&tsMInfosMutex);
+}
+
+bool dnodeIsMasterEp(char *ep) {
+  pthread_mutex_lock(&tsMInfosMutex);
+  bool isMaster = strcmp(ep, tsMInfos.mnodeInfos[tsMEpSet.inUse].mnodeEp) == 0;
+  pthread_mutex_unlock(&tsMInfosMutex);
+
+  return isMaster;
+}
+
+void dnodeGetMInfos(SMnodeInfos *minfos) {
+  pthread_mutex_lock(&tsMInfosMutex);
+  memcpy(minfos, &tsMInfos, sizeof(SMnodeInfos));
+  for (int32_t i = 0; i < tsMInfos.mnodeNum; ++i) {
+    minfos->mnodeInfos[i].mnodeId = htonl(tsMInfos.mnodeInfos[i].mnodeId);
+  }
+  pthread_mutex_unlock(&tsMInfosMutex);
+}
+
+void dnodeGetEpSetForPeer(SRpcEpSet *epSet) {
+  pthread_mutex_lock(&tsMInfosMutex);
+  *epSet = tsMEpSet;
+  for (int i = 0; i < epSet->numOfEps; ++i) {
+    epSet->port[i] += TSDB_PORT_DNODEDNODE;
+  }
+  pthread_mutex_unlock(&tsMInfosMutex);
+}
+
+void dnodeGetEpSetForShell(SRpcEpSet *epSet) {
+  pthread_mutex_lock(&tsMInfosMutex);
+  *epSet = tsMEpSet;
+  pthread_mutex_unlock(&tsMInfosMutex);
+}
+
+static void dnodePrintMInfos(SMnodeInfos *minfos) {
+  dInfo("print mnode infos, mnodeNum:%d inUse:%d", minfos->mnodeNum, minfos->inUse);
+  for (int32_t i = 0; i < minfos->mnodeNum; i++) {
+    dInfo("mnode index:%d, %s", minfos->mnodeInfos[i].mnodeId, minfos->mnodeInfos[i].mnodeEp);
+  }
+}
+
+static void dnodeResetMInfos(SMnodeInfos *minfos) {
+  if (minfos == NULL) {
+    tsMEpSet.numOfEps = 1;
+    taosGetFqdnPortFromEp(tsFirst, tsMEpSet.fqdn[0], &tsMEpSet.port[0]);
+
+    if (strcmp(tsSecond, tsFirst) != 0) {
+      tsMEpSet.numOfEps = 2;
+      taosGetFqdnPortFromEp(tsSecond, tsMEpSet.fqdn[1], &tsMEpSet.port[1]);
+    }
+    return;
+  }
+
+  if (minfos->mnodeNum == 0) return;
+
+  int32_t size = sizeof(SMnodeInfos);
+  memcpy(&tsMInfos, minfos, size);
+
+  tsMEpSet.inUse = tsMInfos.inUse;
+  tsMEpSet.numOfEps = tsMInfos.mnodeNum;
+  for (int32_t i = 0; i < tsMInfos.mnodeNum; i++) {
+    taosGetFqdnPortFromEp(tsMInfos.mnodeInfos[i].mnodeEp, tsMEpSet.fqdn[i], &tsMEpSet.port[i]);
+  }
+
+  dnodePrintMInfos(minfos);
+}
+
+static int32_t dnodeReadMInfos() {
+  int32_t     len = 0;
+  int32_t     maxLen = 2000;
+  char *      content = calloc(1, maxLen + 1);
+  cJSON *     root = NULL;
+  FILE *      fp = NULL;
+  SMnodeInfos minfos = {0};
+
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/mnodeEpSet.json", tsDnodeDir);
+
+  fp = fopen(file, "r");
+  if (!fp) {
+    dDebug("failed to read %s, file not exist", file);
+    goto PARSE_MINFOS_OVER;
+  }
+
+  len = fread(content, 1, maxLen, fp);
+  if (len <= 0) {
+    dError("failed to read %s, content is null", file);
+    goto PARSE_MINFOS_OVER;
+  }
+
+  content[len] = 0;
+  root = cJSON_Parse(content);
+  if (root == NULL) {
+    dError("failed to read %s, invalid json format", file);
+    goto PARSE_MINFOS_OVER;
+  }
+
+  cJSON *inUse = cJSON_GetObjectItem(root, "inUse");
+  if (!inUse || inUse->type != cJSON_Number) {
+    dError("failed to read mnodeEpSet.json, inUse not found");
+    goto PARSE_MINFOS_OVER;
+  }
+  tsMInfos.inUse = inUse->valueint;
+
+  cJSON *nodeNum = cJSON_GetObjectItem(root, "nodeNum");
+  if (!nodeNum || nodeNum->type != cJSON_Number) {
+    dError("failed to read mnodeEpSet.json, nodeNum not found");
+    goto PARSE_MINFOS_OVER;
+  }
+  minfos.mnodeNum = nodeNum->valueint;
+
+  cJSON *nodeInfos = cJSON_GetObjectItem(root, "nodeInfos");
+  if (!nodeInfos || nodeInfos->type != cJSON_Array) {
+    dError("failed to read mnodeEpSet.json, nodeInfos not found");
+    goto PARSE_MINFOS_OVER;
+  }
+
+  int size = cJSON_GetArraySize(nodeInfos);
+  if (size != minfos.mnodeNum) {
+    dError("failed to read mnodeEpSet.json, nodeInfos size not matched");
+    goto PARSE_MINFOS_OVER;
+  }
+
+  for (int i = 0; i < size; ++i) {
+    cJSON *nodeInfo = cJSON_GetArrayItem(nodeInfos, i);
+    if (nodeInfo == NULL) continue;
+
+    cJSON *nodeId = cJSON_GetObjectItem(nodeInfo, "nodeId");
+    if (!nodeId || nodeId->type != cJSON_Number) {
+      dError("failed to read mnodeEpSet.json, nodeId not found");
+      goto PARSE_MINFOS_OVER;
+    }
+    minfos.mnodeInfos[i].mnodeId = nodeId->valueint;
+
+    cJSON *nodeEp = cJSON_GetObjectItem(nodeInfo, "nodeEp");
+    if (!nodeEp || nodeEp->type != cJSON_String || nodeEp->valuestring == NULL) {
+      dError("failed to read mnodeEpSet.json, nodeName not found");
+      goto PARSE_MINFOS_OVER;
+    }
+    strncpy(minfos.mnodeInfos[i].mnodeEp, nodeEp->valuestring, TSDB_EP_LEN);
+  }
+
+  dInfo("read file %s successed", file);
+  dnodePrintMInfos(&minfos);
+
+PARSE_MINFOS_OVER:
+  if (content != NULL) free(content);
+  if (root != NULL) cJSON_Delete(root);
+  if (fp != NULL) fclose(fp);
+  terrno = 0;
+
+  for (int32_t i = 0; i < minfos.mnodeNum; ++i) {
+    SMnodeInfo *mInfo = &minfos.mnodeInfos[i];
+    dnodeUpdateEp(mInfo->mnodeId, mInfo->mnodeEp, NULL, NULL);
+  }
+  dnodeResetMInfos(&minfos);
+  return 0;
+}
+
+static int32_t dnodeWriteMInfos() {
+  char file[TSDB_FILENAME_LEN + 20] = {0};
+  sprintf(file, "%s/mnodeEpSet.json", tsDnodeDir);
+
+  FILE *fp = fopen(file, "w");
+  if (!fp) {
+    dError("failed to write %s, reason:%s", file, strerror(errno));
+    return -1;
+  }
+
+  int32_t len = 0;
+  int32_t maxLen = 2000;
+  char *  content = calloc(1, maxLen + 1);
+
+  len += snprintf(content + len, maxLen - len, "{\n");
+  len += snprintf(content + len, maxLen - len, "  \"inUse\": %d,\n", tsMInfos.inUse);
+  len += snprintf(content + len, maxLen - len, "  \"nodeNum\": %d,\n", tsMInfos.mnodeNum);
+  len += snprintf(content + len, maxLen - len, "  \"nodeInfos\": [{\n");
+  for (int32_t i = 0; i < tsMInfos.mnodeNum; i++) {
+    len += snprintf(content + len, maxLen - len, "    \"nodeId\": %d,\n", tsMInfos.mnodeInfos[i].mnodeId);
+    len += snprintf(content + len, maxLen - len, "    \"nodeEp\": \"%s\"\n", tsMInfos.mnodeInfos[i].mnodeEp);
+    if (i < tsMInfos.mnodeNum - 1) {
+      len += snprintf(content + len, maxLen - len, "  },{\n");
+    } else {
+      len += snprintf(content + len, maxLen - len, "  }]\n");
+    }
+  }
+  len += snprintf(content + len, maxLen - len, "}\n");
+
+  fwrite(content, 1, len, fp);
+  fflush(fp);
+  fclose(fp);
+  free(content);
+  terrno = 0;
+
+  dInfo("successed to write %s", file);
+  return 0;
+}
diff --git a/src/dnode/src/dnodeMPeer.c b/src/dnode/src/dnodeMPeer.c
index 8414d79a98..0da7ab74e4 100644
--- a/src/dnode/src/dnodeMPeer.c
+++ b/src/dnode/src/dnodeMPeer.c
@@ -58,7 +58,7 @@ int32_t dnodeInitMnodePeer() {
     dDebug("dnode mpeer worker:%d is created", i);
   }
 
-  dDebug("dnode mpeer is opened, workers:%d qset:%p", tsMPeerPool.maxNum, tsMPeerQset);
+  dDebug("dnode mpeer is initialized, workers:%d qset:%p", tsMPeerPool.maxNum, tsMPeerQset);
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeMRead.c b/src/dnode/src/dnodeMRead.c
index fdcbb5889f..4ad787f26e 100644
--- a/src/dnode/src/dnodeMRead.c
+++ b/src/dnode/src/dnodeMRead.c
@@ -60,7 +60,7 @@ int32_t dnodeInitMnodeRead() {
     dDebug("dnode mread worker:%d is created", i);
   }
 
-  dDebug("dnode mread is opened, workers:%d qset:%p", tsMReadPool.maxNum, tsMReadQset);
+  dDebug("dnode mread is initialized, workers:%d qset:%p", tsMReadPool.maxNum, tsMReadQset);
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeMWrite.c b/src/dnode/src/dnodeMWrite.c
index 384a0fae75..600688b9fd 100644
--- a/src/dnode/src/dnodeMWrite.c
+++ b/src/dnode/src/dnodeMWrite.c
@@ -60,7 +60,7 @@ int32_t dnodeInitMnodeWrite() {
     dDebug("dnode mwrite worker:%d is created", i);
   }
 
-  dDebug("dnode mwrite is opened, workers:%d qset:%p", tsMWritePool.maxNum, tsMWriteQset);
+  dDebug("dnode mwrite is initialized, workers:%d qset:%p", tsMWritePool.maxNum, tsMWriteQset);
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeMain.c b/src/dnode/src/dnodeMain.c
index 97e6f2ce6d..c9cb59150c 100644
--- a/src/dnode/src/dnodeMain.c
+++ b/src/dnode/src/dnodeMain.c
@@ -19,11 +19,15 @@
 #include "tutil.h"
 #include "tconfig.h"
 #include "tglobal.h"
+#include "twal.h"
 #include "dnode.h"
 #include "dnodeInt.h"
 #include "dnodeMgmt.h"
 #include "dnodePeer.h"
 #include "dnodeModule.h"
+#include "dnodeEps.h"
+#include "dnodeMInfos.h"
+#include "dnodeCfg.h"
 #include "dnodeCheck.h"
 #include "dnodeVRead.h"
 #include "dnodeVWrite.h"
@@ -33,23 +37,29 @@
 #include "dnodeShell.h"
 #include "dnodeTelemetry.h"
 
-static int32_t dnodeInitStorage();
-static void dnodeCleanupStorage();
-static void dnodeSetRunStatus(SDnodeRunStatus status);
-static void dnodeCheckDataDirOpenned(char *dir);
 static SDnodeRunStatus tsDnodeRunStatus = TSDB_DNODE_RUN_STATUS_STOPPED;
+
+static int32_t dnodeInitStorage();
+static void    dnodeCleanupStorage();
+static void    dnodeSetRunStatus(SDnodeRunStatus status);
+static void    dnodeCheckDataDirOpenned(char *dir);
 static int32_t dnodeInitComponents();
-static void dnodeCleanupComponents(int32_t stepId);
-static int dnodeCreateDir(const char *dir);
+static void    dnodeCleanupComponents(int32_t stepId);
+static int     dnodeCreateDir(const char *dir);
 
 typedef struct {
   const char *const name;
-  int               (*init)();
-  void              (*cleanup)();
+  int32_t (*init)();
+  void (*cleanup)();
 } SDnodeComponent;
 
 static const SDnodeComponent tsDnodeComponents[] = {
   {"storage",   dnodeInitStorage,    dnodeCleanupStorage},
+  {"dnodecfg",  dnodeInitCfg,        dnodeCleanupCfg},
+  {"dnodeeps",  dnodeInitEps,        dnodeCleanupEps},
+  {"globalcfg" ,taosCheckGlobalCfg,  NULL},
+  {"mnodeinfos",dnodeInitMInfos,     dnodeCleanupMInfos},
+  {"wal",       walInit,             walCleanUp},
   {"check",     dnodeInitCheck,      dnodeCleanupCheck},     // NOTES: dnodeInitCheck must be behind the dnodeinitStorage component !!!
   {"vread",     dnodeInitVnodeRead,  dnodeCleanupVnodeRead},
   {"vwrite",    dnodeInitVnodeWrite, dnodeCleanupVnodeWrite},
@@ -75,7 +85,9 @@ static int dnodeCreateDir(const char *dir) {
 
 static void dnodeCleanupComponents(int32_t stepId) {
   for (int32_t i = stepId; i >= 0; i--) {
-    tsDnodeComponents[i].cleanup();
+    if (tsDnodeComponents[i].cleanup) {
+      (*tsDnodeComponents[i].cleanup)();
+    }
   }
 }
 
@@ -112,14 +124,13 @@ int32_t dnodeInitSystem() {
     printf("failed to init log file\n");
   }
 
-  if (!taosReadGlobalCfg() || !taosCheckGlobalCfg()) {
+  if (!taosReadGlobalCfg()) {
     taosPrintGlobalCfg();
     dError("TDengine read global config failed");
     return -1;
   }
-  taosPrintGlobalCfg();
 
-  dInfo("start to initialize TDengine on %s", tsLocalEp);
+  dInfo("start to initialize TDengine");
 
   if (dnodeInitComponents() != 0) {
     return -1;
@@ -198,7 +209,7 @@ static int32_t dnodeInitStorage() {
 
   dnodeCheckDataDirOpenned(tsDnodeDir);
 
-  dInfo("storage directory is initialized");
+  dInfo("dnode storage is initialized at %s", tsDnodeDir);
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeMgmt.c b/src/dnode/src/dnodeMgmt.c
index 968a8d9759..4a5dc31a9f 100644
--- a/src/dnode/src/dnodeMgmt.c
+++ b/src/dnode/src/dnodeMgmt.c
@@ -31,12 +31,13 @@
 #include "mnode.h"
 #include "dnodeInt.h"
 #include "dnodeMgmt.h"
+#include "dnodeEps.h"
+#include "dnodeCfg.h"
+#include "dnodeMInfos.h"
 #include "dnodeVRead.h"
 #include "dnodeVWrite.h"
 #include "dnodeModule.h"
 
-#define MPEER_CONTENT_LEN 2000
-
 typedef struct {
   pthread_t thread;
   int32_t   threadIndex;
@@ -46,23 +47,13 @@ typedef struct {
   int32_t * vnodeList;
 } SOpenVnodeThread;
 
-void *          tsDnodeTmr = NULL;
-static void *   tsStatusTimer = NULL;
-static uint32_t tsRebootTime;
+void *            tsDnodeTmr = NULL;
+static void *     tsStatusTimer = NULL;
+static uint32_t   tsRebootTime;
+static taos_qset  tsMgmtQset = NULL;
+static taos_queue tsMgmtQueue = NULL;
+static pthread_t  tsQthread;
 
-static SRpcEpSet     tsDMnodeEpSet = {0};
-static SDMMnodeInfos tsDMnodeInfos = {0};
-static SDMDnodeCfg   tsDnodeCfg = {0};
-static taos_qset     tsMgmtQset = NULL;
-static taos_queue    tsMgmtQueue = NULL;
-static pthread_t     tsQthread;
-
-static void   dnodeUpdateMnodeInfos(SDMMnodeInfos *pMnodes);
-static bool   dnodeReadMnodeInfos();
-static void   dnodeSaveMnodeInfos();
-static void   dnodeUpdateDnodeCfg(SDMDnodeCfg *pCfg);
-static bool   dnodeReadDnodeCfg();
-static void   dnodeSaveDnodeCfg();
 static void   dnodeProcessStatusRsp(SRpcMsg *pMsg);
 static void   dnodeSendStatusMsg(void *handle, void *tmrId);
 static void  *dnodeProcessMgmtQueue(void *param);
@@ -74,7 +65,7 @@ static int32_t  dnodeProcessAlterVnodeMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessDropVnodeMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessAlterStreamMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessConfigDnodeMsg(SRpcMsg *pMsg);
-static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg);
+static int32_t  dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg);
 static int32_t (*dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MAX])(SRpcMsg *pMsg);
 
 int32_t dnodeInitMgmt() {
@@ -86,28 +77,8 @@ int32_t dnodeInitMgmt() {
   dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_CREATE_MNODE] = dnodeProcessCreateMnodeMsg;
 
   dnodeAddClientRspHandle(TSDB_MSG_TYPE_DM_STATUS_RSP,  dnodeProcessStatusRsp);
-  dnodeReadDnodeCfg();
   tsRebootTime = taosGetTimestampSec();
 
-  if (!dnodeReadMnodeInfos()) {
-    memset(&tsDMnodeEpSet, 0, sizeof(SRpcEpSet));
-    memset(&tsDMnodeInfos, 0, sizeof(SDMMnodeInfos));
-
-    tsDMnodeEpSet.numOfEps = 1;
-    taosGetFqdnPortFromEp(tsFirst, tsDMnodeEpSet.fqdn[0], &tsDMnodeEpSet.port[0]);
-    
-    if (strcmp(tsSecond, tsFirst) != 0) {
-      tsDMnodeEpSet.numOfEps = 2;
-      taosGetFqdnPortFromEp(tsSecond, tsDMnodeEpSet.fqdn[1], &tsDMnodeEpSet.port[1]);
-    }
-  } else {
-    tsDMnodeEpSet.inUse = tsDMnodeInfos.inUse;
-    tsDMnodeEpSet.numOfEps = tsDMnodeInfos.nodeNum;
-    for (int32_t i = 0; i < tsDMnodeInfos.nodeNum; i++) {
-      taosGetFqdnPortFromEp(tsDMnodeInfos.nodeInfos[i].nodeEp, tsDMnodeEpSet.fqdn[i], &tsDMnodeEpSet.port[i]);
-    }
-  }
-
   int32_t code = vnodeInitResources();
   if (code != TSDB_CODE_SUCCESS) {
     dnodeCleanupMgmt();
@@ -381,7 +352,7 @@ static void dnodeCloseVnodes() {
 }
 
 static void* dnodeParseVnodeMsg(SRpcMsg *rpcMsg) {
-  SMDCreateVnodeMsg *pCreate = rpcMsg->pCont;
+  SCreateVnodeMsg *pCreate = rpcMsg->pCont;
   pCreate->cfg.vgId                = htonl(pCreate->cfg.vgId);
   pCreate->cfg.cfgVersion          = htonl(pCreate->cfg.cfgVersion);
   pCreate->cfg.maxTables           = htonl(pCreate->cfg.maxTables);
@@ -404,7 +375,7 @@ static void* dnodeParseVnodeMsg(SRpcMsg *rpcMsg) {
 }
 
 static int32_t dnodeProcessCreateVnodeMsg(SRpcMsg *rpcMsg) {
-  SMDCreateVnodeMsg *pCreate = dnodeParseVnodeMsg(rpcMsg);
+  SCreateVnodeMsg *pCreate = dnodeParseVnodeMsg(rpcMsg);
 
   void *pVnode = vnodeAcquire(pCreate->cfg.vgId);
   if (pVnode != NULL) {
@@ -418,7 +389,7 @@ static int32_t dnodeProcessCreateVnodeMsg(SRpcMsg *rpcMsg) {
 }
 
 static int32_t dnodeProcessAlterVnodeMsg(SRpcMsg *rpcMsg) {
-  SMDAlterVnodeMsg *pAlter = dnodeParseVnodeMsg(rpcMsg);
+  SAlterVnodeMsg *pAlter = dnodeParseVnodeMsg(rpcMsg);
 
   void *pVnode = vnodeAcquire(pAlter->cfg.vgId);
   if (pVnode != NULL) {
@@ -433,14 +404,14 @@ static int32_t dnodeProcessAlterVnodeMsg(SRpcMsg *rpcMsg) {
 }
 
 static int32_t dnodeProcessDropVnodeMsg(SRpcMsg *rpcMsg) {
-  SMDDropVnodeMsg *pDrop = rpcMsg->pCont;
+  SDropVnodeMsg *pDrop = rpcMsg->pCont;
   pDrop->vgId = htonl(pDrop->vgId);
 
   return vnodeDrop(pDrop->vgId);
 }
 
 static int32_t dnodeProcessAlterStreamMsg(SRpcMsg *pMsg) {
-//  SMDAlterStreamMsg *pStream = pCont;
+//  SAlterStreamMsg *pStream = pCont;
 //  pStream->uid    = htobe64(pStream->uid);
 //  pStream->stime  = htobe64(pStream->stime);
 //  pStream->vnode  = htonl(pStream->vnode);
@@ -453,12 +424,12 @@ static int32_t dnodeProcessAlterStreamMsg(SRpcMsg *pMsg) {
 }
 
 static int32_t dnodeProcessConfigDnodeMsg(SRpcMsg *pMsg) {
-  SMDCfgDnodeMsg *pCfg = pMsg->pCont;
+  SCfgDnodeMsg *pCfg = pMsg->pCont;
   return taosCfgDynamicOptions(pCfg->config);
 }
 
 static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg) {
-  SMDCreateMnodeMsg *pCfg = pMsg->pCont;
+  SCreateMnodeMsg *pCfg = pMsg->pCont;
   pCfg->dnodeId = htonl(pCfg->dnodeId);
   if (pCfg->dnodeId != dnodeGetDnodeId()) {
     dError("dnodeId:%d, in create mnode msg is not equal with saved dnodeId:%d", pCfg->dnodeId, dnodeGetDnodeId());
@@ -470,10 +441,10 @@ static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg) {
     return TSDB_CODE_MND_DNODE_EP_NOT_CONFIGURED;
   }
 
-  dDebug("dnodeId:%d, create mnode msg is received from mnodes, numOfMnodes:%d", pCfg->dnodeId, pCfg->mnodes.nodeNum);
-  for (int i = 0; i < pCfg->mnodes.nodeNum; ++i) {
-    pCfg->mnodes.nodeInfos[i].nodeId = htonl(pCfg->mnodes.nodeInfos[i].nodeId);
-    dDebug("mnode index:%d, mnode:%d:%s", i, pCfg->mnodes.nodeInfos[i].nodeId, pCfg->mnodes.nodeInfos[i].nodeEp);
+  dDebug("dnodeId:%d, create mnode msg is received from mnodes, numOfMnodes:%d", pCfg->dnodeId, pCfg->mnodes.mnodeNum);
+  for (int i = 0; i < pCfg->mnodes.mnodeNum; ++i) {
+    pCfg->mnodes.mnodeInfos[i].mnodeId = htonl(pCfg->mnodes.mnodeInfos[i].mnodeId);
+    dDebug("mnode index:%d, mnode:%d:%s", i, pCfg->mnodes.mnodeInfos[i].mnodeId, pCfg->mnodes.mnodeInfos[i].mnodeEp);
   }
 
   dnodeStartMnode(&pCfg->mnodes);
@@ -481,34 +452,6 @@ static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg) {
   return TSDB_CODE_SUCCESS;
 }
 
-void dnodeUpdateMnodeEpSetForPeer(SRpcEpSet *pEpSet) {
-  if (pEpSet->numOfEps <= 0) {
-    dError("mnode EP list for peer is changed, but content is invalid, discard it");
-    return;
-  }
-
-  dInfo("mnode EP list for peer is changed, numOfEps:%d inUse:%d", pEpSet->numOfEps, pEpSet->inUse);
-  for (int i = 0; i < pEpSet->numOfEps; ++i) {
-    pEpSet->port[i] -= TSDB_PORT_DNODEDNODE;
-    dInfo("mnode index:%d %s:%u", i, pEpSet->fqdn[i], pEpSet->port[i]);
-  }
-
-  tsDMnodeEpSet = *pEpSet;
-}
-
-void dnodeGetMnodeEpSetForPeer(void *epSetRaw) {
-  SRpcEpSet *epSet = epSetRaw;
-  *epSet = tsDMnodeEpSet;
-
-  for (int i=0; i<epSet->numOfEps; ++i) 
-    epSet->port[i] += TSDB_PORT_DNODEDNODE;
-}
-
-void dnodeGetMnodeEpSetForShell(void *epSetRaw) {
-  SRpcEpSet *epSet = epSetRaw;
-  *epSet = tsDMnodeEpSet;
-}
-
 static void dnodeProcessStatusRsp(SRpcMsg *pMsg) {
   if (pMsg->code != TSDB_CODE_SUCCESS) {
     dError("status rsp is received, error:%s", tstrerror(pMsg->code));
@@ -516,202 +459,24 @@ static void dnodeProcessStatusRsp(SRpcMsg *pMsg) {
     return;
   }
 
-  SDMStatusRsp *pStatusRsp = pMsg->pCont;
-  SDMMnodeInfos *pMnodes = &pStatusRsp->mnodes;
-  if (pMnodes->nodeNum <= 0) {
-    dError("status msg is invalid, num of ips is %d", pMnodes->nodeNum);
-    taosTmrReset(dnodeSendStatusMsg, tsStatusInterval * 1000, NULL, tsDnodeTmr, &tsStatusTimer);
-    return;
-  }
+  SStatusRsp *pStatusRsp = pMsg->pCont;
+  SMnodeInfos *minfos = &pStatusRsp->mnodes;
+  dnodeUpdateMInfos(minfos);
 
-  SDMDnodeCfg *pCfg = &pStatusRsp->dnodeCfg;
-  pCfg->numOfVnodes  = htonl(pCfg->numOfVnodes);
+  SDnodeCfg *pCfg = &pStatusRsp->dnodeCfg;
+  pCfg->numOfVnodes = htonl(pCfg->numOfVnodes);
   pCfg->moduleStatus = htonl(pCfg->moduleStatus);
   pCfg->dnodeId = htonl(pCfg->dnodeId);
-
-  for (int32_t i = 0; i < pMnodes->nodeNum; ++i) {
-    SDMMnodeInfo *pMnodeInfo = &pMnodes->nodeInfos[i];
-    pMnodeInfo->nodeId   = htonl(pMnodeInfo->nodeId);
-  }
+  dnodeUpdateCfg(pCfg);
 
   vnodeSetAccess(pStatusRsp->vgAccess, pCfg->numOfVnodes);
 
-  // will not set mnode in status msg
-  // dnodeProcessModuleStatus(pCfg->moduleStatus);
-  dnodeUpdateDnodeCfg(pCfg);
+  SDnodeEps *pEps = (SDnodeEps *)((char *)pStatusRsp->vgAccess + pCfg->numOfVnodes * sizeof(SVgroupAccess));
+  dnodeUpdateEps(pEps);
 
-  dnodeUpdateMnodeInfos(pMnodes);
   taosTmrReset(dnodeSendStatusMsg, tsStatusInterval * 1000, NULL, tsDnodeTmr, &tsStatusTimer);
 }
 
-static bool dnodeCheckMnodeInfos(SDMMnodeInfos *pMnodes) {
-  if (pMnodes->nodeNum <= 0 || pMnodes->nodeNum > 3) {
-    dError("invalid mnode infos, num:%d", pMnodes->nodeNum);
-    return false;
-  }
-
-  for (int32_t i = 0; i < pMnodes->nodeNum; ++i) {
-    SDMMnodeInfo *pMnodeInfo = &pMnodes->nodeInfos[i];
-    if (pMnodeInfo->nodeId <= 0 || strlen(pMnodeInfo->nodeEp) <= 5) {
-      dError("invalid mnode info:%d, nodeId:%d nodeEp:%s", i, pMnodeInfo->nodeId, pMnodeInfo->nodeEp);
-      return false;
-    }
-  }
-
-  return true;
-}
-
-static void dnodeUpdateMnodeInfos(SDMMnodeInfos *pMnodes) {
-  bool mnodesChanged = (memcmp(&tsDMnodeInfos, pMnodes, sizeof(SDMMnodeInfos)) != 0);
-  bool mnodesNotInit = (tsDMnodeInfos.nodeNum == 0);
-  if (!(mnodesChanged || mnodesNotInit)) return;
-
-  if (!dnodeCheckMnodeInfos(pMnodes)) return;
-
-  memcpy(&tsDMnodeInfos, pMnodes, sizeof(SDMMnodeInfos));
-  dInfo("mnode infos is changed, nodeNum:%d inUse:%d", tsDMnodeInfos.nodeNum, tsDMnodeInfos.inUse);
-  for (int32_t i = 0; i < tsDMnodeInfos.nodeNum; i++) {
-    dInfo("mnode index:%d, %s", tsDMnodeInfos.nodeInfos[i].nodeId, tsDMnodeInfos.nodeInfos[i].nodeEp);
-  }
-
-  tsDMnodeEpSet.inUse = tsDMnodeInfos.inUse;
-  tsDMnodeEpSet.numOfEps = tsDMnodeInfos.nodeNum;
-  for (int32_t i = 0; i < tsDMnodeInfos.nodeNum; i++) {
-    taosGetFqdnPortFromEp(tsDMnodeInfos.nodeInfos[i].nodeEp, tsDMnodeEpSet.fqdn[i], &tsDMnodeEpSet.port[i]);
-  }
-
-  dnodeSaveMnodeInfos();
-  sdbUpdateAsync();
-}
-
-static bool dnodeReadMnodeInfos() {
-  char ipFile[TSDB_FILENAME_LEN*2] = {0};
-  
-  sprintf(ipFile, "%s/mnodeEpSet.json", tsDnodeDir);
-  FILE *fp = fopen(ipFile, "r");
-  if (!fp) {
-    dDebug("failed to read mnodeEpSet.json, file not exist");
-    return false;
-  }
-
-  bool  ret = false;
-  int   maxLen = 2000;
-  char *content = calloc(1, maxLen + 1);
-  int   len = fread(content, 1, maxLen, fp);
-  if (len <= 0) {
-    free(content);
-    fclose(fp);
-    dError("failed to read mnodeEpSet.json, content is null");
-    return false;
-  }
-
-  content[len] = 0;
-  cJSON* root = cJSON_Parse(content);
-  if (root == NULL) {
-    dError("failed to read mnodeEpSet.json, invalid json format");
-    goto PARSE_OVER;
-  }
-
-  cJSON* inUse = cJSON_GetObjectItem(root, "inUse");
-  if (!inUse || inUse->type != cJSON_Number) {
-    dError("failed to read mnodeEpSet.json, inUse not found");
-    goto PARSE_OVER;
-  }
-  tsDMnodeInfos.inUse = inUse->valueint;
-
-  cJSON* nodeNum = cJSON_GetObjectItem(root, "nodeNum");
-  if (!nodeNum || nodeNum->type != cJSON_Number) {
-    dError("failed to read mnodeEpSet.json, nodeNum not found");
-    goto PARSE_OVER;
-  }
-  tsDMnodeInfos.nodeNum = nodeNum->valueint;
-
-  cJSON* nodeInfos = cJSON_GetObjectItem(root, "nodeInfos");
-  if (!nodeInfos || nodeInfos->type != cJSON_Array) {
-    dError("failed to read mnodeEpSet.json, nodeInfos not found");
-    goto PARSE_OVER;
-  }
-
-  int size = cJSON_GetArraySize(nodeInfos);
-  if (size != tsDMnodeInfos.nodeNum) {
-    dError("failed to read mnodeEpSet.json, nodeInfos size not matched");
-    goto PARSE_OVER;
-  }
-
-  for (int i = 0; i < size; ++i) {
-    cJSON *nodeInfo = cJSON_GetArrayItem(nodeInfos, i);
-    if (nodeInfo == NULL) continue;
-
-    cJSON *nodeId = cJSON_GetObjectItem(nodeInfo, "nodeId");
-    if (!nodeId || nodeId->type != cJSON_Number) {
-      dError("failed to read mnodeEpSet.json, nodeId not found");
-      goto PARSE_OVER;
-    }
-    tsDMnodeInfos.nodeInfos[i].nodeId = nodeId->valueint;
-
-    cJSON *nodeEp = cJSON_GetObjectItem(nodeInfo, "nodeEp");
-    if (!nodeEp || nodeEp->type != cJSON_String || nodeEp->valuestring == NULL) {
-      dError("failed to read mnodeEpSet.json, nodeName not found");
-      goto PARSE_OVER;
-    }
-    strncpy(tsDMnodeInfos.nodeInfos[i].nodeEp, nodeEp->valuestring, TSDB_EP_LEN);
-  }
-
-  ret = true;
-
-  dInfo("read mnode epSet successed, numOfEps:%d inUse:%d", tsDMnodeInfos.nodeNum, tsDMnodeInfos.inUse);
-  for (int32_t i = 0; i < tsDMnodeInfos.nodeNum; i++) {
-    dInfo("mnode:%d, %s", tsDMnodeInfos.nodeInfos[i].nodeId, tsDMnodeInfos.nodeInfos[i].nodeEp);
-  }
-
-PARSE_OVER:
-  free(content);
-  cJSON_Delete(root);
-  fclose(fp);
-  return ret;
-}
-
-static void dnodeSaveMnodeInfos() {
-  char ipFile[TSDB_FILENAME_LEN] = {0};
-  sprintf(ipFile, "%s/mnodeEpSet.json", tsDnodeDir);
-  FILE *fp = fopen(ipFile, "w");
-  if (!fp) return;
-
-  int32_t len = 0;
-  int32_t maxLen = 2000;
-  char *  content = calloc(1, maxLen + 1);
-
-  len += snprintf(content + len, maxLen - len, "{\n");
-  len += snprintf(content + len, maxLen - len, "  \"inUse\": %d,\n", tsDMnodeInfos.inUse);
-  len += snprintf(content + len, maxLen - len, "  \"nodeNum\": %d,\n", tsDMnodeInfos.nodeNum);
-  len += snprintf(content + len, maxLen - len, "  \"nodeInfos\": [{\n");
-  for (int32_t i = 0; i < tsDMnodeInfos.nodeNum; i++) {
-    len += snprintf(content + len, maxLen - len, "    \"nodeId\": %d,\n", tsDMnodeInfos.nodeInfos[i].nodeId);
-    len += snprintf(content + len, maxLen - len, "    \"nodeEp\": \"%s\"\n", tsDMnodeInfos.nodeInfos[i].nodeEp);
-    if (i < tsDMnodeInfos.nodeNum -1) {
-      len += snprintf(content + len, maxLen - len, "  },{\n");  
-    } else {
-      len += snprintf(content + len, maxLen - len, "  }]\n");  
-    }
-  }
-  len += snprintf(content + len, maxLen - len, "}\n"); 
-
-  fwrite(content, 1, len, fp);
-  fflush(fp);
-  fclose(fp);
-  free(content);
-  
-  dInfo("save mnode epSet successed");
-}
-
-char *dnodeGetMnodeMasterEp() {
-  return tsDMnodeInfos.nodeInfos[tsDMnodeEpSet.inUse].nodeEp;
-}
-
-void* dnodeGetMnodeInfos() {
-  return &tsDMnodeInfos;
-}
-
 static void dnodeSendStatusMsg(void *handle, void *tmrId) {
   if (tsDnodeTmr == NULL) {
     dError("dnode timer is already released");
@@ -724,22 +489,21 @@ static void dnodeSendStatusMsg(void *handle, void *tmrId) {
     return;
   }
 
-  int32_t contLen = sizeof(SDMStatusMsg) + TSDB_MAX_VNODES * sizeof(SVnodeLoad);
-  SDMStatusMsg *pStatus = rpcMallocCont(contLen);
+  int32_t contLen = sizeof(SStatusMsg) + TSDB_MAX_VNODES * sizeof(SVnodeLoad);
+  SStatusMsg *pStatus = rpcMallocCont(contLen);
   if (pStatus == NULL) {
     taosTmrReset(dnodeSendStatusMsg, tsStatusInterval * 1000, NULL, tsDnodeTmr, &tsStatusTimer);
     dError("failed to malloc status message");
     return;
   }
 
-  //strcpy(pStatus->dnodeName, tsDnodeName);
+  dnodeGetCfg(&pStatus->dnodeId, pStatus->clusterId);
+  pStatus->dnodeId          = htonl(dnodeGetDnodeId());
   pStatus->version          = htonl(tsVersion);
-  pStatus->dnodeId          = htonl(tsDnodeCfg.dnodeId);
   pStatus->lastReboot       = htonl(tsRebootTime);
   pStatus->numOfCores       = htons((uint16_t) tsNumOfCores);
   pStatus->diskAvailable    = tsAvailDataDirGB;
   pStatus->alternativeRole  = (uint8_t) tsAlternativeRole;
-  tstrncpy(pStatus->clusterId, tsDnodeCfg.clusterId, TSDB_CLUSTER_ID_LEN);
   tstrncpy(pStatus->dnodeEp, tsLocalEp, TSDB_EP_LEN);
 
   // fill cluster cfg parameters
@@ -759,7 +523,7 @@ static void dnodeSendStatusMsg(void *handle, void *tmrId) {
   tstrncpy(pStatus->clusterCfg.charset, tsCharset, TSDB_LOCALE_LEN);  
   
   vnodeBuildStatusMsg(pStatus);
-  contLen = sizeof(SDMStatusMsg) + pStatus->openVnodes * sizeof(SVnodeLoad);
+  contLen = sizeof(SStatusMsg) + pStatus->openVnodes * sizeof(SVnodeLoad);
   pStatus->openVnodes = htons(pStatus->openVnodes);
   
   SRpcMsg rpcMsg = {
@@ -769,110 +533,19 @@ static void dnodeSendStatusMsg(void *handle, void *tmrId) {
   };
 
   SRpcEpSet epSet;
-  dnodeGetMnodeEpSetForPeer(&epSet);
+  dnodeGetEpSetForPeer(&epSet);
   dnodeSendMsgToDnode(&epSet, &rpcMsg);
 }
 
-static bool dnodeReadDnodeCfg() {
-  char dnodeCfgFile[TSDB_FILENAME_LEN*2] = {0};
-  
-  sprintf(dnodeCfgFile, "%s/dnodeCfg.json", tsDnodeDir);
-
-  FILE *fp = fopen(dnodeCfgFile, "r");
-  if (!fp) {
-    dDebug("failed to read dnodeCfg.json, file not exist");
-    return false;
-  }
-
-  bool  ret = false;
-  int   maxLen = 100;
-  char *content = calloc(1, maxLen + 1);
-  int   len = fread(content, 1, maxLen, fp);
-  if (len <= 0) {
-    free(content);
-    fclose(fp);
-    dError("failed to read dnodeCfg.json, content is null");
-    return false;
-  }
-
-  content[len] = 0;
-  cJSON* root = cJSON_Parse(content);
-  if (root == NULL) {
-    dError("failed to read dnodeCfg.json, invalid json format");
-    goto PARSE_CFG_OVER;
-  }
-
-  cJSON* dnodeId = cJSON_GetObjectItem(root, "dnodeId");
-  if (!dnodeId || dnodeId->type != cJSON_Number) {
-    dError("failed to read dnodeCfg.json, dnodeId not found");
-    goto PARSE_CFG_OVER;
-  }
-  tsDnodeCfg.dnodeId = dnodeId->valueint;
-
-  cJSON* clusterId = cJSON_GetObjectItem(root, "clusterId");
-  if (!clusterId || clusterId->type != cJSON_String) {
-    dError("failed to read dnodeCfg.json, clusterId not found");
-    goto PARSE_CFG_OVER;
-  }
-  tstrncpy(tsDnodeCfg.clusterId, clusterId->valuestring, TSDB_CLUSTER_ID_LEN);
-
-  ret = true;
-
-  dInfo("read numOfVnodes successed, dnodeId:%d", tsDnodeCfg.dnodeId);
-
-PARSE_CFG_OVER:
-  free(content);
-  cJSON_Delete(root);
-  fclose(fp);
-  return ret;
-}
-
-static void dnodeSaveDnodeCfg() {
-  char dnodeCfgFile[TSDB_FILENAME_LEN] = {0};
-  sprintf(dnodeCfgFile, "%s/dnodeCfg.json", tsDnodeDir);
-
-  FILE *fp = fopen(dnodeCfgFile, "w");
-  if (!fp) return;
-
-  int32_t len = 0;
-  int32_t maxLen = 200;
-  char *  content = calloc(1, maxLen + 1);
-
-  len += snprintf(content + len, maxLen - len, "{\n");
-  len += snprintf(content + len, maxLen - len, "  \"dnodeId\": %d,\n", tsDnodeCfg.dnodeId);
-  len += snprintf(content + len, maxLen - len, "  \"clusterId\": \"%s\"\n", tsDnodeCfg.clusterId);
-  len += snprintf(content + len, maxLen - len, "}\n");
-
-  fwrite(content, 1, len, fp);
-  fflush(fp);
-  fclose(fp);
-  free(content);
-  
-  dInfo("save dnodeId successed");
-}
-
-void dnodeUpdateDnodeCfg(SDMDnodeCfg *pCfg) {
-  if (tsDnodeCfg.dnodeId == 0) {
-    dInfo("dnodeId is set to %d, clusterId is set to %s", pCfg->dnodeId, pCfg->clusterId);  
-    tsDnodeCfg.dnodeId = pCfg->dnodeId;
-    tstrncpy(tsDnodeCfg.clusterId, pCfg->clusterId, TSDB_CLUSTER_ID_LEN);
-    dnodeSaveDnodeCfg();
-  }
-}
-
-int32_t dnodeGetDnodeId() {
-  return tsDnodeCfg.dnodeId;
-}
-
 void dnodeSendRedirectMsg(SRpcMsg *rpcMsg, bool forShell) {
   SRpcConnInfo connInfo = {0};
   rpcGetConnInfo(rpcMsg->handle, &connInfo);
 
   SRpcEpSet epSet = {0};
   if (forShell) {
-    dnodeGetMnodeEpSetForShell(&epSet);
+    dnodeGetEpSetForShell(&epSet);
   } else {
-    dnodeGetMnodeEpSetForPeer(&epSet);
+    dnodeGetEpSetForPeer(&epSet);
   }
   
   dDebug("msg:%s will be redirected, dnodeIp:%s user:%s, numOfEps:%d inUse:%d", taosMsg[rpcMsg->msgType],
diff --git a/src/dnode/src/dnodeModule.c b/src/dnode/src/dnodeModule.c
index 46376159c6..bd9500ba51 100644
--- a/src/dnode/src/dnodeModule.c
+++ b/src/dnode/src/dnodeModule.c
@@ -114,6 +114,7 @@ int32_t dnodeInitModules() {
     }
   }
 
+  dInfo("dnode modules is initialized");
   return 0;
 }
 
@@ -146,8 +147,8 @@ void dnodeProcessModuleStatus(uint32_t moduleStatus) {
   }
 }
 
-bool dnodeStartMnode(void *pMnodes) {
-  SDMMnodeInfos *mnodes = pMnodes;
+bool dnodeStartMnode(SMnodeInfos *minfos) {
+  SMnodeInfos *mnodes = minfos;
 
   if (tsModuleStatus & (1 << TSDB_MOD_MNODE)) {
     dDebug("mnode module is already started, module status:%d", tsModuleStatus);
diff --git a/src/dnode/src/dnodePeer.c b/src/dnode/src/dnodePeer.c
index 3bc2f7b48b..a7c76a3473 100644
--- a/src/dnode/src/dnodePeer.c
+++ b/src/dnode/src/dnodePeer.c
@@ -28,8 +28,8 @@
 #include "dnodeMgmt.h"
 #include "dnodeVWrite.h"
 #include "dnodeMPeer.h"
+#include "dnodeMInfos.h"
 
-extern void dnodeUpdateMnodeEpSetForPeer(SRpcEpSet *pEpSet);
 static void (*dnodeProcessReqMsgFp[TSDB_MSG_TYPE_MAX])(SRpcMsg *);
 static void dnodeProcessReqMsgFromDnode(SRpcMsg *pMsg, SRpcEpSet *);
 static void (*dnodeProcessRspMsgFp[TSDB_MSG_TYPE_MAX])(SRpcMsg *rpcMsg);
@@ -72,7 +72,7 @@ int32_t dnodeInitServer() {
     return -1;
   }
 
-  dInfo("inter-dnodes RPC server is opened");
+  dInfo("dnode inter-dnodes RPC server is initialized");
   return 0;
 }
 
@@ -137,7 +137,7 @@ int32_t dnodeInitClient() {
     return -1;
   }
 
-  dInfo("inter-dnodes rpc client is opened");
+  dInfo("dnode inter-dnodes rpc client is initialized");
   return 0;
 }
 
@@ -145,13 +145,13 @@ void dnodeCleanupClient() {
   if (tsDnodeClientRpc) {
     rpcClose(tsDnodeClientRpc);
     tsDnodeClientRpc = NULL;
-    dInfo("inter-dnodes rpc client is closed");
+    dInfo("dnode inter-dnodes rpc client is closed");
   }
 }
 
 static void dnodeProcessRspFromDnode(SRpcMsg *pMsg, SRpcEpSet *pEpSet) {
   if (pMsg->msgType == TSDB_MSG_TYPE_DM_STATUS_RSP && pEpSet) {
-    dnodeUpdateMnodeEpSetForPeer(pEpSet);
+    dnodeUpdateEpSetForPeer(pEpSet);
   }
 
   if (dnodeProcessRspMsgFp[pMsg->msgType]) {    
@@ -173,7 +173,7 @@ void dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg) {
 
 void dnodeSendMsgToMnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp) {
   SRpcEpSet epSet = {0};
-  dnodeGetMnodeEpSetForPeer(&epSet);
+  dnodeGetEpSetForPeer(&epSet);
   rpcSendRecv(tsDnodeClientRpc, &epSet, rpcMsg, rpcRsp);
 }
 
diff --git a/src/dnode/src/dnodeShell.c b/src/dnode/src/dnodeShell.c
index 4c6c2100e0..35ea6ae8b3 100644
--- a/src/dnode/src/dnodeShell.c
+++ b/src/dnode/src/dnodeShell.c
@@ -97,7 +97,7 @@ int32_t dnodeInitShell() {
     return -1;
   }
 
-  dInfo("shell rpc server is opened");
+  dInfo("dnode shell rpc server is initialized");
   return 0;
 }
 
@@ -146,12 +146,12 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
   int code = mnodeRetriveAuth(user, spi, encrypt, secret, ckey);
   if (code != TSDB_CODE_APP_NOT_READY) return code;
 
-  SDMAuthMsg *pMsg = rpcMallocCont(sizeof(SDMAuthMsg));
+  SAuthMsg *pMsg = rpcMallocCont(sizeof(SAuthMsg));
   tstrncpy(pMsg->user, user, sizeof(pMsg->user));
 
   SRpcMsg rpcMsg = {0};
   rpcMsg.pCont = pMsg;
-  rpcMsg.contLen = sizeof(SDMAuthMsg);
+  rpcMsg.contLen = sizeof(SAuthMsg);
   rpcMsg.msgType = TSDB_MSG_TYPE_DM_AUTH;
   
   dDebug("user:%s, send auth msg to mnodes", user);
@@ -161,7 +161,7 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
   if (rpcRsp.code != 0) {
     dError("user:%s, auth msg received from mnodes, error:%s", user, tstrerror(rpcRsp.code));
   } else {
-    SDMAuthRsp *pRsp = rpcRsp.pCont;
+    SAuthRsp *pRsp = rpcRsp.pCont;
     dDebug("user:%s, auth msg received from mnodes", user);
     memcpy(secret, pRsp->secret, TSDB_KEY_LEN);
     memcpy(ckey, pRsp->ckey, TSDB_KEY_LEN);
@@ -176,8 +176,8 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
 void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t tid) {
   dDebug("vgId:%d, tid:%d send config table msg to mnode", vgId, tid);
 
-  int32_t contLen = sizeof(SDMConfigTableMsg);
-  SDMConfigTableMsg *pMsg = rpcMallocCont(contLen);
+  int32_t contLen = sizeof(SConfigTableMsg);
+  SConfigTableMsg *pMsg = rpcMallocCont(contLen);
 
   pMsg->dnodeId = htonl(dnodeGetDnodeId());
   pMsg->vgId = htonl(vgId);
diff --git a/src/dnode/src/dnodeTelemetry.c b/src/dnode/src/dnodeTelemetry.c
index 4fdc0b8a73..ab58e0470f 100644
--- a/src/dnode/src/dnodeTelemetry.c
+++ b/src/dnode/src/dnodeTelemetry.c
@@ -299,6 +299,7 @@ int32_t dnodeInitTelemetry() {
     dTrace("failed to create telemetry thread, reason:%s", strerror(errno));
   }
 
+  dInfo("dnode telemetry is initialized");
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeVRead.c b/src/dnode/src/dnodeVRead.c
index e61158ef30..cd913cc100 100644
--- a/src/dnode/src/dnodeVRead.c
+++ b/src/dnode/src/dnodeVRead.c
@@ -61,7 +61,7 @@ int32_t dnodeInitVnodeRead() {
     pWorker->workerId = i;
   }
 
-  dInfo("dnode read is opened, min worker:%d max worker:%d", readPool.min, readPool.max);
+  dInfo("dnode read is initialized, min worker:%d max worker:%d", readPool.min, readPool.max);
   return 0;
 }
 
diff --git a/src/dnode/src/dnodeVWrite.c b/src/dnode/src/dnodeVWrite.c
index f2740bf6b8..d36c140f43 100644
--- a/src/dnode/src/dnodeVWrite.c
+++ b/src/dnode/src/dnodeVWrite.c
@@ -69,7 +69,7 @@ int32_t dnodeInitVnodeWrite() {
     wWorkerPool.writeWorker[i].workerId = i;
   }
 
-  dInfo("dnode write is opened, max worker %d", wWorkerPool.max);
+  dInfo("dnode write is initialized, max worker %d", wWorkerPool.max);
   return 0;
 }
 
diff --git a/src/inc/dnode.h b/src/inc/dnode.h
index e84545be17..f7ebed31cf 100644
--- a/src/inc/dnode.h
+++ b/src/inc/dnode.h
@@ -21,6 +21,7 @@ extern "C" {
 #endif
 
 #include "trpc.h"
+#include "taosmsg.h"
 
 typedef struct {
   int32_t queryReqNum;
@@ -38,12 +39,13 @@ SDnodeRunStatus dnodeGetRunStatus();
 SDnodeStatisInfo dnodeGetStatisInfo();
 
 bool    dnodeIsFirstDeploy();
-char *  dnodeGetMnodeMasterEp();
-void    dnodeGetMnodeEpSetForPeer(void *epSet);
-void    dnodeGetMnodeEpSetForShell(void *epSet);
-void *  dnodeGetMnodeInfos();
+bool    dnodeIsMasterEp(char *ep);
+void    dnodeGetEpSetForPeer(SRpcEpSet *epSet);
+void    dnodeGetEpSetForShell(SRpcEpSet *epSet);
 int32_t dnodeGetDnodeId();
-bool    dnodeStartMnode(void *pModes);
+void    dnodeUpdateEp(int32_t dnodeId, char *ep, char *fqdn, uint16_t *port);
+bool    dnodeCheckEpChanged(int32_t dnodeId, char *epstr);
+bool    dnodeStartMnode(SMnodeInfos *minfos);
 
 void  dnodeAddClientRspHandle(uint8_t msgType, void (*fp)(SRpcMsg *rpcMsg));
 void  dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg);
diff --git a/src/inc/taosmsg.h b/src/inc/taosmsg.h
index 1c36934688..743616e08e 100644
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@@ -295,7 +295,7 @@ typedef struct {
   SSchema schema[];
   // tagVal is padded after schema
   // char    tagVal[];
-} SCMAlterTableMsg;
+} SAlterTableMsg;
 
 typedef struct {
   SMsgHead  head;
@@ -312,12 +312,12 @@ typedef struct {
 } SUpdateTableTagValMsg;
 
 typedef struct {
-  char clientVersion[TSDB_VERSION_LEN];
-  char msgVersion[TSDB_VERSION_LEN];
-  char db[TSDB_TABLE_FNAME_LEN];
-  char appName[TSDB_APPNAME_LEN];
+  char    clientVersion[TSDB_VERSION_LEN];
+  char    msgVersion[TSDB_VERSION_LEN];
+  char    db[TSDB_TABLE_FNAME_LEN];
+  char    appName[TSDB_APPNAME_LEN];
   int32_t pid;
-} SCMConnectMsg;
+} SConnectMsg;
 
 typedef struct {
   char      acctId[TSDB_ACCT_LEN];
@@ -328,7 +328,7 @@ typedef struct {
   int8_t    reserved2;
   int32_t   connId;
   SRpcEpSet epSet;
-} SCMConnectRsp;
+} SConnectRsp;
 
 typedef struct {
   int32_t maxUsers;
@@ -348,18 +348,18 @@ typedef struct {
   char     user[TSDB_USER_LEN];
   char     pass[TSDB_KEY_LEN];
   SAcctCfg cfg;
-} SCMCreateAcctMsg, SCMAlterAcctMsg;
+} SCreateAcctMsg, SAlterAcctMsg;
 
 typedef struct {
   char user[TSDB_USER_LEN];
-} SCMDropUserMsg, SCMDropAcctMsg;
+} SDropUserMsg, SDropAcctMsg;
 
 typedef struct {
   char   user[TSDB_USER_LEN];
   char   pass[TSDB_KEY_LEN];
   int8_t privilege;
   int8_t flag;
-} SCMCreateUserMsg, SCMAlterUserMsg;
+} SCreateUserMsg, SAlterUserMsg;
 
 typedef struct {
   int32_t  contLen;
@@ -374,11 +374,11 @@ typedef struct {
   int32_t  vgId;
   uint64_t uid;
   char    tableId[TSDB_TABLE_FNAME_LEN];
-} SMDDropSTableMsg;
+} SDropSTableMsg;
 
 typedef struct {
   int32_t vgId;
-} SMDDropVnodeMsg;
+} SDropVnodeMsg;
 
 typedef struct SColIndex {
   int16_t  colId;      // column id
@@ -546,12 +546,12 @@ typedef struct {
   int8_t   ignoreExist;
   int8_t   update;
   int8_t   reserve[9];
-} SCMCreateDbMsg, SCMAlterDbMsg;
+} SCreateDbMsg, SAlterDbMsg;
 
 typedef struct {
   char    db[TSDB_TABLE_FNAME_LEN];
   uint8_t ignoreNotExists;
-} SCMDropDbMsg, SCMUseDbMsg;
+} SDropDbMsg, SUseDbMsg;
 
 // IMPORTANT: sizeof(SVnodeStatisticInfo) should not exceed
 // TSDB_FILE_HEADER_LEN/4 - TSDB_FILE_HEADER_VERSION_SIZE
@@ -566,7 +566,7 @@ typedef struct {
 typedef struct {
   int32_t  vgId;
   int8_t   accessState;
-} SDMVgroupAccess;
+} SVgroupAccess;
 
 typedef struct {
   int32_t  dnodeId;
@@ -574,18 +574,29 @@ typedef struct {
   uint32_t numOfVnodes;
   char     clusterId[TSDB_CLUSTER_ID_LEN];
   char     reserved[16];
-} SDMDnodeCfg;
+} SDnodeCfg;
 
 typedef struct {
-  int32_t   nodeId;
-  char      nodeEp[TSDB_EP_LEN];
-} SDMMnodeInfo;
+  int32_t  dnodeId;
+  uint16_t dnodePort;
+  char     dnodeFqdn[TSDB_FQDN_LEN];
+} SDnodeEp;
 
 typedef struct {
-  int8_t       inUse;
-  int8_t       nodeNum;
-  SDMMnodeInfo nodeInfos[TSDB_MAX_REPLICA];
-} SDMMnodeInfos;
+  int32_t  dnodeNum;
+  SDnodeEp dnodeEps[];
+} SDnodeEps;
+
+typedef struct {
+  int32_t mnodeId;
+  char    mnodeEp[TSDB_EP_LEN];
+} SMnodeInfo;
+
+typedef struct {
+  int8_t     inUse;
+  int8_t     mnodeNum;
+  SMnodeInfo mnodeInfos[TSDB_MAX_REPLICA];
+} SMnodeInfos;
 
 typedef struct {
   int32_t  numOfMnodes;               // tsNumOfMnodes
@@ -617,13 +628,13 @@ typedef struct {
   uint8_t     reserve2[15];
   SClusterCfg clusterCfg;
   SVnodeLoad  load[];
-} SDMStatusMsg;
+} SStatusMsg;
 
 typedef struct {
-  SDMMnodeInfos    mnodes;
-  SDMDnodeCfg      dnodeCfg;
-  SDMVgroupAccess  vgAccess[];
-} SDMStatusRsp;
+  SMnodeInfos   mnodes;
+  SDnodeCfg     dnodeCfg;
+  SVgroupAccess vgAccess[];
+} SStatusRsp;
 
 typedef struct {
   uint32_t vgId;
@@ -647,54 +658,54 @@ typedef struct {
   int8_t   quorum;
   int8_t   update;
   int8_t   reserved[15];
-} SMDVnodeCfg;
+} SVnodeCfg;
 
 typedef struct {
   int32_t  nodeId;
   char     nodeEp[TSDB_EP_LEN];
-} SMDVnodeDesc;
+} SVnodeDesc;
 
 typedef struct {
-  char db[TSDB_ACCT_LEN + TSDB_DB_NAME_LEN];
-  SMDVnodeCfg  cfg;
-  SMDVnodeDesc nodes[TSDB_MAX_REPLICA];
-} SMDCreateVnodeMsg, SMDAlterVnodeMsg;
+  char       db[TSDB_ACCT_LEN + TSDB_DB_NAME_LEN];
+  SVnodeCfg  cfg;
+  SVnodeDesc nodes[TSDB_MAX_REPLICA];
+} SCreateVnodeMsg, SAlterVnodeMsg;
 
 typedef struct {
   char    tableId[TSDB_TABLE_FNAME_LEN];
   int16_t createFlag;
   char    tags[];
-} SCMTableInfoMsg;
+} STableInfoMsg;
 
 typedef struct {
   int32_t numOfTables;
   char    tableIds[];
-} SCMMultiTableInfoMsg;
+} SMultiTableInfoMsg;
 
-typedef struct SCMSTableVgroupMsg {
+typedef struct SSTableVgroupMsg {
   int32_t numOfTables;
-} SCMSTableVgroupMsg, SCMSTableVgroupRspMsg;
+} SSTableVgroupMsg, SSTableVgroupRspMsg;
 
 typedef struct {
   int32_t       vgId;
   int8_t        numOfEps;
   SEpAddr1      epAddr[TSDB_MAX_REPLICA];
-} SCMVgroupInfo;
+} SVgroupInfo;
 
 typedef struct {
   int32_t    vgId;
   int8_t     numOfEps;
   SEpAddrMsg epAddr[TSDB_MAX_REPLICA];
-} SCMVgroupMsg;
+} SVgroupMsg;
 
 typedef struct {
   int32_t numOfVgroups;
-  SCMVgroupInfo vgroups[];
+  SVgroupInfo vgroups[];
 } SVgroupsInfo;
 
 typedef struct {
   int32_t numOfVgroups;
-  SCMVgroupMsg vgroups[];
+  SVgroupMsg vgroups[];
 } SVgroupsMsg;
 
 typedef struct STableMetaMsg {
@@ -709,7 +720,7 @@ typedef struct STableMetaMsg {
   int16_t       tversion;
   int32_t       tid;
   uint64_t      uid;
-  SCMVgroupMsg  vgroup;
+  SVgroupMsg    vgroup;
   SSchema       schema[];
 } STableMetaMsg;
 
@@ -735,38 +746,38 @@ typedef struct {
   char     db[TSDB_ACCT_LEN + TSDB_DB_NAME_LEN];
   uint16_t payloadLen;
   char     payload[];
-} SCMShowMsg;
+} SShowMsg;
 
-typedef struct SCMShowRsp {
+typedef struct SShowRsp {
   uint64_t      qhandle;
   STableMetaMsg tableMeta;
-} SCMShowRsp;
+} SShowRsp;
 
 typedef struct {
-  char     ep[TSDB_EP_LEN];  // end point, hostname:port
-} SCMCreateDnodeMsg, SCMDropDnodeMsg;
+  char ep[TSDB_EP_LEN];  // end point, hostname:port
+} SCreateDnodeMsg, SDropDnodeMsg;
 
 typedef struct {
   int32_t dnodeId;
   char    dnodeEp[TSDB_EP_LEN];  // end point, hostname:port
-  SDMMnodeInfos mnodes;
-} SMDCreateMnodeMsg;
+  SMnodeInfos mnodes;
+} SCreateMnodeMsg;
 
 typedef struct {
   int32_t dnodeId;
   int32_t vgId;
   int32_t tid;
-} SDMConfigTableMsg;
+} SConfigTableMsg;
 
 typedef struct {
   uint32_t dnodeId;
   int32_t  vgId;
-} SDMConfigVnodeMsg;
+} SConfigVnodeMsg;
 
 typedef struct {
   char ep[TSDB_EP_LEN];  // end point, hostname:port
   char config[64];
-} SMDCfgDnodeMsg, SCMCfgDnodeMsg;
+} SCfgDnodeMsg;
 
 typedef struct {
   char     sql[TSDB_SHOW_SQL_LEN];
@@ -795,7 +806,7 @@ typedef struct {
   int32_t  numOfStreams;
   char     appName[TSDB_APPNAME_LEN];
   char     pData[];
-} SCMHeartBeatMsg;
+} SHeartBeatMsg;
 
 typedef struct {
   uint32_t  queryId;
@@ -805,11 +816,11 @@ typedef struct {
   uint32_t  connId;
   int8_t    killConnection;
   SRpcEpSet epSet;
-} SCMHeartBeatRsp;
+} SHeartBeatRsp;
 
 typedef struct {
   char queryId[TSDB_KILL_MSG_LEN + 1];
-} SCMKillQueryMsg, SCMKillStreamMsg, SCMKillConnMsg;
+} SKillQueryMsg, SKillStreamMsg, SKillConnMsg;
 
 typedef struct {
   int32_t  vnode;
@@ -818,7 +829,7 @@ typedef struct {
   uint64_t stime;  // stream starting time
   int32_t  status;
   char     tableId[TSDB_TABLE_FNAME_LEN];
-} SMDAlterStreamMsg;
+} SAlterStreamMsg;
 
 typedef struct {
   char user[TSDB_USER_LEN];
@@ -826,7 +837,7 @@ typedef struct {
   char encrypt;
   char secret[TSDB_KEY_LEN];
   char ckey[TSDB_KEY_LEN];
-} SDMAuthMsg, SDMAuthRsp;
+} SAuthMsg, SAuthRsp;
 
 #pragma pack(pop)
 
diff --git a/src/inc/tsync.h b/src/inc/tsync.h
index ca0f70d104..671adefab8 100644
--- a/src/inc/tsync.h
+++ b/src/inc/tsync.h
@@ -68,7 +68,7 @@ typedef uint32_t (*FGetFileInfo)(void *ahandle, char *name, uint32_t *index, uin
 
 // get the wal file from index or after
 // return value, -1: error, 1:more wal files, 0:last WAL. if name[0]==0, no WAL file
-typedef int      (*FGetWalInfo)(void *ahandle, char *name, uint32_t *index); 
+typedef int32_t  (*FGetWalInfo)(void *ahandle, char *fileName, int64_t *fileId); 
  
 // when a forward pkt is received, call this to handle data 
 typedef int      (*FWriteToCache)(void *ahandle, void *pHead, int type);
diff --git a/src/inc/twal.h b/src/inc/twal.h
index 1ce7b132b0..94bdcacfce 100644
--- a/src/inc/twal.h
+++ b/src/inc/twal.h
@@ -19,9 +19,11 @@
 extern "C" {
 #endif
 
-#define TAOS_WAL_NOLOG   0
-#define TAOS_WAL_WRITE   1
-#define TAOS_WAL_FSYNC   2
+typedef enum {
+  TAOS_WAL_NOLOG = 0,
+  TAOS_WAL_WRITE = 1,
+  TAOS_WAL_FSYNC = 2
+} EWalType;
 
 typedef struct {
   int8_t   msgType;
@@ -34,8 +36,9 @@ typedef struct {
 } SWalHead;
 
 typedef struct {
-  int8_t  walLevel;     // wal level
+  int32_t vgId;
   int32_t fsyncPeriod;  // millisecond
+  int8_t  walLevel;     // wal level
   int8_t  wals;         // number of WAL files;
   int8_t  keep;         // keep the wal file when closed
 } SWalCfg;
@@ -43,14 +46,17 @@ typedef struct {
 typedef void* twalh;  // WAL HANDLE
 typedef int (*FWalWrite)(void *ahandle, void *pHead, int type);
 
-twalh   walOpen(const char *path, const SWalCfg *pCfg);
-int     walAlter(twalh pWal, const SWalCfg *pCfg);
+int32_t walInit();
+void    walCleanUp();
+
+twalh   walOpen(char *path, SWalCfg *pCfg);
+int32_t walAlter(twalh pWal, SWalCfg *pCfg);
 void    walClose(twalh);
-int     walRenew(twalh);
-int     walWrite(twalh, SWalHead *);
+int32_t walRenew(twalh);
+int32_t walWrite(twalh, SWalHead *);
 void    walFsync(twalh);
-int     walRestore(twalh, void *pVnode, FWalWrite writeFp);
-int     walGetWalFile(twalh, char *name, uint32_t *index);
+int32_t walRestore(twalh, void *pVnode, FWalWrite writeFp);
+int32_t walGetWalFile(twalh, char *fileName, int64_t *fileId);
 int64_t walGetVersion(twalh);
 
 #ifdef __cplusplus
diff --git a/src/inc/vnode.h b/src/inc/vnode.h
index fdce4d6279..8c387065cc 100644
--- a/src/inc/vnode.h
+++ b/src/inc/vnode.h
@@ -43,10 +43,10 @@ typedef struct {
 
 extern char *vnodeStatus[];
 
-int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg);
+int32_t vnodeCreate(SCreateVnodeMsg *pVnodeCfg);
 int32_t vnodeDrop(int32_t vgId);
 int32_t vnodeOpen(int32_t vgId, char *rootDir);
-int32_t vnodeAlter(void *pVnode, SMDCreateVnodeMsg *pVnodeCfg);
+int32_t vnodeAlter(void *pVnode, SCreateVnodeMsg *pVnodeCfg);
 int32_t vnodeClose(int32_t vgId);
 
 void*   vnodeAcquire(int32_t vgId);        // add refcount
@@ -60,7 +60,7 @@ int32_t vnodeCheckWrite(void *pVnode);
 int32_t vnodeGetVnodeList(int32_t vnodeList[], int32_t *numOfVnodes);
 void    vnodeBuildStatusMsg(void *param);
 void    vnodeConfirmForward(void *param, uint64_t version, int32_t code);
-void    vnodeSetAccess(SDMVgroupAccess *pAccess, int32_t numOfVnodes);
+void    vnodeSetAccess(SVgroupAccess *pAccess, int32_t numOfVnodes);
 
 int32_t vnodeInitResources();
 void    vnodeCleanupResources();
diff --git a/src/mnode/inc/mnodeProfile.h b/src/mnode/inc/mnodeProfile.h
index 1e5b1c0f9c..ee57c5da1f 100644
--- a/src/mnode/inc/mnodeProfile.h
+++ b/src/mnode/inc/mnodeProfile.h
@@ -45,7 +45,7 @@ void    mnodeCleanupProfile();
 SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port, int32_t pid, const char* app);
 SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t port);
 void      mnodeReleaseConn(SConnObj *pConn);
-int32_t   mnodeSaveQueryStreamList(SConnObj *pConn, SCMHeartBeatMsg *pHBMsg);
+int32_t   mnodeSaveQueryStreamList(SConnObj *pConn, SHeartBeatMsg *pHBMsg);
 
 #ifdef __cplusplus
 }
diff --git a/src/mnode/src/mnodeDb.c b/src/mnode/src/mnodeDb.c
index 5ceb5888e9..812b1c609f 100644
--- a/src/mnode/src/mnodeDb.c
+++ b/src/mnode/src/mnodeDb.c
@@ -41,7 +41,7 @@
 static void *  tsDbSdb = NULL;
 static int32_t tsDbUpdateSize;
 
-static int32_t mnodeCreateDb(SAcctObj *pAcct, SCMCreateDbMsg *pCreate, SMnodeMsg *pMsg);
+static int32_t mnodeCreateDb(SAcctObj *pAcct, SCreateDbMsg *pCreate, SMnodeMsg *pMsg);
 static int32_t mnodeDropDb(SMnodeMsg *newMsg);
 static int32_t mnodeSetDbDropping(SDbObj *pDb);
 static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
@@ -358,7 +358,7 @@ static int32_t mnodeCreateDbCb(SMnodeMsg *pMsg, int32_t code) {
   return code;
 }
 
-static int32_t mnodeCreateDb(SAcctObj *pAcct, SCMCreateDbMsg *pCreate, SMnodeMsg *pMsg) {
+static int32_t mnodeCreateDb(SAcctObj *pAcct, SCreateDbMsg *pCreate, SMnodeMsg *pMsg) {
   int32_t code = acctCheck(pAcct, ACCT_GRANT_DB);
   if (code != 0) return code;
 
@@ -822,7 +822,7 @@ static int32_t mnodeSetDbDropping(SDbObj *pDb) {
 }
 
 static int32_t mnodeProcessCreateDbMsg(SMnodeMsg *pMsg) {
-  SCMCreateDbMsg *pCreate  = pMsg->rpcMsg.pCont;  
+  SCreateDbMsg *pCreate    = pMsg->rpcMsg.pCont;  
   pCreate->maxTables       = htonl(pCreate->maxTables);
   pCreate->cacheBlockSize  = htonl(pCreate->cacheBlockSize);
   pCreate->totalBlocks     = htonl(pCreate->totalBlocks);
@@ -847,7 +847,7 @@ static int32_t mnodeProcessCreateDbMsg(SMnodeMsg *pMsg) {
   return code;
 }
 
-static SDbCfg mnodeGetAlterDbOption(SDbObj *pDb, SCMAlterDbMsg *pAlter) {
+static SDbCfg mnodeGetAlterDbOption(SDbObj *pDb, SAlterDbMsg *pAlter) {
   SDbCfg  newCfg = pDb->cfg;
   int32_t maxTables      = htonl(pAlter->maxTables);
   int32_t cacheBlockSize = htonl(pAlter->cacheBlockSize);
@@ -1000,7 +1000,7 @@ static int32_t mnodeAlterDbCb(SMnodeMsg *pMsg, int32_t code) {
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t mnodeAlterDb(SDbObj *pDb, SCMAlterDbMsg *pAlter, void *pMsg) {
+static int32_t mnodeAlterDb(SDbObj *pDb, SAlterDbMsg *pAlter, void *pMsg) {
   SDbCfg newCfg = mnodeGetAlterDbOption(pDb, pAlter);
   if (terrno != TSDB_CODE_SUCCESS) {
     return terrno;
@@ -1032,7 +1032,7 @@ static int32_t mnodeAlterDb(SDbObj *pDb, SCMAlterDbMsg *pAlter, void *pMsg) {
 }
 
 static int32_t mnodeProcessAlterDbMsg(SMnodeMsg *pMsg) {
-  SCMAlterDbMsg *pAlter = pMsg->rpcMsg.pCont;
+  SAlterDbMsg *pAlter = pMsg->rpcMsg.pCont;
   mDebug("db:%s, alter db msg is received from thandle:%p", pAlter->db, pMsg->rpcMsg.handle);
 
   if (pMsg->pDb == NULL) pMsg->pDb = mnodeGetDb(pAlter->db);
@@ -1083,7 +1083,7 @@ static int32_t mnodeDropDb(SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessDropDbMsg(SMnodeMsg *pMsg) {
-  SCMDropDbMsg *pDrop = pMsg->rpcMsg.pCont;
+  SDropDbMsg *pDrop = pMsg->rpcMsg.pCont;
   mDebug("db:%s, drop db msg is received from thandle:%p", pDrop->db, pMsg->rpcMsg.handle);
 
   if (pMsg->pDb == NULL) pMsg->pDb = mnodeGetDb(pDrop->db);
diff --git a/src/mnode/src/mnodeDnode.c b/src/mnode/src/mnodeDnode.c
index 1cd861e223..bf8647c193 100644
--- a/src/mnode/src/mnodeDnode.c
+++ b/src/mnode/src/mnodeDnode.c
@@ -39,11 +39,15 @@
 #include "mnodeCluster.h"
 
 int32_t tsAccessSquence = 0;
-static void   *tsDnodeSdb = NULL;
+static void *  tsDnodeSdb = NULL;
 static int32_t tsDnodeUpdateSize = 0;
 extern void *  tsMnodeSdb;
 extern void *  tsVgroupSdb;
 
+static SDnodeEps*tsDnodeEps;
+static int32_t   tsDnodeEpsSize;
+static pthread_mutex_t tsDnodeEpsMutex;
+
 static int32_t mnodeCreateDnode(char *ep, SMnodeMsg *pMsg);
 static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg);
 static int32_t mnodeProcessDropDnodeMsg(SMnodeMsg *pMsg);
@@ -59,6 +63,7 @@ static int32_t mnodeRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, vo
 static int32_t mnodeGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
 static int32_t mnodeRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);
 static char*   mnodeGetDnodeAlternativeRoleStr(int32_t alternativeRole);
+static void    mnodeUpdateDnodeEps();
 
 static char* offlineReason[] = {
   "",
@@ -95,6 +100,9 @@ static int32_t mnodeDnodeActionInsert(SSdbOper *pOper) {
     pDnode->offlineReason = TAOS_DN_OFF_STATUS_NOT_RECEIVED;
   }
 
+  dnodeUpdateEp(pDnode->dnodeId, pDnode->dnodeEp, pDnode->dnodeFqdn, &pDnode->dnodePort);
+  mnodeUpdateDnodeEps();
+
   mInfo("dnode:%d, fqdn:%s ep:%s port:%d, do insert action", pDnode->dnodeId, pDnode->dnodeFqdn, pDnode->dnodeEp, pDnode->dnodePort);
   return TSDB_CODE_SUCCESS;
 }
@@ -107,6 +115,7 @@ static int32_t mnodeDnodeActionDelete(SSdbOper *pOper) {
 #endif  
   mnodeDropMnodeLocal(pDnode->dnodeId);
   balanceAsyncNotify();
+  mnodeUpdateDnodeEps();
 
   mDebug("dnode:%d, all vgroups is dropped from sdb", pDnode->dnodeId);
   return TSDB_CODE_SUCCESS;
@@ -121,6 +130,7 @@ static int32_t mnodeDnodeActionUpdate(SSdbOper *pOper) {
   }
   mnodeDecDnodeRef(pDnode);
 
+  mnodeUpdateDnodeEps();
   return TSDB_CODE_SUCCESS;
 }
 
@@ -152,12 +162,14 @@ static int32_t mnodeDnodeActionRestored() {
     }
   }
 
+  mnodeUpdateDnodeEps();
   return TSDB_CODE_SUCCESS;
 }
 
 int32_t mnodeInitDnodes() {
   SDnodeObj tObj;
   tsDnodeUpdateSize = (int8_t *)tObj.updateEnd - (int8_t *)&tObj;
+  pthread_mutex_init(&tsDnodeEpsMutex, NULL);
 
   SSdbTableDesc tableDesc = {
     .tableId      = SDB_TABLE_DNODE,
@@ -201,6 +213,9 @@ int32_t mnodeInitDnodes() {
 
 void mnodeCleanupDnodes() {
   sdbCloseTable(tsDnodeSdb);
+  pthread_mutex_destroy(&tsDnodeEpsMutex);
+  free(tsDnodeEps);
+  tsDnodeEps = NULL;
   tsDnodeSdb = NULL;
 }
 
@@ -299,7 +314,7 @@ static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg) {
     return TSDB_CODE_MND_NO_RIGHTS;
   }
   
-  SCMCfgDnodeMsg *pCmCfgDnode = pMsg->rpcMsg.pCont;
+  SCfgDnodeMsg *pCmCfgDnode = pMsg->rpcMsg.pCont;
   if (pCmCfgDnode->ep[0] == 0) {
     tstrncpy(pCmCfgDnode->ep, tsLocalEp, TSDB_EP_LEN);
   }
@@ -334,7 +349,7 @@ static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg) {
     mnodeDecDnodeRef(pDnode);
     return code;
   } else {
-    SMDCfgDnodeMsg *pMdCfgDnode = rpcMallocCont(sizeof(SMDCfgDnodeMsg));
+    SCfgDnodeMsg *pMdCfgDnode = rpcMallocCont(sizeof(SCfgDnodeMsg));
     strcpy(pMdCfgDnode->ep, pCmCfgDnode->ep);
     strcpy(pMdCfgDnode->config, pCmCfgDnode->config);
 
@@ -343,7 +358,7 @@ static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg) {
       .code = 0,
       .msgType = TSDB_MSG_TYPE_MD_CONFIG_DNODE,
       .pCont = pMdCfgDnode,
-      .contLen = sizeof(SMDCfgDnodeMsg)
+      .contLen = sizeof(SCfgDnodeMsg)
     };
 
     mInfo("dnode:%s, is configured by %s", pCmCfgDnode->ep, pMsg->pUser->user);
@@ -418,9 +433,54 @@ static int32_t mnodeCheckClusterCfgPara(const SClusterCfg *clusterCfg) {
   return 0;
 }
 
+static int32_t mnodeGetDnodeEpsSize() {
+  pthread_mutex_lock(&tsDnodeEpsMutex);
+  int32_t size = tsDnodeEpsSize;
+  pthread_mutex_unlock(&tsDnodeEpsMutex);
+  return size;
+}
+
+static void mnodeGetDnodeEpsData(SDnodeEps *pEps, int32_t epsSize) {
+  pthread_mutex_lock(&tsDnodeEpsMutex);
+  if (epsSize == tsDnodeEpsSize) {
+    memcpy(pEps, tsDnodeEps, tsDnodeEpsSize);
+  }
+  pthread_mutex_unlock(&tsDnodeEpsMutex);
+}
+
+static void mnodeUpdateDnodeEps() {
+  pthread_mutex_lock(&tsDnodeEpsMutex);
+
+  int32_t totalDnodes = mnodeGetDnodesNum();
+  tsDnodeEpsSize = sizeof(SDnodeEps) + totalDnodes * sizeof(SDnodeEp);
+  free(tsDnodeEps);
+  tsDnodeEps = calloc(1, tsDnodeEpsSize);
+  tsDnodeEps->dnodeNum = htonl(totalDnodes);
+
+  SDnodeObj *pDnode = NULL;
+  void *     pIter = NULL;
+  int32_t    dnodesNum = 0;
+
+  while (1) {
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+    if (dnodesNum >= totalDnodes) break;
+
+    SDnodeEp *pEp = &tsDnodeEps->dnodeEps[dnodesNum];
+    dnodesNum++;
+    pEp->dnodeId = htonl(pDnode->dnodeId);
+    pEp->dnodePort = htons(pDnode->dnodePort);
+    tstrncpy(pEp->dnodeFqdn, pDnode->dnodeFqdn, TSDB_FQDN_LEN);
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  sdbFreeIter(pIter);
+  pthread_mutex_unlock(&tsDnodeEpsMutex);
+}
+
 static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
   SDnodeObj *pDnode     = NULL;
-  SDMStatusMsg *pStatus = pMsg->rpcMsg.pCont;
+  SStatusMsg *pStatus   = pMsg->rpcMsg.pCont;
   pStatus->dnodeId      = htonl(pStatus->dnodeId);
   pStatus->moduleStatus = htonl(pStatus->moduleStatus);
   pStatus->lastReboot   = htonl(pStatus->lastReboot);
@@ -477,8 +537,11 @@ static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
   }
 
   int32_t openVnodes = htons(pStatus->openVnodes);
-  int32_t contLen = sizeof(SDMStatusRsp) + openVnodes * sizeof(SDMVgroupAccess);
-  SDMStatusRsp *pRsp = rpcMallocCont(contLen);
+  int32_t epsSize = mnodeGetDnodeEpsSize();
+  int32_t vgAccessSize = openVnodes * sizeof(SVgroupAccess);
+  int32_t contLen = sizeof(SStatusRsp) + vgAccessSize + epsSize;
+
+  SStatusRsp *pRsp = rpcMallocCont(contLen);
   if (pRsp == NULL) {
     mnodeDecDnodeRef(pDnode);
     return TSDB_CODE_MND_OUT_OF_MEMORY;
@@ -488,8 +551,8 @@ static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
   pRsp->dnodeCfg.moduleStatus = htonl((int32_t)pDnode->isMgmt);
   pRsp->dnodeCfg.numOfVnodes = htonl(openVnodes);
   tstrncpy(pRsp->dnodeCfg.clusterId, mnodeGetClusterId(), TSDB_CLUSTER_ID_LEN);
-  SDMVgroupAccess *pAccess = (SDMVgroupAccess *)((char *)pRsp + sizeof(SDMStatusRsp));
-
+  SVgroupAccess *pAccess = (SVgroupAccess *)((char *)pRsp + sizeof(SStatusRsp));
+  
   for (int32_t j = 0; j < openVnodes; ++j) {
     SVnodeLoad *pVload = &pStatus->load[j];
     pVload->vgId = htonl(pVload->vgId);
@@ -539,6 +602,9 @@ static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
   
   mnodeDecDnodeRef(pDnode);
 
+  SDnodeEps *pEps = (SDnodeEps *)((char *)pRsp + sizeof(SStatusRsp) + vgAccessSize);
+  mnodeGetDnodeEpsData(pEps, epsSize);
+
   pMsg->rpcRsp.len = contLen;
   pMsg->rpcRsp.rsp =  pRsp;
 
@@ -645,7 +711,7 @@ static int32_t mnodeDropDnodeByEp(char *ep, SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
-  SCMCreateDnodeMsg *pCreate = pMsg->rpcMsg.pCont;
+  SCreateDnodeMsg *pCreate = pMsg->rpcMsg.pCont;
 
   if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
     return TSDB_CODE_MND_NO_RIGHTS;
@@ -655,7 +721,7 @@ static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessDropDnodeMsg(SMnodeMsg *pMsg) {
-  SCMDropDnodeMsg *pDrop = pMsg->rpcMsg.pCont;
+  SDropDnodeMsg *pDrop = pMsg->rpcMsg.pCont;
 
   if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
     return TSDB_CODE_MND_NO_RIGHTS;
diff --git a/src/mnode/src/mnodeMnode.c b/src/mnode/src/mnodeMnode.c
index 89b2f50b73..5a1825a2a3 100644
--- a/src/mnode/src/mnodeMnode.c
+++ b/src/mnode/src/mnodeMnode.c
@@ -38,7 +38,7 @@ static void *        tsMnodeSdb = NULL;
 static int32_t       tsMnodeUpdateSize = 0;
 static SRpcEpSet     tsMnodeEpSetForShell;
 static SRpcEpSet     tsMnodeEpSetForPeer;
-static SDMMnodeInfos tsMnodeInfos;
+static SMnodeInfos   tsMnodeInfos;
 static int32_t mnodeGetMnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
 static int32_t mnodeRetrieveMnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);
 
@@ -70,8 +70,9 @@ static int32_t mnodeMnodeActionInsert(SSdbOper *pOper) {
 
   pDnode->isMgmt = true;
   mnodeDecDnodeRef(pDnode);
-  
-  mInfo("mnode:%d, fqdn:%s ep:%s port:%d, do insert action", pMnode->mnodeId, pDnode->dnodeFqdn, pDnode->dnodeEp, pDnode->dnodePort);
+
+  mInfo("mnode:%d, fqdn:%s ep:%s port:%u, do insert action", pMnode->mnodeId, pDnode->dnodeFqdn, pDnode->dnodeEp,
+        pDnode->dnodePort);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -202,7 +203,7 @@ void mnodeUpdateMnodeEpSet() {
 
   memset(&tsMnodeEpSetForShell, 0, sizeof(SRpcEpSet));
   memset(&tsMnodeEpSetForPeer, 0, sizeof(SRpcEpSet));
-  memset(&tsMnodeInfos, 0, sizeof(SDMMnodeInfos));
+  memset(&tsMnodeInfos, 0, sizeof(SMnodeInfos));
 
   int32_t index = 0;
   void *  pIter = NULL;
@@ -221,8 +222,8 @@ void mnodeUpdateMnodeEpSet() {
       tsMnodeEpSetForPeer.port[index] = htons(pDnode->dnodePort + TSDB_PORT_DNODEDNODE);
       mDebug("mnode:%d, for peer fqdn:%s %d", pDnode->dnodeId, tsMnodeEpSetForPeer.fqdn[index], htons(tsMnodeEpSetForPeer.port[index]));
 
-      tsMnodeInfos.nodeInfos[index].nodeId = htonl(pMnode->mnodeId);
-      strcpy(tsMnodeInfos.nodeInfos[index].nodeEp, pDnode->dnodeEp);
+      tsMnodeInfos.mnodeInfos[index].mnodeId = htonl(pMnode->mnodeId);
+      strcpy(tsMnodeInfos.mnodeInfos[index].mnodeEp, pDnode->dnodeEp);
 
       if (pMnode->role == TAOS_SYNC_ROLE_MASTER) {
         tsMnodeEpSetForShell.inUse = index;
@@ -238,7 +239,7 @@ void mnodeUpdateMnodeEpSet() {
     mnodeDecMnodeRef(pMnode);
   }
 
-  tsMnodeInfos.nodeNum = index;
+  tsMnodeInfos.mnodeNum = index;
   tsMnodeEpSetForShell.numOfEps = index;
   tsMnodeEpSetForPeer.numOfEps = index;
 
@@ -260,19 +261,19 @@ void mnodeGetMnodeEpSetForShell(SRpcEpSet *epSet) {
 }
 
 char* mnodeGetMnodeMasterEp() {
-  return tsMnodeInfos.nodeInfos[tsMnodeInfos.inUse].nodeEp;
+  return tsMnodeInfos.mnodeInfos[tsMnodeInfos.inUse].mnodeEp;
 }
 
 void mnodeGetMnodeInfos(void *mnodeInfos) {
   mnodeMnodeRdLock();
-  *(SDMMnodeInfos *)mnodeInfos = tsMnodeInfos;
+  *(SMnodeInfos *)mnodeInfos = tsMnodeInfos;
   mnodeMnodeUnLock();
 }
 
 static int32_t mnodeSendCreateMnodeMsg(int32_t dnodeId, char *dnodeEp) {
   mDebug("dnode:%d, send create mnode msg to dnode %s", dnodeId, dnodeEp);
 
-  SMDCreateMnodeMsg *pCreate = rpcMallocCont(sizeof(SMDCreateMnodeMsg));
+  SCreateMnodeMsg *pCreate = rpcMallocCont(sizeof(SCreateMnodeMsg));
   if (pCreate == NULL) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   } else {
@@ -280,21 +281,21 @@ static int32_t mnodeSendCreateMnodeMsg(int32_t dnodeId, char *dnodeEp) {
     tstrncpy(pCreate->dnodeEp, dnodeEp, sizeof(pCreate->dnodeEp));
     pCreate->mnodes = tsMnodeInfos;
     bool found = false;
-    for (int i = 0; i < pCreate->mnodes.nodeNum; ++i) {
-      if (pCreate->mnodes.nodeInfos[i].nodeId == htonl(dnodeId)) {
+    for (int i = 0; i < pCreate->mnodes.mnodeNum; ++i) {
+      if (pCreate->mnodes.mnodeInfos[i].mnodeId == htonl(dnodeId)) {
         found = true;
       }
     }
     if (!found) {
-      pCreate->mnodes.nodeInfos[pCreate->mnodes.nodeNum].nodeId = htonl(dnodeId);
-      tstrncpy(pCreate->mnodes.nodeInfos[pCreate->mnodes.nodeNum].nodeEp, dnodeEp, sizeof(pCreate->dnodeEp));
-      pCreate->mnodes.nodeNum++;
+      pCreate->mnodes.mnodeInfos[pCreate->mnodes.mnodeNum].mnodeId = htonl(dnodeId);
+      tstrncpy(pCreate->mnodes.mnodeInfos[pCreate->mnodes.mnodeNum].mnodeEp, dnodeEp, sizeof(pCreate->dnodeEp));
+      pCreate->mnodes.mnodeNum++;
     }
   }
 
   SRpcMsg rpcMsg = {0};
   rpcMsg.pCont = pCreate;
-  rpcMsg.contLen = sizeof(SMDCreateMnodeMsg);
+  rpcMsg.contLen = sizeof(SCreateMnodeMsg);
   rpcMsg.msgType = TSDB_MSG_TYPE_MD_CREATE_MNODE;
 
   SRpcMsg   rpcRsp = {0};
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index c29d1ec0b7..9831a95c5f 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -280,7 +280,7 @@ static int32_t mnodeRetrieveConns(SShowObj *pShow, char *data, int32_t rows, voi
 }
 
 // not thread safe, need optimized
-int32_t mnodeSaveQueryStreamList(SConnObj *pConn, SCMHeartBeatMsg *pHBMsg) {
+int32_t mnodeSaveQueryStreamList(SConnObj *pConn, SHeartBeatMsg *pHBMsg) {
   pConn->numOfQueries = htonl(pHBMsg->numOfQueries);
   if (pConn->numOfQueries > 0) {
     if (pConn->pQueries == NULL) {
@@ -561,7 +561,7 @@ static int32_t mnodeProcessKillQueryMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
   if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
-  SCMKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
+  SKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
   mInfo("kill query msg is received, queryId:%s", pKill->queryId);
 
   const char delim = ':';
@@ -592,7 +592,7 @@ static int32_t mnodeProcessKillStreamMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
   if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
-  SCMKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
+  SKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
   mInfo("kill stream msg is received, streamId:%s", pKill->queryId);
 
   const char delim = ':';
@@ -623,7 +623,7 @@ static int32_t mnodeProcessKillConnectionMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
   if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
-  SCMKillConnMsg *pKill = pMsg->rpcMsg.pCont;
+  SKillConnMsg *pKill = pMsg->rpcMsg.pCont;
   int32_t connId = atoi(pKill->queryId);
   SConnObj *pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
   if (pConn == NULL) {
diff --git a/src/mnode/src/mnodeSdb.c b/src/mnode/src/mnodeSdb.c
index 8c61c61a10..8fb0b33060 100644
--- a/src/mnode/src/mnodeSdb.c
+++ b/src/mnode/src/mnodeSdb.c
@@ -175,7 +175,7 @@ static void *sdbGetTableFromId(int32_t tableId) {
 }
 
 static int32_t sdbInitWal() {
-  SWalCfg walCfg = {.walLevel = 2, .wals = 2, .keep = 1, .fsyncPeriod = 0};
+  SWalCfg walCfg = {.vgId = 1, .walLevel = 2, .wals = 2, .keep = 1, .fsyncPeriod = 0};
   char temp[TSDB_FILENAME_LEN];
   sprintf(temp, "%s/wal", tsMnodeDir);
   tsSdbObj.wal = walOpen(temp, &walCfg);
@@ -237,8 +237,8 @@ static uint32_t sdbGetFileInfo(void *ahandle, char *name, uint32_t *index, uint3
   return 0;
 }
 
-static int sdbGetWalInfo(void *ahandle, char *name, uint32_t *index) {
-  return walGetWalFile(tsSdbObj.wal, name, index);
+static int32_t sdbGetWalInfo(void *ahandle, char *fileName, int64_t *fileId) {
+  return walGetWalFile(tsSdbObj.wal, fileName, fileId);
 }
 
 static void sdbNotifyRole(void *ahandle, int8_t role) {
@@ -312,7 +312,7 @@ void sdbUpdateAsync() {
 }
 
 void sdbUpdateSync(void *pMnodes) {
-  SDMMnodeInfos *mnodes = pMnodes;
+  SMnodeInfos *mnodes = pMnodes;
   if (!mnodeIsRunning()) {
     mDebug("mnode not start yet, update sync config later");
     return;
@@ -346,10 +346,10 @@ void sdbUpdateSync(void *pMnodes) {
     syncCfg.replica = index;
     mDebug("mnodes info not input, use infos in sdb, numOfMnodes:%d", syncCfg.replica);
   } else {
-    for (index = 0; index < mnodes->nodeNum; ++index) {
-      SDMMnodeInfo *node = &mnodes->nodeInfos[index];
-      syncCfg.nodeInfo[index].nodeId = node->nodeId;
-      taosGetFqdnPortFromEp(node->nodeEp, syncCfg.nodeInfo[index].nodeFqdn, &syncCfg.nodeInfo[index].nodePort);
+    for (index = 0; index < mnodes->mnodeNum; ++index) {
+      SMnodeInfo *node = &mnodes->mnodeInfos[index];
+      syncCfg.nodeInfo[index].nodeId = node->mnodeId;
+      taosGetFqdnPortFromEp(node->mnodeEp, syncCfg.nodeInfo[index].nodeFqdn, &syncCfg.nodeInfo[index].nodePort);
       syncCfg.nodeInfo[index].nodePort += TSDB_PORT_SYNC;
     }
     syncCfg.replica = index;
diff --git a/src/mnode/src/mnodeShow.c b/src/mnode/src/mnodeShow.c
index 655fe71259..9cdf81d5a3 100644
--- a/src/mnode/src/mnodeShow.c
+++ b/src/mnode/src/mnodeShow.c
@@ -110,7 +110,7 @@ static char *mnodeGetShowType(int32_t showType) {
 }
 
 static int32_t mnodeProcessShowMsg(SMnodeMsg *pMsg) {
-  SCMShowMsg *pShowMsg = pMsg->rpcMsg.pCont;
+  SShowMsg *pShowMsg = pMsg->rpcMsg.pCont;
   if (pShowMsg->type >= TSDB_MGMT_TABLE_MAX) {
     return TSDB_CODE_MND_INVALID_MSG_TYPE;
   }
@@ -132,8 +132,8 @@ static int32_t mnodeProcessShowMsg(SMnodeMsg *pMsg) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   }
 
-  int32_t size = sizeof(SCMShowRsp) + sizeof(SSchema) * TSDB_MAX_COLUMNS + TSDB_EXTRA_PAYLOAD_SIZE;
-  SCMShowRsp *pShowRsp = rpcMallocCont(size);
+  int32_t size = sizeof(SShowRsp) + sizeof(SSchema) * TSDB_MAX_COLUMNS + TSDB_EXTRA_PAYLOAD_SIZE;
+  SShowRsp *pShowRsp = rpcMallocCont(size);
   if (pShowRsp == NULL) {
     mnodeReleaseShowObj(pShow, true);
     return TSDB_CODE_MND_OUT_OF_MEMORY;
@@ -146,7 +146,7 @@ static int32_t mnodeProcessShowMsg(SMnodeMsg *pMsg) {
 
   if (code == TSDB_CODE_SUCCESS) {
     pMsg->rpcRsp.rsp = pShowRsp;
-    pMsg->rpcRsp.len = sizeof(SCMShowRsp) + sizeof(SSchema) * pShow->numOfColumns;
+    pMsg->rpcRsp.len = sizeof(SShowRsp) + sizeof(SSchema) * pShow->numOfColumns;
     mnodeReleaseShowObj(pShow, false);
     return TSDB_CODE_SUCCESS;
   } else {
@@ -232,12 +232,12 @@ static int32_t mnodeProcessRetrieveMsg(SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessHeartBeatMsg(SMnodeMsg *pMsg) {
-  SCMHeartBeatRsp *pRsp = (SCMHeartBeatRsp *) rpcMallocCont(sizeof(SCMHeartBeatRsp));
+  SHeartBeatRsp *pRsp = (SHeartBeatRsp *)rpcMallocCont(sizeof(SHeartBeatRsp));
   if (pRsp == NULL) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   }
 
-  SCMHeartBeatMsg *pHBMsg = pMsg->rpcMsg.pCont;
+  SHeartBeatMsg *pHBMsg = pMsg->rpcMsg.pCont;
   if (taosCheckVersion(pHBMsg->clientVer, version, 3) != TSDB_CODE_SUCCESS) {
     return TSDB_CODE_TSC_INVALID_VERSION;  // todo change the error code
   }
@@ -280,15 +280,15 @@ static int32_t mnodeProcessHeartBeatMsg(SMnodeMsg *pMsg) {
   mnodeGetMnodeEpSetForShell(&pRsp->epSet);
 
   pMsg->rpcRsp.rsp = pRsp;
-  pMsg->rpcRsp.len = sizeof(SCMHeartBeatRsp);
+  pMsg->rpcRsp.len = sizeof(SHeartBeatRsp);
 
   mnodeReleaseConn(pConn);
   return TSDB_CODE_SUCCESS;
 }
 
 static int32_t mnodeProcessConnectMsg(SMnodeMsg *pMsg) {
-  SCMConnectMsg *pConnectMsg = pMsg->rpcMsg.pCont;
-  SCMConnectRsp *pConnectRsp = NULL;
+  SConnectMsg *pConnectMsg = pMsg->rpcMsg.pCont;
+  SConnectRsp *pConnectRsp = NULL;
   int32_t code = TSDB_CODE_SUCCESS;
 
   SRpcConnInfo connInfo = {0};
@@ -324,7 +324,7 @@ static int32_t mnodeProcessConnectMsg(SMnodeMsg *pMsg) {
     mnodeDecDbRef(pDb);
   }
 
-  pConnectRsp = rpcMallocCont(sizeof(SCMConnectRsp));
+  pConnectRsp = rpcMallocCont(sizeof(SConnectRsp));
   if (pConnectRsp == NULL) {
     code = TSDB_CODE_MND_OUT_OF_MEMORY;
     goto connect_over;
@@ -353,14 +353,14 @@ connect_over:
   } else {
     mLInfo("user:%s login from %s, result:%s", connInfo.user, taosIpStr(connInfo.clientIp), tstrerror(code));
     pMsg->rpcRsp.rsp = pConnectRsp;
-    pMsg->rpcRsp.len = sizeof(SCMConnectRsp);
+    pMsg->rpcRsp.len = sizeof(SConnectRsp);
   }
 
   return code;
 }
 
 static int32_t mnodeProcessUseMsg(SMnodeMsg *pMsg) {
-  SCMUseDbMsg *pUseDbMsg = pMsg->rpcMsg.pCont;
+  SUseDbMsg *pUseDbMsg = pMsg->rpcMsg.pCont;
 
   int32_t code = TSDB_CODE_SUCCESS;
   if (pMsg->pDb == NULL) pMsg->pDb = mnodeGetDb(pUseDbMsg->db);
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index 82a062169a..28dc2c6cff 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -778,7 +778,7 @@ static int32_t mnodeProcessDropTableMsg(SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessTableMetaMsg(SMnodeMsg *pMsg) {
-  SCMTableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
+  STableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
   pInfo->createFlag = htons(pInfo->createFlag);
   mDebug("app:%p:%p, table:%s, table meta msg is received from thandle:%p, createFlag:%d", pMsg->rpcMsg.ahandle, pMsg,
          pInfo->tableId, pMsg->rpcMsg.handle, pInfo->createFlag);
@@ -915,8 +915,8 @@ static int32_t mnodeProcessDropSuperTableMsg(SMnodeMsg *pMsg) {
       SVgObj *pVgroup = mnodeGetVgroup(*pVgId);
       if (pVgroup == NULL) break;
 
-      SMDDropSTableMsg *pDrop = rpcMallocCont(sizeof(SMDDropSTableMsg));
-      pDrop->contLen = htonl(sizeof(SMDDropSTableMsg));
+      SDropSTableMsg *pDrop = rpcMallocCont(sizeof(SDropSTableMsg));
+      pDrop->contLen = htonl(sizeof(SDropSTableMsg));
       pDrop->vgId = htonl(pVgroup->vgId);
       pDrop->uid = htobe64(pStable->uid);
       mnodeExtractTableName(pStable->info.tableId, pDrop->tableId);
@@ -924,7 +924,7 @@ static int32_t mnodeProcessDropSuperTableMsg(SMnodeMsg *pMsg) {
       mInfo("app:%p:%p, stable:%s, send drop stable msg to vgId:%d", pMsg->rpcMsg.ahandle, pMsg, pStable->info.tableId,
              pVgroup->vgId);
       SRpcEpSet epSet = mnodeGetEpSetFromVgroup(pVgroup);
-      SRpcMsg   rpcMsg = {.pCont = pDrop, .contLen = sizeof(SMDDropSTableMsg), .msgType = TSDB_MSG_TYPE_MD_DROP_STABLE};
+      SRpcMsg   rpcMsg = {.pCont = pDrop, .contLen = sizeof(SDropSTableMsg), .msgType = TSDB_MSG_TYPE_MD_DROP_STABLE};
       dnodeSendMsgToDnode(&epSet, &rpcMsg);
       mnodeDecVgroupRef(pVgroup);
     }
@@ -1472,31 +1472,31 @@ static int32_t mnodeGetSuperTableMeta(SMnodeMsg *pMsg) {
 }
 
 static int32_t mnodeProcessSuperTableVgroupMsg(SMnodeMsg *pMsg) {
-  SCMSTableVgroupMsg *pInfo = pMsg->rpcMsg.pCont;
+  SSTableVgroupMsg *pInfo = pMsg->rpcMsg.pCont;
   int32_t numOfTable = htonl(pInfo->numOfTables);
 
   // reserve space
-  int32_t contLen = sizeof(SCMSTableVgroupRspMsg) + 32 * sizeof(SCMVgroupMsg) + sizeof(SVgroupsMsg);
+  int32_t contLen = sizeof(SSTableVgroupRspMsg) + 32 * sizeof(SVgroupMsg) + sizeof(SVgroupsMsg);
   for (int32_t i = 0; i < numOfTable; ++i) {
-    char *stableName = (char*)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN) * i;
+    char *stableName = (char *)pInfo + sizeof(SSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN)*i;
     SSuperTableObj *pTable = mnodeGetSuperTable(stableName);
     if (pTable != NULL && pTable->vgHash != NULL) {
-      contLen += (taosHashGetSize(pTable->vgHash) * sizeof(SCMVgroupMsg) + sizeof(SVgroupsMsg));
-    } 
-    
+      contLen += (taosHashGetSize(pTable->vgHash) * sizeof(SVgroupMsg) + sizeof(SVgroupsMsg));
+    }
+
     mnodeDecTableRef(pTable);
   }
 
-  SCMSTableVgroupRspMsg *pRsp = rpcMallocCont(contLen);
+  SSTableVgroupRspMsg *pRsp = rpcMallocCont(contLen);
   if (pRsp == NULL) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   }
 
   pRsp->numOfTables = 0;
-  char *msg = (char *)pRsp + sizeof(SCMSTableVgroupRspMsg);
+  char *msg = (char *)pRsp + sizeof(SSTableVgroupRspMsg);
 
   for (int32_t i = 0; i < numOfTable; ++i) {
-    char *          stableName = (char *)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN)*i;
+    char *          stableName = (char *)pInfo + sizeof(SSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN)*i;
     SSuperTableObj *pTable = mnodeGetSuperTable(stableName);
     if (pTable == NULL) {
       mError("app:%p:%p, stable:%s, not exist while get stable vgroup info", pMsg->rpcMsg.ahandle, pMsg, stableName);
@@ -1548,7 +1548,7 @@ static int32_t mnodeProcessSuperTableVgroupMsg(SMnodeMsg *pMsg) {
       pVgroupMsg->numOfVgroups = htonl(vgSize);
 
       // one table is done, try the next table
-      msg += sizeof(SVgroupsMsg) + vgSize * sizeof(SCMVgroupMsg);
+      msg += sizeof(SVgroupsMsg) + vgSize * sizeof(SVgroupMsg);
       pRsp->numOfTables++;
     }
   }
@@ -2146,7 +2146,7 @@ static int32_t mnodeDoGetChildTableMeta(SMnodeMsg *pMsg, STableMetaMsg *pMeta) {
 }
 
 static int32_t mnodeAutoCreateChildTable(SMnodeMsg *pMsg) {
-  SCMTableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
+  STableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
   STagData *pTags = (STagData *)pInfo->tags;
   int32_t tagLen = htonl(pTags->dataLen);
   if (pTags->name[0] == 0) {
@@ -2307,7 +2307,7 @@ static SChildTableObj* mnodeGetTableByPos(int32_t vnode, int32_t tid) {
 static int32_t mnodeProcessTableCfgMsg(SMnodeMsg *pMsg) {
   return TSDB_CODE_COM_OPS_NOT_SUPPORT;
 #if 0  
-  SDMConfigTableMsg *pCfg = pMsg->rpcMsg.pCont;
+  SConfigTableMsg *pCfg = pMsg->rpcMsg.pCont;
   pCfg->dnodeId = htonl(pCfg->dnodeId);
   pCfg->vgId = htonl(pCfg->vgId);
   pCfg->sid = htonl(pCfg->sid);
@@ -2469,7 +2469,7 @@ static void mnodeProcessAlterTableRsp(SRpcMsg *rpcMsg) {
 }
 
 static int32_t mnodeProcessMultiTableMetaMsg(SMnodeMsg *pMsg) {
-  SCMMultiTableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
+  SMultiTableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
   pInfo->numOfTables = htonl(pInfo->numOfTables);
 
   int32_t totalMallocLen = 4 * 1024 * 1024;  // first malloc 4 MB, subsequent reallocation as twice
@@ -2705,7 +2705,7 @@ static int32_t mnodeRetrieveShowTables(SShowObj *pShow, char *data, int32_t rows
 }
 
 static int32_t mnodeProcessAlterTableMsg(SMnodeMsg *pMsg) {
-  SCMAlterTableMsg *pAlter = pMsg->rpcMsg.pCont;
+  SAlterTableMsg *pAlter = pMsg->rpcMsg.pCont;
   mDebug("app:%p:%p, table:%s, alter table msg is received from thandle:%p", pMsg->rpcMsg.ahandle, pMsg,
          pAlter->tableId, pMsg->rpcMsg.handle);
 
diff --git a/src/mnode/src/mnodeUser.c b/src/mnode/src/mnodeUser.c
index 779e252548..8e9d2908c5 100644
--- a/src/mnode/src/mnodeUser.c
+++ b/src/mnode/src/mnodeUser.c
@@ -414,7 +414,7 @@ static int32_t mnodeProcessCreateUserMsg(SMnodeMsg *pMsg) {
   SUserObj *pOperUser = pMsg->pUser;
   
   if (pOperUser->superAuth) {
-    SCMCreateUserMsg *pCreate = pMsg->rpcMsg.pCont;
+    SCreateUserMsg *pCreate = pMsg->rpcMsg.pCont;
     return mnodeCreateUser(pOperUser->pAcct, pCreate->user, pCreate->pass, pMsg);
   } else {
     mError("user:%s, no rights to create user", pOperUser->user);
@@ -426,7 +426,7 @@ static int32_t mnodeProcessAlterUserMsg(SMnodeMsg *pMsg) {
   int32_t code;
   SUserObj *pOperUser = pMsg->pUser;
   
-  SCMAlterUserMsg *pAlter = pMsg->rpcMsg.pCont;
+  SAlterUserMsg *pAlter = pMsg->rpcMsg.pCont;
   SUserObj *pUser = mnodeGetUser(pAlter->user);
   if (pUser == NULL) {
     return TSDB_CODE_MND_INVALID_USER;
@@ -514,7 +514,7 @@ static int32_t mnodeProcessDropUserMsg(SMnodeMsg *pMsg) {
   int32_t code;
   SUserObj *pOperUser = pMsg->pUser;
 
-  SCMDropUserMsg *pDrop = pMsg->rpcMsg.pCont;
+  SDropUserMsg *pDrop = pMsg->rpcMsg.pCont;
   SUserObj *pUser = mnodeGetUser(pDrop->user);
   if (pUser == NULL) {
     return TSDB_CODE_MND_INVALID_USER;
@@ -604,11 +604,11 @@ int32_t mnodeRetriveAuth(char *user, char *spi, char *encrypt, char *secret, cha
 }
 
 static int32_t mnodeProcessAuthMsg(SMnodeMsg *pMsg) {
-  SDMAuthMsg *pAuthMsg = pMsg->rpcMsg.pCont;
-  SDMAuthRsp *pAuthRsp = rpcMallocCont(sizeof(SDMAuthRsp));
+  SAuthMsg *pAuthMsg = pMsg->rpcMsg.pCont;
+  SAuthRsp *pAuthRsp = rpcMallocCont(sizeof(SAuthRsp));
   
   pMsg->rpcRsp.rsp = pAuthRsp;
-  pMsg->rpcRsp.len = sizeof(SDMAuthRsp);
+  pMsg->rpcRsp.len = sizeof(SAuthRsp);
   
   return mnodeRetriveAuth(pAuthMsg->user, &pAuthRsp->spi, &pAuthRsp->encrypt, pAuthRsp->secret, pAuthRsp->ckey);
 }
diff --git a/src/mnode/src/mnodeVgroup.c b/src/mnode/src/mnodeVgroup.c
index 83dd80d533..d3fa9a43ab 100644
--- a/src/mnode/src/mnodeVgroup.c
+++ b/src/mnode/src/mnodeVgroup.c
@@ -818,11 +818,11 @@ void mnodeRemoveTableFromVgroup(SVgObj *pVgroup, SChildTableObj *pTable) {
   }
 }
 
-static SMDCreateVnodeMsg *mnodeBuildVnodeMsg(SVgObj *pVgroup) {
+static SCreateVnodeMsg *mnodeBuildVnodeMsg(SVgObj *pVgroup) {
   SDbObj *pDb = pVgroup->pDb;
   if (pDb == NULL) return NULL;
 
-  SMDCreateVnodeMsg *pVnode = rpcMallocCont(sizeof(SMDCreateVnodeMsg));
+  SCreateVnodeMsg *pVnode = rpcMallocCont(sizeof(SCreateVnodeMsg));
   if (pVnode == NULL) return NULL;
 
   strcpy(pVnode->db, pVgroup->dbName);
@@ -830,7 +830,7 @@ static SMDCreateVnodeMsg *mnodeBuildVnodeMsg(SVgObj *pVgroup) {
   //TODO: dynamic alloc tables in tsdb
   maxTables = MAX(10000, tsMaxTablePerVnode);
 
-  SMDVnodeCfg *pCfg = &pVnode->cfg;
+  SVnodeCfg *pCfg = &pVnode->cfg;
   pCfg->vgId                = htonl(pVgroup->vgId);
   pCfg->cfgVersion          = htonl(pDb->cfgVersion);
   pCfg->cacheBlockSize      = htonl(pDb->cfg.cacheBlockSize);
@@ -852,7 +852,7 @@ static SMDCreateVnodeMsg *mnodeBuildVnodeMsg(SVgObj *pVgroup) {
   pCfg->quorum              = pDb->cfg.quorum;
   pCfg->update              = pDb->cfg.update;
   
-  SMDVnodeDesc *pNodes = pVnode->nodes;
+  SVnodeDesc *pNodes = pVnode->nodes;
   for (int32_t j = 0; j < pVgroup->numOfVnodes; ++j) {
     SDnodeObj *pDnode = pVgroup->vnodeGid[j].pDnode;
     if (pDnode != NULL) {
@@ -887,11 +887,11 @@ SRpcEpSet mnodeGetEpSetFromIp(char *ep) {
 }
 
 static void mnodeSendAlterVnodeMsg(SVgObj *pVgroup, SRpcEpSet *epSet) {
-  SMDAlterVnodeMsg *pAlter = mnodeBuildVnodeMsg(pVgroup);
+  SAlterVnodeMsg *pAlter = mnodeBuildVnodeMsg(pVgroup);
   SRpcMsg rpcMsg = {
     .ahandle = NULL,
     .pCont   = pAlter,
-    .contLen = pAlter ? sizeof(SMDAlterVnodeMsg) : 0,
+    .contLen = pAlter ? sizeof(SAlterVnodeMsg) : 0,
     .code    = 0,
     .msgType = TSDB_MSG_TYPE_MD_ALTER_VNODE
   };
@@ -910,11 +910,11 @@ void mnodeSendAlterVgroupMsg(SVgObj *pVgroup) {
 }
 
 static void mnodeSendCreateVnodeMsg(SVgObj *pVgroup, SRpcEpSet *epSet, void *ahandle) {
-  SMDCreateVnodeMsg *pCreate = mnodeBuildVnodeMsg(pVgroup);
+  SCreateVnodeMsg *pCreate = mnodeBuildVnodeMsg(pVgroup);
   SRpcMsg rpcMsg = {
     .ahandle = ahandle,
     .pCont   = pCreate,
-    .contLen = pCreate ? sizeof(SMDCreateVnodeMsg) : 0,
+    .contLen = pCreate ? sizeof(SCreateVnodeMsg) : 0,
     .code    = 0,
     .msgType = TSDB_MSG_TYPE_MD_CREATE_VNODE
   };
@@ -983,8 +983,8 @@ static void mnodeProcessCreateVnodeRsp(SRpcMsg *rpcMsg) {
   }
 }
 
-static SMDDropVnodeMsg *mnodeBuildDropVnodeMsg(int32_t vgId) {
-  SMDDropVnodeMsg *pDrop = rpcMallocCont(sizeof(SMDDropVnodeMsg));
+static SDropVnodeMsg *mnodeBuildDropVnodeMsg(int32_t vgId) {
+  SDropVnodeMsg *pDrop = rpcMallocCont(sizeof(SDropVnodeMsg));
   if (pDrop == NULL) return NULL;
 
   pDrop->vgId = htonl(vgId);
@@ -992,11 +992,11 @@ static SMDDropVnodeMsg *mnodeBuildDropVnodeMsg(int32_t vgId) {
 }
 
 void mnodeSendDropVnodeMsg(int32_t vgId, SRpcEpSet *epSet, void *ahandle) {
-  SMDDropVnodeMsg *pDrop = mnodeBuildDropVnodeMsg(vgId);
+  SDropVnodeMsg *pDrop = mnodeBuildDropVnodeMsg(vgId);
   SRpcMsg rpcMsg = {
       .ahandle = ahandle,
       .pCont   = pDrop,
-      .contLen = pDrop ? sizeof(SMDDropVnodeMsg) : 0,
+      .contLen = pDrop ? sizeof(SDropVnodeMsg) : 0,
       .code    = 0,
       .msgType = TSDB_MSG_TYPE_MD_DROP_VNODE
   };
@@ -1045,7 +1045,7 @@ static void mnodeProcessDropVnodeRsp(SRpcMsg *rpcMsg) {
 }
 
 static int32_t mnodeProcessVnodeCfgMsg(SMnodeMsg *pMsg) {
-  SDMConfigVnodeMsg *pCfg = pMsg->rpcMsg.pCont;
+  SConfigVnodeMsg *pCfg = pMsg->rpcMsg.pCont;
   pCfg->dnodeId = htonl(pCfg->dnodeId);
   pCfg->vgId    = htonl(pCfg->vgId);
 
diff --git a/src/os/src/detail/osFile.c b/src/os/src/detail/osFile.c
index 8f055dd812..e0fa32c7d2 100644
--- a/src/os/src/detail/osFile.c
+++ b/src/os/src/detail/osFile.c
@@ -15,16 +15,21 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
+#include "tglobal.h"
 
 #ifndef TAOS_OS_FUNC_FILE_GETTMPFILEPATH
 void taosGetTmpfilePath(const char *fileNamePrefix, char *dstPath) {
   const char *tdengineTmpFileNamePrefix = "tdengine-";
 
   char  tmpPath[PATH_MAX];
-  char *tmpDir = "/tmp/";
+  int32_t len = strlen(tsTempDir);
+  memcpy(tmpPath, tsTempDir, len);
 
-  strcpy(tmpPath, tmpDir);
-  strcat(tmpPath, tdengineTmpFileNamePrefix);
+  if (tmpPath[len - 1] != '/') {
+      tmpPath[len++] = '/';
+  }
+
+  strcpy(tmpPath + len, tdengineTmpFileNamePrefix);
   if (strlen(tmpPath) + strlen(fileNamePrefix) + strlen("-%d-%s") < PATH_MAX) {
     strcat(tmpPath, fileNamePrefix);
     strcat(tmpPath, "-%d-%s");
diff --git a/src/os/src/windows/wEnv.c b/src/os/src/windows/wEnv.c
index 8110a19490..19351eb7c9 100644
--- a/src/os/src/windows/wEnv.c
+++ b/src/os/src/windows/wEnv.c
@@ -46,5 +46,16 @@ void osInit() {
   strcpy(tsDnodeDir, "");
   strcpy(tsMnodeDir, "");  
   strcpy(tsOsName, "Windows");
+
+  const char *tmpDir = getenv("tmp");
+  if (tmpDir != NULL) {
+    tmpDir = getenv("temp");
+  }
+  if (tmpDir != NULL) {
+    strcpy(tsTempDir, tmpDir);
+  } else {
+    strcpy(tsTempDir, "C:\\Windows\\Temp");
+  }
+  
   taosWinSocketInit();
 }
diff --git a/src/os/src/windows/wFile.c b/src/os/src/windows/wFile.c
index 5549c078a5..fa835ae820 100644
--- a/src/os/src/windows/wFile.c
+++ b/src/os/src/windows/wFile.c
@@ -16,17 +16,20 @@
 #define _DEFAULT_SOURCE
 #include "os.h"
 #include "tulog.h"
+#include "tglobal.h"
 
 void taosGetTmpfilePath(const char *fileNamePrefix, char *dstPath) {
   const char* tdengineTmpFileNamePrefix = "tdengine-";
-    char tmpPath[PATH_MAX];
+  char tmpPath[PATH_MAX];
 
-  char *tmpDir = getenv("tmp");
-  if (tmpDir == NULL) {
-    tmpDir = "";
+  int32_t len = (int32_t)strlen(tsTempDir);
+  memcpy(tmpPath, tsTempDir, len);
+
+  if (tmpPath[len - 1] != '/' && tmpPath[len - 1] != '\\') {
+      tmpPath[len++] = '\\';
   }
-  
-  strcpy(tmpPath, tmpDir);
+
+  strcpy(tmpPath + len, tdengineTmpFileNamePrefix);
   strcat(tmpPath, tdengineTmpFileNamePrefix);
   if (strlen(tmpPath) + strlen(fileNamePrefix) + strlen("-%d-%s") < PATH_MAX) {
     strcat(tmpPath, fileNamePrefix);
diff --git a/src/rpc/src/rpcMain.c b/src/rpc/src/rpcMain.c
index 1dfd87ff3a..d01c34c810 100644
--- a/src/rpc/src/rpcMain.c
+++ b/src/rpc/src/rpcMain.c
@@ -341,7 +341,7 @@ void *rpcMallocCont(int contLen) {
     tError("failed to malloc msg, size:%d", size);
     return NULL;
   } else {
-    tTrace("malloc mem: %p", start);
+    tTrace("malloc mem:%p size:%d", start, size);
   }
 
   return start + sizeof(SRpcReqContext) + sizeof(SRpcHead);
@@ -557,10 +557,7 @@ void rpcCancelRequest(void *handle) {
   int code = taosAcquireRef(tsRpcRefId, pContext);
   if (code < 0) return;
 
-  if (pContext->pConn) {
-    tDebug("%s, app tries to cancel request", pContext->pConn->info);
-    rpcCloseConn(pContext->pConn);
-  }
+  rpcCloseConn(pContext->pConn);
 
   taosReleaseRef(tsRpcRefId, pContext);
 }
@@ -655,6 +652,7 @@ static void rpcReleaseConn(SRpcConn *pConn) {
 
 static void rpcCloseConn(void *thandle) {
   SRpcConn *pConn = (SRpcConn *)thandle;
+  if (pConn == NULL) return;
 
   rpcLockConn(pConn);
 
@@ -1026,6 +1024,7 @@ static void rpcProcessBrokenLink(SRpcConn *pConn) {
   if (pConn->outType) {
     SRpcReqContext *pContext = pConn->pContext;
     pContext->code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
+    pContext->pConn = NULL;
     pConn->pReqMsg = NULL;
     taosTmrStart(rpcProcessConnError, 0, pContext, pRpc->tmrCtrl);
   }
@@ -1135,6 +1134,7 @@ static void rpcProcessIncomingMsg(SRpcConn *pConn, SRpcHead *pHead, SRpcReqConte
     // it's a response
     rpcMsg.handle = pContext;
     rpcMsg.ahandle = pContext->ahandle;
+    pContext->pConn = NULL;
 
     // for UDP, port may be changed by server, the port in epSet shall be used for cache
     if (pHead->code != TSDB_CODE_RPC_TOO_SLOW) {
@@ -1370,6 +1370,7 @@ static void rpcProcessRetryTimer(void *param, void *tmrId) {
       tDebug("%s, failed to send msg:%s to %s:%hu", pConn->info, taosMsg[pConn->outType], pConn->peerFqdn, pConn->peerPort);
       if (pConn->pContext) {
         pConn->pContext->code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
+        pConn->pContext->pConn = NULL;
         pConn->pReqMsg = NULL;
         taosTmrStart(rpcProcessConnError, 0, pConn->pContext, pRpc->tmrCtrl);
         rpcReleaseConn(pConn);
@@ -1478,7 +1479,7 @@ static SRpcHead *rpcDecompressRpcMsg(SRpcHead *pHead) {
       pNewHead->msgLen = rpcMsgLenFromCont(origLen);
       rpcFreeMsg(pHead); // free the compressed message buffer
       pHead = pNewHead; 
-      tTrace("decomp malloc mem: %p", temp);
+      tTrace("decomp malloc mem:%p", temp);
     } else {
       tError("failed to allocate memory to decompress msg, contLen:%d", contLen);
     }
diff --git a/src/rpc/src/rpcTcp.c b/src/rpc/src/rpcTcp.c
index bc8d360d39..c6de398608 100644
--- a/src/rpc/src/rpcTcp.c
+++ b/src/rpc/src/rpcTcp.c
@@ -437,12 +437,13 @@ static int taosReadTcpData(SFdObj *pFdObj, SRecvInfo *pInfo) {
   }
 
   msgLen = (int32_t)htonl((uint32_t)rpcHead.msgLen);
-  buffer = malloc(msgLen + tsRpcOverhead);
+  int32_t size = msgLen + tsRpcOverhead;
+  buffer = malloc(size);
   if (NULL == buffer) {
     tError("%s %p TCP malloc(size:%d) fail", pThreadObj->label, pFdObj->thandle, msgLen);
     return -1;
   } else {
-    tTrace("TCP malloc mem: %p", buffer);
+    tTrace("TCP malloc mem:%p size:%d", buffer, size);
   }
 
   msg = buffer + tsRpcOverhead;
diff --git a/src/rpc/src/rpcUdp.c b/src/rpc/src/rpcUdp.c
index 6f65304661..9bac2b1c19 100644
--- a/src/rpc/src/rpcUdp.c
+++ b/src/rpc/src/rpcUdp.c
@@ -209,12 +209,13 @@ static void *taosRecvUdpData(void *param) {
       continue;
     }
 
-    char *tmsg = malloc(dataLen + tsRpcOverhead);
+    int32_t size = dataLen + tsRpcOverhead;
+    char *tmsg = malloc(size);
     if (NULL == tmsg) {
       tError("%s failed to allocate memory, size:%" PRId64, pConn->label, (int64_t)dataLen);
       continue;
     } else {
-      tTrace("UDP malloc mem: %p", tmsg);
+      tTrace("UDP malloc mem:%p size:%d", tmsg, size);
     }
 
     tmsg += tsRpcOverhead;  // overhead for SRpcReqContext
diff --git a/src/sync/src/syncRetrieve.c b/src/sync/src/syncRetrieve.c
index 60625d75ec..0137794d18 100644
--- a/src/sync/src/syncRetrieve.c
+++ b/src/sync/src/syncRetrieve.c
@@ -287,7 +287,7 @@ static int syncRetrieveLastWal(SSyncPeer *pPeer, char *name, uint64_t fversion,
   return -1;
 }
 
-static int syncProcessLastWal(SSyncPeer *pPeer, char *wname, uint32_t index) {
+static int syncProcessLastWal(SSyncPeer *pPeer, char *wname, int64_t index) {
   SSyncNode *pNode = pPeer->pSyncNode;
   int        code = -1;
   char       fname[TSDB_FILENAME_LEN * 2];  // full path to wal file
@@ -377,7 +377,7 @@ static int syncRetrieveWal(SSyncPeer *pPeer) {
   int32_t     size;
   struct stat fstat;
   int         code = -1;
-  uint32_t    index = 0;
+  int64_t     index = 0;
 
   while (1) {
     // retrieve wal info
diff --git a/src/sync/test/syncServer.c b/src/sync/test/syncServer.c
index 380b971fa8..0cf752da97 100644
--- a/src/sync/test/syncServer.c
+++ b/src/sync/test/syncServer.c
@@ -254,7 +254,7 @@ uint32_t getFileInfo(void *ahandle, char *name, uint32_t *index, uint32_t eindex
   return magic;
 }
 
-int getWalInfo(void *ahandle, char *name, uint32_t *index) {
+int getWalInfo(void *ahandle, char *name, int64_t *index) {
   struct stat fstat;
   char        aname[280];
 
diff --git a/src/util/inc/talloc.h b/src/util/inc/talloc.h
new file mode 100644
index 0000000000..1fc4d759b0
--- /dev/null
+++ b/src/util/inc/talloc.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_UTIL_ALLOC_H
+#define TDENGINE_UTIL_ALLOC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define TSDB_USE_SYS_MEM
+
+#ifdef TSDB_USE_SYS_MEM
+  #define tmalloc(size) malloc(size)
+  #define tcalloc(size) calloc(1, size)
+  #define trealloc(p, size) realloc(p, size)
+  #define tmemalign(alignment, size) malloc(size)
+  #define tfree(p) free(p)
+  #define tmemzero(p, size) memset(p, 0, size)
+#else
+  void *tmalloc(int32_t size);
+  void *tcalloc(int32_t size);
+  void *trealloc(void *p, int32_t size);
+  void *tmemalign(int32_t alignment, int32_t size);
+  void  tfree(void *p);
+  void  tmemzero(void *p, int32_t size);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/util/src/talloc.c b/src/util/src/talloc.c
new file mode 100644
index 0000000000..d3d8ee8116
--- /dev/null
+++ b/src/util/src/talloc.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "taoserror.h"
+#include "tulog.h"
+#include "talloc.h"
+
+#define TSDB_HAVE_MEMALIGN
+#ifndef TSDB_USE_SYS_MEM
+
+void *tmalloc(int32_t size) {
+  void *p = malloc(size);
+  if (p == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    uError("failed to malloc memory, size:%d reason:%s", size, strerror(errno));
+  }
+
+  return p;
+}
+
+void *tcalloc(int32_t size) {
+  void *p = calloc(1, size);
+  if (p == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    uError("failed to calloc memory, size:%d reason:%s", size, strerror(errno));
+  }
+
+  return p;
+}
+
+void *trealloc(void *p, int32_t size) {
+  p = realloc(p, size);
+  if (p == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    uError("failed to realloc memory, size:%d reason:%s", size, strerror(errno));
+  }
+
+  return p;
+}
+
+void tfree(void *p) { free(p); }
+
+void tmemzero(void *p, int32_t size) { memset(p, 0, size); }
+
+#ifdef TSDB_HAVE_MEMALIGN
+
+void *tmemalign(int32_t alignment, int32_t size) {
+  void *p;
+
+  int err = posix_memalign(&p, alignment, size);
+  if (err) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    uError("failed to memalign memory, alignment:%d size:%d reason:%s", alignment, size, strerror(err));
+    p = NULL;
+  }
+
+  return p;
+}
+
+#else
+
+void *tmemalign(int32_t alignment, int32_t size) { return tmalloc(size); }
+
+#endif
+#endif
\ No newline at end of file
diff --git a/src/util/src/tconfig.c b/src/util/src/tconfig.c
index 0ec55841a0..f449bfb68b 100644
--- a/src/util/src/tconfig.c
+++ b/src/util/src/tconfig.c
@@ -355,7 +355,11 @@ bool taosReadGlobalCfg() {
   fclose(fp);
 
   taosTFree(line);
-  
+
+  if (debugFlag & DEBUG_TRACE || debugFlag & DEBUG_DEBUG || debugFlag & DEBUG_DUMP) {
+    taosSetAllDebugFlag();
+  }
+
   return true;
 }
 
diff --git a/src/wal/inc/walMgmt.h b/src/vnode/inc/vnodeCfg.h
similarity index 82%
rename from src/wal/inc/walMgmt.h
rename to src/vnode/inc/vnodeCfg.h
index a23c7f8ec3..c5887fef5d 100644
--- a/src/wal/inc/walMgmt.h
+++ b/src/vnode/inc/vnodeCfg.h
@@ -13,13 +13,16 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef TDENGINE_WAL_MGMT_H
-#define TDENGINE_WAL_MGMT_H
+#ifndef TDENGINE_VNODE_CFG_H
+#define TDENGINE_VNODE_CFG_H
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+int32_t vnodeReadCfg(SVnodeObj *pVnode);
+int32_t vnodeWriteCfg(SCreateVnodeMsg *pVnodeCfg);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/vnode/inc/vnodeVersion.h b/src/vnode/inc/vnodeVersion.h
new file mode 100644
index 0000000000..1d086cb21f
--- /dev/null
+++ b/src/vnode/inc/vnodeVersion.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_VNODE_VERSION_H
+#define TDENGINE_VNODE_VERSION_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int32_t vnodeReadVersion(SVnodeObj *pVnode);
+int32_t vnodeSaveVersion(SVnodeObj *pVnode);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/vnode/src/vnodeCfg.c b/src/vnode/src/vnodeCfg.c
new file mode 100644
index 0000000000..f0040f8cdf
--- /dev/null
+++ b/src/vnode/src/vnodeCfg.c
@@ -0,0 +1,326 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "taosmsg.h"
+#include "taoserror.h"
+#include "cJSON.h"
+#include "tglobal.h"
+#include "tsdb.h"
+#include "dnode.h"
+#include "vnodeInt.h"
+#include "vnodeVersion.h"
+#include "vnodeCfg.h"
+
+static void vnodeLoadCfg(SVnodeObj *pVnode, SCreateVnodeMsg* vnodeMsg) {
+  strcpy(pVnode->db, vnodeMsg->db);
+  pVnode->cfgVersion = vnodeMsg->cfg.cfgVersion;
+  pVnode->tsdbCfg.cacheBlockSize = vnodeMsg->cfg.cacheBlockSize;
+  pVnode->tsdbCfg.totalBlocks = vnodeMsg->cfg.totalBlocks;
+  pVnode->tsdbCfg.daysPerFile = vnodeMsg->cfg.daysPerFile;
+  pVnode->tsdbCfg.keep = vnodeMsg->cfg.daysToKeep;
+  pVnode->tsdbCfg.keep1 = vnodeMsg->cfg.daysToKeep1;
+  pVnode->tsdbCfg.keep2 = vnodeMsg->cfg.daysToKeep2;
+  pVnode->tsdbCfg.minRowsPerFileBlock = vnodeMsg->cfg.minRowsPerFileBlock;
+  pVnode->tsdbCfg.maxRowsPerFileBlock = vnodeMsg->cfg.maxRowsPerFileBlock;
+  pVnode->tsdbCfg.precision = vnodeMsg->cfg.precision;
+  pVnode->tsdbCfg.compression = vnodeMsg->cfg.compression;
+  pVnode->walCfg.walLevel = vnodeMsg->cfg.walLevel;
+  pVnode->walCfg.fsyncPeriod = vnodeMsg->cfg.fsyncPeriod;
+  pVnode->walCfg.wals = vnodeMsg->cfg.wals;
+  pVnode->walCfg.keep = 0;
+  pVnode->syncCfg.replica = vnodeMsg->cfg.replications;
+  pVnode->syncCfg.quorum = vnodeMsg->cfg.quorum;
+
+  for (int i = 0; i < pVnode->syncCfg.replica; ++i) {
+    SVnodeDesc *node = &vnodeMsg->nodes[i];
+    pVnode->syncCfg.nodeInfo[i].nodeId = node->nodeId;
+    taosGetFqdnPortFromEp(node->nodeEp, pVnode->syncCfg.nodeInfo[i].nodeFqdn, &pVnode->syncCfg.nodeInfo[i].nodePort);
+    pVnode->syncCfg.nodeInfo[i].nodePort += TSDB_PORT_SYNC;
+  }
+
+  vInfo("vgId:%d, load vnode cfg successfully, replcia:%d", pVnode->vgId, pVnode->syncCfg.replica);
+  for (int32_t i = 0; i < pVnode->syncCfg.replica; i++) {
+    SNodeInfo *node = &pVnode->syncCfg.nodeInfo[i];
+    vInfo("vgId:%d, dnode:%d, %s:%u", pVnode->vgId, node->nodeId, node->nodeFqdn, node->nodePort);
+  }
+}
+
+int32_t vnodeReadCfg(SVnodeObj *pVnode) {
+  int32_t ret = TSDB_CODE_VND_APP_ERROR;
+  int32_t len = 0;
+  int     maxLen = 1000;
+  char *  content = calloc(1, maxLen + 1);
+  cJSON * root = NULL;
+  FILE *  fp = NULL;
+  bool    nodeChanged = false;
+  SCreateVnodeMsg vnodeMsg;
+
+  char file[TSDB_FILENAME_LEN + 30] = {0};
+  sprintf(file, "%s/vnode%d/config.json", tsVnodeDir, pVnode->vgId);
+
+  vnodeMsg.cfg.vgId = pVnode->vgId;
+
+  fp = fopen(file, "r");
+  if (!fp) {
+    vError("vgId:%d, failed to open vnode cfg file:%s to read, error:%s", pVnode->vgId, file, strerror(errno));
+    ret = TAOS_SYSTEM_ERROR(errno);
+    goto PARSE_VCFG_ERROR;
+  }
+
+  len = fread(content, 1, maxLen, fp);
+  if (len <= 0) {
+    vError("vgId:%d, failed to read %s, content is null", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+
+  content[len] = 0;
+  root = cJSON_Parse(content);
+  if (root == NULL) {
+    vError("vgId:%d, failed to read %s, invalid json format", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+
+  cJSON *db = cJSON_GetObjectItem(root, "db");
+  if (!db || db->type != cJSON_String || db->valuestring == NULL) {
+    vError("vgId:%d, failed to read %s, db not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  strcpy(vnodeMsg.db, db->valuestring);
+
+  cJSON *cfgVersion = cJSON_GetObjectItem(root, "cfgVersion");
+  if (!cfgVersion || cfgVersion->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, cfgVersion not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.cfgVersion = cfgVersion->valueint;
+
+  cJSON *cacheBlockSize = cJSON_GetObjectItem(root, "cacheBlockSize");
+  if (!cacheBlockSize || cacheBlockSize->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, cacheBlockSize not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.cacheBlockSize = cacheBlockSize->valueint;
+
+  cJSON *totalBlocks = cJSON_GetObjectItem(root, "totalBlocks");
+  if (!totalBlocks || totalBlocks->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, totalBlocks not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.totalBlocks = totalBlocks->valueint;
+
+  cJSON *daysPerFile = cJSON_GetObjectItem(root, "daysPerFile");
+  if (!daysPerFile || daysPerFile->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, daysPerFile not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.daysPerFile = daysPerFile->valueint;
+
+  cJSON *daysToKeep = cJSON_GetObjectItem(root, "daysToKeep");
+  if (!daysToKeep || daysToKeep->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, daysToKeep not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.daysToKeep = daysToKeep->valueint;
+
+  cJSON *daysToKeep1 = cJSON_GetObjectItem(root, "daysToKeep1");
+  if (!daysToKeep1 || daysToKeep1->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, daysToKeep1 not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.daysToKeep1 = daysToKeep1->valueint;
+
+  cJSON *daysToKeep2 = cJSON_GetObjectItem(root, "daysToKeep2");
+  if (!daysToKeep2 || daysToKeep2->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, daysToKeep2 not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.daysToKeep2 = daysToKeep2->valueint;
+
+  cJSON *minRowsPerFileBlock = cJSON_GetObjectItem(root, "minRowsPerFileBlock");
+  if (!minRowsPerFileBlock || minRowsPerFileBlock->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, minRowsPerFileBlock not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.minRowsPerFileBlock = minRowsPerFileBlock->valueint;
+
+  cJSON *maxRowsPerFileBlock = cJSON_GetObjectItem(root, "maxRowsPerFileBlock");
+  if (!maxRowsPerFileBlock || maxRowsPerFileBlock->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, maxRowsPerFileBlock not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.maxRowsPerFileBlock = maxRowsPerFileBlock->valueint;
+
+  cJSON *precision = cJSON_GetObjectItem(root, "precision");
+  if (!precision || precision->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, precision not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.precision = (int8_t)precision->valueint;
+
+  cJSON *compression = cJSON_GetObjectItem(root, "compression");
+  if (!compression || compression->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, compression not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.compression = (int8_t)compression->valueint;
+
+  cJSON *walLevel = cJSON_GetObjectItem(root, "walLevel");
+  if (!walLevel || walLevel->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, walLevel not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.walLevel = (int8_t)walLevel->valueint;
+
+  cJSON *fsyncPeriod = cJSON_GetObjectItem(root, "fsync");
+  if (!walLevel || walLevel->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, fsyncPeriod not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.fsyncPeriod = fsyncPeriod->valueint;
+
+  cJSON *wals = cJSON_GetObjectItem(root, "wals");
+  if (!wals || wals->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, wals not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.wals = (int8_t)wals->valueint;
+
+  cJSON *replica = cJSON_GetObjectItem(root, "replica");
+  if (!replica || replica->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, replica not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.replications = (int8_t)replica->valueint;
+
+  cJSON *quorum = cJSON_GetObjectItem(root, "quorum");
+  if (!quorum || quorum->type != cJSON_Number) {
+    vError("vgId: %d, failed to read %s, quorum not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+  vnodeMsg.cfg.quorum = (int8_t)quorum->valueint;
+
+  cJSON *nodeInfos = cJSON_GetObjectItem(root, "nodeInfos");
+  if (!nodeInfos || nodeInfos->type != cJSON_Array) {
+    vError("vgId:%d, failed to read %s, nodeInfos not found", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+
+  int size = cJSON_GetArraySize(nodeInfos);
+  if (size != vnodeMsg.cfg.replications) {
+    vError("vgId:%d, failed to read %s, nodeInfos size not matched", pVnode->vgId, file);
+    goto PARSE_VCFG_ERROR;
+  }
+
+  for (int i = 0; i < size; ++i) {
+    cJSON *nodeInfo = cJSON_GetArrayItem(nodeInfos, i);
+    if (nodeInfo == NULL) continue;
+    SVnodeDesc *node = &vnodeMsg.nodes[i];
+
+    cJSON *nodeId = cJSON_GetObjectItem(nodeInfo, "nodeId");
+    if (!nodeId || nodeId->type != cJSON_Number) {
+      vError("vgId:%d, failed to read %s, nodeId not found", pVnode->vgId, file);
+      goto PARSE_VCFG_ERROR;
+    }
+    node->nodeId = nodeId->valueint;
+
+    cJSON *nodeEp = cJSON_GetObjectItem(nodeInfo, "nodeEp");
+    if (!nodeEp || nodeEp->type != cJSON_String || nodeEp->valuestring == NULL) {
+      vError("vgId:%d, failed to read %s, nodeFqdn not found", pVnode->vgId, file);
+      goto PARSE_VCFG_ERROR;
+    }
+    tstrncpy(node->nodeEp, nodeEp->valuestring, TSDB_EP_LEN);
+
+    if (!nodeChanged) {
+      nodeChanged = dnodeCheckEpChanged(node->nodeId, node->nodeEp);
+    }
+  }
+
+  ret = TSDB_CODE_SUCCESS;
+
+PARSE_VCFG_ERROR:
+  if (content != NULL) free(content);
+  if (root != NULL) cJSON_Delete(root);
+  if (fp != NULL) fclose(fp);
+
+  if (nodeChanged) {
+    vnodeWriteCfg(&vnodeMsg);
+  }
+
+  if (ret == TSDB_CODE_SUCCESS) {
+    vnodeLoadCfg(pVnode, &vnodeMsg);
+  }
+
+  terrno = 0;
+  return ret;
+}
+
+int32_t vnodeWriteCfg(SCreateVnodeMsg *pMsg) {
+  char file[TSDB_FILENAME_LEN + 30] = {0};
+  sprintf(file, "%s/vnode%d/config.json", tsVnodeDir, pMsg->cfg.vgId);
+
+  FILE *fp = fopen(file, "w");
+  if (!fp) {
+    vError("vgId:%d, failed to write %s error:%s", pMsg->cfg.vgId, file, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return terrno;
+  }
+
+  int32_t len = 0;
+  int32_t maxLen = 1000;
+  char *  content = calloc(1, maxLen + 1);
+
+  len += snprintf(content + len, maxLen - len, "{\n");
+  len += snprintf(content + len, maxLen - len, "  \"db\": \"%s\",\n", pMsg->db);
+  len += snprintf(content + len, maxLen - len, "  \"cfgVersion\": %d,\n", pMsg->cfg.cfgVersion);
+  len += snprintf(content + len, maxLen - len, "  \"cacheBlockSize\": %d,\n", pMsg->cfg.cacheBlockSize);
+  len += snprintf(content + len, maxLen - len, "  \"totalBlocks\": %d,\n", pMsg->cfg.totalBlocks);
+  len += snprintf(content + len, maxLen - len, "  \"daysPerFile\": %d,\n", pMsg->cfg.daysPerFile);
+  len += snprintf(content + len, maxLen - len, "  \"daysToKeep\": %d,\n", pMsg->cfg.daysToKeep);
+  len += snprintf(content + len, maxLen - len, "  \"daysToKeep1\": %d,\n", pMsg->cfg.daysToKeep1);
+  len += snprintf(content + len, maxLen - len, "  \"daysToKeep2\": %d,\n", pMsg->cfg.daysToKeep2);
+  len += snprintf(content + len, maxLen - len, "  \"minRowsPerFileBlock\": %d,\n", pMsg->cfg.minRowsPerFileBlock);
+  len += snprintf(content + len, maxLen - len, "  \"maxRowsPerFileBlock\": %d,\n", pMsg->cfg.maxRowsPerFileBlock);
+  len += snprintf(content + len, maxLen - len, "  \"precision\": %d,\n", pMsg->cfg.precision);
+  len += snprintf(content + len, maxLen - len, "  \"compression\": %d,\n", pMsg->cfg.compression);
+  len += snprintf(content + len, maxLen - len, "  \"walLevel\": %d,\n", pMsg->cfg.walLevel);
+  len += snprintf(content + len, maxLen - len, "  \"fsync\": %d,\n", pMsg->cfg.fsyncPeriod);
+  len += snprintf(content + len, maxLen - len, "  \"replica\": %d,\n", pMsg->cfg.replications);
+  len += snprintf(content + len, maxLen - len, "  \"wals\": %d,\n", pMsg->cfg.wals);
+  len += snprintf(content + len, maxLen - len, "  \"quorum\": %d,\n", pMsg->cfg.quorum);
+  len += snprintf(content + len, maxLen - len, "  \"nodeInfos\": [{\n");
+  for (int32_t i = 0; i < pMsg->cfg.replications; i++) {
+    SVnodeDesc *node = &pMsg->nodes[i];
+    dnodeUpdateEp(node->nodeId, node->nodeEp, NULL, NULL);
+    len += snprintf(content + len, maxLen - len, "    \"nodeId\": %d,\n", node->nodeId);
+    len += snprintf(content + len, maxLen - len, "    \"nodeEp\": \"%s\"\n", node->nodeEp);
+    if (i < pMsg->cfg.replications - 1) {
+      len += snprintf(content + len, maxLen - len, "  },{\n");
+    } else {
+      len += snprintf(content + len, maxLen - len, "  }]\n");
+    }
+  }
+  len += snprintf(content + len, maxLen - len, "}\n");
+
+  fwrite(content, 1, len, fp);
+  fflush(fp);
+  fclose(fp);
+  free(content);
+  terrno = 0;
+
+  vInfo("vgId:%d, successed to write %s", pMsg->cfg.vgId, file);
+  return TSDB_CODE_SUCCESS;
+}
diff --git a/src/vnode/src/vnodeMain.c b/src/vnode/src/vnodeMain.c
index 3b3f0420b5..753076372f 100644
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@@ -31,18 +31,14 @@
 #include "vnodeInt.h"
 #include "query.h"
 #include "dnode.h"
-
-#define TSDB_VNODE_VERSION_CONTENT_LEN 31
+#include "vnodeCfg.h"
+#include "vnodeVersion.h"
 
 static SHashObj*tsDnodeVnodesHash;
 static void     vnodeCleanUp(SVnodeObj *pVnode);
-static int32_t  vnodeSaveCfg(SMDCreateVnodeMsg *pVnodeCfg);
-static int32_t  vnodeReadCfg(SVnodeObj *pVnode);
-static int32_t  vnodeSaveVersion(SVnodeObj *pVnode);
-static int32_t  vnodeReadVersion(SVnodeObj *pVnode);
 static int      vnodeProcessTsdbStatus(void *arg, int status);
 static uint32_t vnodeGetFileInfo(void *ahandle, char *name, uint32_t *index, uint32_t eindex, int64_t *size, uint64_t *fversion);
-static int      vnodeGetWalInfo(void *ahandle, char *name, uint32_t *index);
+static int      vnodeGetWalInfo(void *ahandle, char *fileName, int64_t *fileId);
 static void     vnodeNotifyRole(void *ahandle, int8_t role);
 static void     vnodeCtrlFlow(void *handle, int32_t mseconds); 
 static int      vnodeNotifyFileSynced(void *ahandle, uint64_t fversion);
@@ -90,7 +86,7 @@ void vnodeCleanupResources() {
   syncCleanUp();
 }
 
-int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
+int32_t vnodeCreate(SCreateVnodeMsg *pVnodeCfg) {
   int32_t code;
 
   SVnodeObj *pVnode = vnodeAcquire(pVnodeCfg->cfg.vgId);
@@ -128,7 +124,7 @@ int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
     }
   }
 
-  code = vnodeSaveCfg(pVnodeCfg);
+  code = vnodeWriteCfg(pVnodeCfg);
   if (code != TSDB_CODE_SUCCESS) {
     vError("vgId:%d, failed to save vnode cfg, reason:%s", pVnodeCfg->cfg.vgId, tstrerror(code));
     return code;
@@ -138,7 +134,6 @@ int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
   tsdbCfg.tsdbId              = pVnodeCfg->cfg.vgId;
   tsdbCfg.cacheBlockSize      = pVnodeCfg->cfg.cacheBlockSize;
   tsdbCfg.totalBlocks         = pVnodeCfg->cfg.totalBlocks;
-  // tsdbCfg.maxTables           = pVnodeCfg->cfg.maxTables;
   tsdbCfg.daysPerFile         = pVnodeCfg->cfg.daysPerFile;
   tsdbCfg.keep                = pVnodeCfg->cfg.daysToKeep;
   tsdbCfg.minRowsPerFileBlock = pVnodeCfg->cfg.minRowsPerFileBlock;
@@ -177,7 +172,7 @@ int32_t vnodeDrop(int32_t vgId) {
   return TSDB_CODE_SUCCESS;
 }
 
-int32_t vnodeAlter(void *param, SMDCreateVnodeMsg *pVnodeCfg) {
+int32_t vnodeAlter(void *param, SCreateVnodeMsg *pVnodeCfg) {
   SVnodeObj *pVnode = param;
 
   // vnode in non-ready state and still needs to return success instead of TSDB_CODE_VND_INVALID_STATUS
@@ -187,7 +182,7 @@ int32_t vnodeAlter(void *param, SMDCreateVnodeMsg *pVnodeCfg) {
     return TSDB_CODE_SUCCESS;
   }
 
-  int32_t code = vnodeSaveCfg(pVnodeCfg);
+  int32_t code = vnodeWriteCfg(pVnodeCfg);
   if (code != TSDB_CODE_SUCCESS) {
     pVnode->status = TAOS_VN_STATUS_READY;
     return code; 
@@ -304,6 +299,7 @@ int32_t vnodeOpen(int32_t vnode, char *rootDir) {
   }
 
   sprintf(temp, "%s/wal", rootDir);
+  pVnode->walCfg.vgId = pVnode->vgId;
   pVnode->wal = walOpen(temp, &pVnode->walCfg);
   if (pVnode->wal == NULL) { 
     vnodeCleanUp(pVnode);
@@ -315,6 +311,8 @@ int32_t vnodeOpen(int32_t vnode, char *rootDir) {
     pVnode->version = walGetVersion(pVnode->wal);
   }
 
+  walRenew(pVnode->wal);
+
   SSyncInfo syncInfo;
   syncInfo.vgId = pVnode->vgId;
   syncInfo.version = pVnode->version;
@@ -500,7 +498,7 @@ void *vnodeGetWal(void *pVnode) {
   return ((SVnodeObj *)pVnode)->wal;
 }
 
-static void vnodeBuildVloadMsg(SVnodeObj *pVnode, SDMStatusMsg *pStatus) {
+static void vnodeBuildVloadMsg(SVnodeObj *pVnode, SStatusMsg *pStatus) {
   int64_t totalStorage = 0;
   int64_t compStorage = 0;
   int64_t pointsWritten = 0;
@@ -544,7 +542,7 @@ int32_t vnodeGetVnodeList(int32_t vnodeList[], int32_t *numOfVnodes) {
 }
 
 void vnodeBuildStatusMsg(void *param) {
-  SDMStatusMsg *pStatus = param;
+  SStatusMsg *pStatus = param;
   SHashMutableIterator *pIter = taosHashCreateIter(tsDnodeVnodesHash);
 
   while (taosHashIterNext(pIter)) {
@@ -558,7 +556,7 @@ void vnodeBuildStatusMsg(void *param) {
   taosHashDestroyIter(pIter);
 }
 
-void vnodeSetAccess(SDMVgroupAccess *pAccess, int32_t numOfVnodes) {
+void vnodeSetAccess(SVgroupAccess *pAccess, int32_t numOfVnodes) {
   for (int32_t i = 0; i < numOfVnodes; ++i) {
     pAccess[i].vgId = htonl(pAccess[i].vgId);
     SVnodeObj *pVnode = vnodeAcquire(pAccess[i].vgId);
@@ -606,25 +604,27 @@ static int vnodeProcessTsdbStatus(void *arg, int status) {
   SVnodeObj *pVnode = arg;
 
   if (status == TSDB_STATUS_COMMIT_START) {
-    pVnode->fversion = pVnode->version; 
+    pVnode->fversion = pVnode->version;
     return walRenew(pVnode->wal);
   }
 
-  if (status == TSDB_STATUS_COMMIT_OVER)
+  if (status == TSDB_STATUS_COMMIT_OVER) {
     return vnodeSaveVersion(pVnode);
+  }
 
-  return 0; 
+  return 0;
 }
 
-static uint32_t vnodeGetFileInfo(void *ahandle, char *name, uint32_t *index, uint32_t eindex, int64_t *size, uint64_t *fversion) {
+static uint32_t vnodeGetFileInfo(void *ahandle, char *name, uint32_t *index, uint32_t eindex, int64_t *size,
+                                 uint64_t *fversion) {
   SVnodeObj *pVnode = ahandle;
   *fversion = pVnode->fversion;
   return tsdbGetFileInfo(pVnode->tsdb, name, index, eindex, size);
 }
 
-static int vnodeGetWalInfo(void *ahandle, char *name, uint32_t *index) {
+static int vnodeGetWalInfo(void *ahandle, char *fileName, int64_t *fileId) {
   SVnodeObj *pVnode = ahandle;
-  return walGetWalFile(pVnode->wal, name, index);
+  return walGetWalFile(pVnode->wal, fileName, fileId);
 }
 
 static void vnodeNotifyRole(void *ahandle, int8_t role) {
@@ -641,17 +641,18 @@ static void vnodeNotifyRole(void *ahandle, int8_t role) {
 
 static void vnodeCtrlFlow(void *ahandle, int32_t mseconds) {
   SVnodeObj *pVnode = ahandle;
-  if (pVnode->delay != mseconds) 
+  if (pVnode->delay != mseconds) {
     vInfo("vgId:%d, sync flow control, mseconds:%d", pVnode->vgId, mseconds);
+  }
   pVnode->delay = mseconds;
 }
 
-static int vnodeResetTsdb(SVnodeObj *pVnode)
-{
+static int vnodeResetTsdb(SVnodeObj *pVnode) {
   char rootDir[128] = "\0";
   sprintf(rootDir, "%s/tsdb", pVnode->rootDir);
 
-  if (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_RESET) != TAOS_VN_STATUS_READY) {
+  if (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_RESET) !=
+      TAOS_VN_STATUS_READY) {
     return -1;
   }
 
@@ -676,7 +677,7 @@ static int vnodeResetTsdb(SVnodeObj *pVnode)
   pVnode->tsdb = tsdbOpenRepo(rootDir, &appH);
 
   pVnode->status = TAOS_VN_STATUS_READY;
-  vnodeRelease(pVnode);  
+  vnodeRelease(pVnode);
 
   return 0;
 }
@@ -691,360 +692,3 @@ static int vnodeNotifyFileSynced(void *ahandle, uint64_t fversion) {
 
   return vnodeResetTsdb(pVnode);
 }
-
-static int32_t vnodeSaveCfg(SMDCreateVnodeMsg *pVnodeCfg) {
-  char cfgFile[TSDB_FILENAME_LEN + 30] = {0};
-  sprintf(cfgFile, "%s/vnode%d/config.json", tsVnodeDir, pVnodeCfg->cfg.vgId);
-  FILE *fp = fopen(cfgFile, "w");
-  if (!fp) {
-    vError("vgId:%d, failed to open vnode cfg file for write, file:%s error:%s", pVnodeCfg->cfg.vgId, cfgFile,
-           strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return terrno;
-  }
-
-  int32_t len = 0;
-  int32_t maxLen = 1000;
-  char *  content = calloc(1, maxLen + 1);
-  if (content == NULL) {
-    fclose(fp);
-    return TSDB_CODE_VND_OUT_OF_MEMORY;
-  }
-
-  len += snprintf(content + len, maxLen - len, "{\n");
-  len += snprintf(content + len, maxLen - len, "  \"db\": \"%s\",\n", pVnodeCfg->db);
-  len += snprintf(content + len, maxLen - len, "  \"cfgVersion\": %d,\n", pVnodeCfg->cfg.cfgVersion);
-  len += snprintf(content + len, maxLen - len, "  \"cacheBlockSize\": %d,\n", pVnodeCfg->cfg.cacheBlockSize);
-  len += snprintf(content + len, maxLen - len, "  \"totalBlocks\": %d,\n", pVnodeCfg->cfg.totalBlocks);
-  // len += snprintf(content + len, maxLen - len, "  \"maxTables\": %d,\n", pVnodeCfg->cfg.maxTables);
-  len += snprintf(content + len, maxLen - len, "  \"daysPerFile\": %d,\n", pVnodeCfg->cfg.daysPerFile);
-  len += snprintf(content + len, maxLen - len, "  \"daysToKeep\": %d,\n", pVnodeCfg->cfg.daysToKeep);
-  len += snprintf(content + len, maxLen - len, "  \"daysToKeep1\": %d,\n", pVnodeCfg->cfg.daysToKeep1);
-  len += snprintf(content + len, maxLen - len, "  \"daysToKeep2\": %d,\n", pVnodeCfg->cfg.daysToKeep2);
-  len += snprintf(content + len, maxLen - len, "  \"minRowsPerFileBlock\": %d,\n", pVnodeCfg->cfg.minRowsPerFileBlock);
-  len += snprintf(content + len, maxLen - len, "  \"maxRowsPerFileBlock\": %d,\n", pVnodeCfg->cfg.maxRowsPerFileBlock);
-  // len += snprintf(content + len, maxLen - len, "  \"commitTime\": %d,\n", pVnodeCfg->cfg.commitTime);
-  len += snprintf(content + len, maxLen - len, "  \"precision\": %d,\n", pVnodeCfg->cfg.precision);
-  len += snprintf(content + len, maxLen - len, "  \"compression\": %d,\n", pVnodeCfg->cfg.compression);
-  len += snprintf(content + len, maxLen - len, "  \"walLevel\": %d,\n", pVnodeCfg->cfg.walLevel);
-  len += snprintf(content + len, maxLen - len, "  \"fsync\": %d,\n", pVnodeCfg->cfg.fsyncPeriod);
-  len += snprintf(content + len, maxLen - len, "  \"replica\": %d,\n", pVnodeCfg->cfg.replications);
-  len += snprintf(content + len, maxLen - len, "  \"wals\": %d,\n", pVnodeCfg->cfg.wals);
-  len += snprintf(content + len, maxLen - len, "  \"quorum\": %d,\n", pVnodeCfg->cfg.quorum);
-
-  len += snprintf(content + len, maxLen - len, "  \"nodeInfos\": [{\n");
-
-  vInfo("vgId:%d, save vnode cfg, replica:%d", pVnodeCfg->cfg.vgId, pVnodeCfg->cfg.replications);
-  for (int32_t i = 0; i < pVnodeCfg->cfg.replications; i++) {
-    len += snprintf(content + len, maxLen - len, "    \"nodeId\": %d,\n", pVnodeCfg->nodes[i].nodeId);
-    len += snprintf(content + len, maxLen - len, "    \"nodeEp\": \"%s\"\n", pVnodeCfg->nodes[i].nodeEp);
-    vInfo("vgId:%d, save vnode cfg, nodeId:%d nodeEp:%s", pVnodeCfg->cfg.vgId, pVnodeCfg->nodes[i].nodeId,
-          pVnodeCfg->nodes[i].nodeEp);
-
-    if (i < pVnodeCfg->cfg.replications - 1) {
-      len += snprintf(content + len, maxLen - len, "  },{\n");
-    } else {
-      len += snprintf(content + len, maxLen - len, "  }]\n");
-    }
-  }
-  len += snprintf(content + len, maxLen - len, "}\n");
-
-  fwrite(content, 1, len, fp);
-  fflush(fp);
-  fclose(fp);
-  free(content);
-
-  vInfo("vgId:%d, save vnode cfg successed", pVnodeCfg->cfg.vgId);
-
-  return TSDB_CODE_SUCCESS;
-}
-
-static int32_t vnodeReadCfg(SVnodeObj *pVnode) {
-  cJSON  *root = NULL;
-  char   *content = NULL;
-  char    cfgFile[TSDB_FILENAME_LEN + 30] = {0};
-  int     maxLen = 1000;
-
-  terrno = TSDB_CODE_VND_APP_ERROR;
-  sprintf(cfgFile, "%s/vnode%d/config.json", tsVnodeDir, pVnode->vgId);
-  FILE *fp = fopen(cfgFile, "r");
-  if (!fp) {
-    vError("vgId:%d, failed to open vnode cfg file:%s to read, error:%s", pVnode->vgId,
-           cfgFile, strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    goto PARSE_OVER;
-  }
-
-  content = calloc(1, maxLen + 1);
-  if (content == NULL) goto PARSE_OVER;
-  int len = fread(content, 1, maxLen, fp);
-  if (len <= 0) {
-    vError("vgId:%d, failed to read vnode cfg, content is null", pVnode->vgId);
-    free(content);
-    fclose(fp);
-    return errno;
-  }
-
-  root = cJSON_Parse(content);
-  if (root == NULL) {
-    vError("vgId:%d, failed to read vnode cfg, invalid json format", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-
-  cJSON *db = cJSON_GetObjectItem(root, "db");
-  if (!db || db->type != cJSON_String || db->valuestring == NULL) {
-    vError("vgId:%d, failed to read vnode cfg, db not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  strcpy(pVnode->db, db->valuestring);
-  
-  cJSON *cfgVersion = cJSON_GetObjectItem(root, "cfgVersion");
-  if (!cfgVersion || cfgVersion->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, cfgVersion not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->cfgVersion = cfgVersion->valueint;
-
-  cJSON *cacheBlockSize = cJSON_GetObjectItem(root, "cacheBlockSize");
-  if (!cacheBlockSize || cacheBlockSize->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, cacheBlockSize not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.cacheBlockSize = cacheBlockSize->valueint;
-
-  cJSON *totalBlocks = cJSON_GetObjectItem(root, "totalBlocks");
-  if (!totalBlocks || totalBlocks->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, totalBlocks not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.totalBlocks = totalBlocks->valueint;
-
-  // cJSON *maxTables = cJSON_GetObjectItem(root, "maxTables");
-  // if (!maxTables || maxTables->type != cJSON_Number) {
-  //   vError("vgId:%d, failed to read vnode cfg, maxTables not found", pVnode->vgId);
-  //   goto PARSE_OVER;
-  // }
-  // pVnode->tsdbCfg.maxTables = maxTables->valueint;
-
-  cJSON *daysPerFile = cJSON_GetObjectItem(root, "daysPerFile");
-  if (!daysPerFile || daysPerFile->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, daysPerFile not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.daysPerFile = daysPerFile->valueint;
-
-  cJSON *daysToKeep = cJSON_GetObjectItem(root, "daysToKeep");
-  if (!daysToKeep || daysToKeep->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, daysToKeep not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.keep = daysToKeep->valueint;
-
-  cJSON *daysToKeep1 = cJSON_GetObjectItem(root, "daysToKeep1");
-  if (!daysToKeep1 || daysToKeep1->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, daysToKeep1 not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.keep1 = daysToKeep1->valueint;
-
-  cJSON *daysToKeep2 = cJSON_GetObjectItem(root, "daysToKeep2");
-  if (!daysToKeep2 || daysToKeep2->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, daysToKeep2 not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.keep2 = daysToKeep2->valueint;
-
-  cJSON *minRowsPerFileBlock = cJSON_GetObjectItem(root, "minRowsPerFileBlock");
-  if (!minRowsPerFileBlock || minRowsPerFileBlock->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, minRowsPerFileBlock not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.minRowsPerFileBlock = minRowsPerFileBlock->valueint;
-
-  cJSON *maxRowsPerFileBlock = cJSON_GetObjectItem(root, "maxRowsPerFileBlock");
-  if (!maxRowsPerFileBlock || maxRowsPerFileBlock->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, maxRowsPerFileBlock not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.maxRowsPerFileBlock = maxRowsPerFileBlock->valueint;
-
-  // cJSON *commitTime = cJSON_GetObjectItem(root, "commitTime");
-  // if (!commitTime || commitTime->type != cJSON_Number) {
-  //   vError("vgId:%d, failed to read vnode cfg, commitTime not found", pVnode->vgId);
-  //   goto PARSE_OVER;
-  // }
-  // pVnode->tsdbCfg.commitTime = (int8_t)commitTime->valueint;
-
-  cJSON *precision = cJSON_GetObjectItem(root, "precision");
-  if (!precision || precision->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, precision not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.precision = (int8_t)precision->valueint;
-
-  cJSON *compression = cJSON_GetObjectItem(root, "compression");
-  if (!compression || compression->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, compression not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->tsdbCfg.compression = (int8_t)compression->valueint;
-
-  cJSON *walLevel = cJSON_GetObjectItem(root, "walLevel");
-  if (!walLevel || walLevel->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, walLevel not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->walCfg.walLevel = (int8_t) walLevel->valueint;
-
-  cJSON *fsyncPeriod = cJSON_GetObjectItem(root, "fsync");
-  if (!walLevel || walLevel->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, fsyncPeriod not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->walCfg.fsyncPeriod = fsyncPeriod->valueint;
-
-  cJSON *wals = cJSON_GetObjectItem(root, "wals");
-  if (!wals || wals->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, wals not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->walCfg.wals = (int8_t)wals->valueint;
-  pVnode->walCfg.keep = 0;
-
-  cJSON *replica = cJSON_GetObjectItem(root, "replica");
-  if (!replica || replica->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode cfg, replica not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->syncCfg.replica = (int8_t)replica->valueint;
-
-  cJSON *quorum = cJSON_GetObjectItem(root, "quorum");
-  if (!quorum || quorum->type != cJSON_Number) {
-    vError("vgId: %d, failed to read vnode cfg, quorum not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->syncCfg.quorum = (int8_t)quorum->valueint;
-
-  cJSON *nodeInfos = cJSON_GetObjectItem(root, "nodeInfos");
-  if (!nodeInfos || nodeInfos->type != cJSON_Array) {
-    vError("vgId:%d, failed to read vnode cfg, nodeInfos not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-
-  int size = cJSON_GetArraySize(nodeInfos);
-  if (size != pVnode->syncCfg.replica) {
-    vError("vgId:%d, failed to read vnode cfg, nodeInfos size not matched", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-
-  for (int i = 0; i < size; ++i) {
-    cJSON *nodeInfo = cJSON_GetArrayItem(nodeInfos, i);
-    if (nodeInfo == NULL) continue;
-
-    cJSON *nodeId = cJSON_GetObjectItem(nodeInfo, "nodeId");
-    if (!nodeId || nodeId->type != cJSON_Number) {
-      vError("vgId:%d, failed to read vnode cfg, nodeId not found", pVnode->vgId);
-      goto PARSE_OVER;
-    }
-    pVnode->syncCfg.nodeInfo[i].nodeId = nodeId->valueint;
-
-    cJSON *nodeEp = cJSON_GetObjectItem(nodeInfo, "nodeEp");
-    if (!nodeEp || nodeEp->type != cJSON_String || nodeEp->valuestring == NULL) {
-      vError("vgId:%d, failed to read vnode cfg, nodeFqdn not found", pVnode->vgId);
-      goto PARSE_OVER;
-    }
-
-    taosGetFqdnPortFromEp(nodeEp->valuestring, pVnode->syncCfg.nodeInfo[i].nodeFqdn, &pVnode->syncCfg.nodeInfo[i].nodePort);
-    pVnode->syncCfg.nodeInfo[i].nodePort += TSDB_PORT_SYNC;
-  }
-
-  terrno = TSDB_CODE_SUCCESS;
-
-  vInfo("vgId:%d, read vnode cfg successfully, replcia:%d", pVnode->vgId, pVnode->syncCfg.replica);
-  for (int32_t i = 0; i < pVnode->syncCfg.replica; i++) {
-    vInfo("vgId:%d, dnode:%d, %s:%d", pVnode->vgId, pVnode->syncCfg.nodeInfo[i].nodeId,
-           pVnode->syncCfg.nodeInfo[i].nodeFqdn, pVnode->syncCfg.nodeInfo[i].nodePort);
-  }
-
-PARSE_OVER:
-  taosTFree(content);
-  cJSON_Delete(root);
-  if (fp) fclose(fp);
-  return terrno;
-}
-
-static int32_t vnodeSaveVersion(SVnodeObj *pVnode) {
-  char versionFile[TSDB_FILENAME_LEN + 30] = {0};
-  sprintf(versionFile, "%s/vnode%d/version.json", tsVnodeDir, pVnode->vgId);
-  FILE *fp = fopen(versionFile, "w");
-  if (!fp) {
-    vError("vgId:%d, failed to open vnode version file for write, file:%s error:%s", pVnode->vgId,
-           versionFile, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno); 
-  }
-
-  int32_t len = 0;
-  int32_t maxLen = 30;
-  char content[TSDB_VNODE_VERSION_CONTENT_LEN] = {0};
-
-  len += snprintf(content + len, maxLen - len, "{\n");
-  len += snprintf(content + len, maxLen - len, "  \"version\": %" PRId64 "\n", pVnode->fversion);
-  len += snprintf(content + len, maxLen - len, "}\n");
-
-  fwrite(content, 1, len, fp);
-  fflush(fp);
-  fclose(fp);
-
-  vInfo("vgId:%d, save vnode version:%" PRId64 " succeed", pVnode->vgId, pVnode->fversion);
-
-  return TSDB_CODE_SUCCESS;
-}
-
-static int32_t vnodeReadVersion(SVnodeObj *pVnode) {
-  char    versionFile[TSDB_FILENAME_LEN + 30] = {0};
-  char   *content = NULL;
-  cJSON  *root = NULL;
-  int     maxLen = 100;
-
-  terrno = TSDB_CODE_VND_INVALID_VRESION_FILE;
-  sprintf(versionFile, "%s/vnode%d/version.json", tsVnodeDir, pVnode->vgId);
-  FILE *fp = fopen(versionFile, "r");
-  if (!fp) {
-    if (errno != ENOENT) {
-      vError("vgId:%d, failed to open version file:%s error:%s", pVnode->vgId, versionFile, strerror(errno));
-      terrno = TAOS_SYSTEM_ERROR(errno);
-    } else {
-      terrno = TSDB_CODE_SUCCESS;
-    }
-    goto PARSE_OVER;
-  }
-
-  content = calloc(1, maxLen + 1);
-  int len = fread(content, 1, maxLen, fp);
-  if (len <= 0) {
-    vError("vgId:%d, failed to read vnode version, content is null", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-
-  root = cJSON_Parse(content);
-  if (root == NULL) {
-    vError("vgId:%d, failed to read vnode version, invalid json format", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-
-  cJSON *ver = cJSON_GetObjectItem(root, "version");
-  if (!ver || ver->type != cJSON_Number) {
-    vError("vgId:%d, failed to read vnode version, version not found", pVnode->vgId);
-    goto PARSE_OVER;
-  }
-  pVnode->version = ver->valueint;
-
-  terrno = TSDB_CODE_SUCCESS;
-  vInfo("vgId:%d, read vnode version successfully, version:%" PRId64, pVnode->vgId, pVnode->version);
-
-PARSE_OVER:
-  taosTFree(content);
-  cJSON_Delete(root);
-  if (fp) fclose(fp);
-  return terrno;
-}
diff --git a/src/vnode/src/vnodeVersion.c b/src/vnode/src/vnodeVersion.c
new file mode 100644
index 0000000000..1d0695fb53
--- /dev/null
+++ b/src/vnode/src/vnodeVersion.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "taoserror.h"
+#include "cJSON.h"
+#include "tglobal.h"
+#include "tsdb.h"
+#include "vnodeInt.h"
+#include "vnodeVersion.h"
+
+int32_t vnodeReadVersion(SVnodeObj *pVnode) {
+  int32_t len = 0;
+  int32_t maxLen = 100;
+  char *  content = calloc(1, maxLen + 1);
+  cJSON * root = NULL;
+  FILE *  fp = NULL;
+
+  terrno = TSDB_CODE_VND_INVALID_VRESION_FILE;
+  char file[TSDB_FILENAME_LEN + 30] = {0};
+  sprintf(file, "%s/vnode%d/version.json", tsVnodeDir, pVnode->vgId);
+
+  fp = fopen(file, "r");
+  if (!fp) {
+    if (errno != ENOENT) {
+      vError("vgId:%d, failed to read %s, error:%s", pVnode->vgId, file, strerror(errno));
+      terrno = TAOS_SYSTEM_ERROR(errno);
+    } else {
+      terrno = TSDB_CODE_SUCCESS;
+    }
+    goto PARSE_VER_ERROR;
+  }
+
+  len = fread(content, 1, maxLen, fp);
+  if (len <= 0) {
+    vError("vgId:%d, failed to read %s, content is null", pVnode->vgId, file);
+    goto PARSE_VER_ERROR;
+  }
+
+  root = cJSON_Parse(content);
+  if (root == NULL) {
+    vError("vgId:%d, failed to read %s, invalid json format", pVnode->vgId, file);
+    goto PARSE_VER_ERROR;
+  }
+
+  cJSON *ver = cJSON_GetObjectItem(root, "version");
+  if (!ver || ver->type != cJSON_Number) {
+    vError("vgId:%d, failed to read %s, version not found", pVnode->vgId, file);
+    goto PARSE_VER_ERROR;
+  }
+  pVnode->version = ver->valueint;
+
+  terrno = TSDB_CODE_SUCCESS;
+  vInfo("vgId:%d, read %s successfully, version:%" PRId64, pVnode->vgId, file, pVnode->version);
+
+PARSE_VER_ERROR:
+  if (content != NULL) free(content);
+  if (root != NULL) cJSON_Delete(root);
+  if (fp != NULL) fclose(fp);
+
+  return terrno;
+}
+
+int32_t vnodeSaveVersion(SVnodeObj *pVnode) {
+  char file[TSDB_FILENAME_LEN + 30] = {0};
+  sprintf(file, "%s/vnode%d/version.json", tsVnodeDir, pVnode->vgId);
+
+  FILE *fp = fopen(file, "w");
+  if (!fp) {
+    vError("vgId:%d, failed to write %s, reason:%s", pVnode->vgId, file, strerror(errno));
+    return -1;
+  }
+
+  int32_t len = 0;
+  int32_t maxLen = 100;
+  char *  content = calloc(1, maxLen + 1);
+
+  len += snprintf(content + len, maxLen - len, "{\n");
+  len += snprintf(content + len, maxLen - len, "  \"version\": %" PRId64 "\n", pVnode->fversion);
+  len += snprintf(content + len, maxLen - len, "}\n");
+
+  fwrite(content, 1, len, fp);
+  fflush(fp);
+  fclose(fp);
+  free(content);
+  terrno = 0;
+
+  vInfo("vgId:%d, successed to write %s, version:%" PRId64, pVnode->vgId, file, pVnode->fversion);
+  return TSDB_CODE_SUCCESS;
+}
\ No newline at end of file
diff --git a/src/vnode/src/vnodeWrite.c b/src/vnode/src/vnodeWrite.c
index 855df81a1b..c2771c73c6 100644
--- a/src/vnode/src/vnodeWrite.c
+++ b/src/vnode/src/vnodeWrite.c
@@ -183,7 +183,7 @@ static int32_t vnodeProcessAlterTableMsg(SVnodeObj *pVnode, void *pCont, SRspRet
 }
 
 static int32_t vnodeProcessDropStableMsg(SVnodeObj *pVnode, void *pCont, SRspRet *pRet) {
-  SMDDropSTableMsg *pTable = pCont;
+  SDropSTableMsg *pTable = pCont;
   int32_t           code = TSDB_CODE_SUCCESS;
 
   vDebug("vgId:%d, stable:%s, start to drop", pVnode->vgId, pTable->tableId);
@@ -204,7 +204,6 @@ static int32_t vnodeProcessUpdateTagValMsg(SVnodeObj *pVnode, void *pCont, SRspR
   return TSDB_CODE_SUCCESS;
 }
 
-
 int vnodeWriteCqMsgToQueue(void *param, void *data, int type) {
   SVnodeObj *pVnode = param;
   SWalHead * pHead = data;
@@ -222,7 +221,6 @@ int vnodeWriteCqMsgToQueue(void *param, void *data, int type) {
   return 0;
 }
 
-
 int vnodeWriteToQueue(void *param, void *data, int type) {
   SVnodeObj *pVnode = param;
   SWalHead * pHead = data;
diff --git a/src/wal/inc/walInt.h b/src/wal/inc/walInt.h
index 593611589d..7e731d44db 100644
--- a/src/wal/inc/walInt.h
+++ b/src/wal/inc/walInt.h
@@ -31,8 +31,32 @@ extern int32_t wDebugFlag;
 #define wDebug(...) { if (wDebugFlag & DEBUG_DEBUG) { taosPrintLog("WAL ", wDebugFlag, __VA_ARGS__); }}
 #define wTrace(...) { if (wDebugFlag & DEBUG_TRACE) { taosPrintLog("WAL ", wDebugFlag, __VA_ARGS__); }}
 
-#define walPrefix "wal"
-#define walSignature (uint32_t)(0xFAFBFDFE)
+#define WAL_PREFIX     "wal"
+#define WAL_PREFIX_LEN 3
+#define WAL_REFRESH_MS 1000
+#define WAL_MAX_SIZE   (1024 * 1024)
+#define WAL_SIGNATURE  ((uint32_t)(0xFAFBFDFE))
+#define WAL_PATH_LEN   (TSDB_FILENAME_LEN + 12)
+#define WAL_FILE_LEN   (TSDB_FILENAME_LEN + 32)
+#define WAL_FILE_NUM   3
+
+typedef struct {
+  uint64_t version;
+  int64_t  fileId;
+  int32_t  vgId;
+  int32_t  fd;
+  int32_t  keep;
+  int32_t  level;
+  int32_t  fsyncPeriod;
+  int32_t  fsyncSeq;
+  char     path[WAL_PATH_LEN];
+  char     name[WAL_FILE_LEN];
+  pthread_mutex_t mutex;
+} SWal;
+
+int32_t walGetNextFile(SWal *pWal, int64_t *nextFileId);
+int32_t walGetOldFile(SWal *pWal, int64_t curFileId, int32_t minDiff, int64_t *oldFileId);
+int32_t walGetNewFile(SWal *pWal, int64_t *newFileId);
 
 #ifdef __cplusplus
 }
diff --git a/src/wal/src/walMgmt.c b/src/wal/src/walMgmt.c
index 2dd094d860..272f44b93a 100644
--- a/src/wal/src/walMgmt.c
+++ b/src/wal/src/walMgmt.c
@@ -16,6 +16,212 @@
 #define _DEFAULT_SOURCE
 #include "os.h"
 #include "taoserror.h"
+#include "talloc.h"
+#include "tref.h"
 #include "twal.h"
 #include "walInt.h"
-#include "walMgmt.h"
\ No newline at end of file
+
+typedef struct {
+  int32_t   refId;
+  int32_t   seq;
+  int8_t    stop;
+  pthread_t thread;
+  pthread_mutex_t mutex;
+} SWalMgmt;
+
+static SWalMgmt tsWal;
+static int32_t  walCreateThread();
+static void     walStopThread();
+static int32_t  walInitObj(SWal *pWal);
+static void     walFreeObj(void *pWal);
+
+int32_t walInit() {
+  tmemzero(&tsWal, sizeof(SWalMgmt));
+  tsWal.refId = taosOpenRef(TSDB_MIN_VNODES, walFreeObj);
+
+  int32_t code = walCreateThread();
+  if (code != TSDB_CODE_SUCCESS) {
+    wError("failed to init wal module since %s", tstrerror(code));
+    return code;
+  }
+
+  wInfo("wal module is initialized, refId:%d", tsWal.refId);
+  return code;
+}
+
+void walCleanUp() {
+  walStopThread();
+  taosCloseRef(tsWal.refId);
+  wInfo("wal module is cleaned up");
+}
+
+void *walOpen(char *path, SWalCfg *pCfg) {
+  SWal *pWal = tcalloc(sizeof(SWal));
+  if (pWal == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return NULL;
+  }
+
+  pWal->vgId = pCfg->vgId;
+  pWal->fd = -1;
+  pWal->fileId = -1;
+  pWal->level = pCfg->walLevel;
+  pWal->keep = pCfg->keep;
+  pWal->fsyncPeriod = pCfg->fsyncPeriod;
+  tstrncpy(pWal->path, path, sizeof(pWal->path));
+  pthread_mutex_init(&pWal->mutex, NULL);
+
+  pWal->fsyncSeq = pCfg->fsyncPeriod % 1000;
+  if (pWal->fsyncSeq <= 0) pWal->fsyncSeq = 1;
+
+  if (walInitObj(pWal) != TSDB_CODE_SUCCESS) {
+    walFreeObj(pWal);
+    return NULL;
+  }
+
+  if (taosAddRef(tsWal.refId, pWal) != TSDB_CODE_SUCCESS) {
+    walFreeObj(pWal);
+    return NULL;
+  }
+
+  wDebug("vgId:%d, wal:%p is opened, level:%d fsyncPeriod:%d", pWal->vgId, pWal, pWal->level, pWal->fsyncPeriod);
+
+  return pWal;
+}
+
+int32_t walAlter(void *handle, SWalCfg *pCfg) {
+  if (handle == NULL) return TSDB_CODE_WAL_APP_ERROR;
+  SWal *pWal = handle;
+
+  if (pWal->level == pCfg->walLevel && pWal->fsyncPeriod == pCfg->fsyncPeriod) {
+    wDebug("vgId:%d, old walLevel:%d fsync:%d, new walLevel:%d fsync:%d not change", pWal->vgId, pWal->level,
+           pWal->fsyncPeriod, pCfg->walLevel, pCfg->fsyncPeriod);
+    return TSDB_CODE_SUCCESS;
+  }
+
+  wInfo("vgId:%d, change old walLevel:%d fsync:%d, new walLevel:%d fsync:%d", pWal->vgId, pWal->level,
+        pWal->fsyncPeriod, pCfg->walLevel, pCfg->fsyncPeriod);
+
+  pWal->level = pCfg->walLevel;
+  pWal->fsyncPeriod = pCfg->fsyncPeriod;
+  pWal->fsyncSeq = pCfg->fsyncPeriod % 1000;
+  if (pWal->fsyncSeq <= 0) pWal->fsyncSeq = 1;
+
+  return TSDB_CODE_SUCCESS;
+}
+
+void walClose(void *handle) {
+  if (handle == NULL) return;
+
+  SWal *pWal = handle;
+  pthread_mutex_lock(&pWal->mutex);
+
+  taosClose(pWal->fd);
+
+  if (!pWal->keep) {
+    int64_t fileId = -1;
+    while (walGetNextFile(pWal, &fileId) >= 0) {
+      snprintf(pWal->name, sizeof(pWal->name), "%s/%s%" PRId64, pWal->path, WAL_PREFIX, fileId);
+
+      if (fileId == pWal->fileId) {
+        wDebug("vgId:%d, wal:%p file:%s, it is closed and kept", pWal->vgId, pWal, pWal->name);
+      } else if (remove(pWal->name) < 0) {
+        wError("vgId:%d, wal:%p file:%s, failed to remove", pWal->vgId, pWal, pWal->name);
+      } else {
+        wDebug("vgId:%d, wal:%p file:%s, it is removed", pWal->vgId, pWal, pWal->name);
+      }
+    }
+  } else {
+    wDebug("vgId:%d, wal:%p file:%s, it is closed and kept", pWal->vgId, pWal, pWal->name);
+  }
+
+  pthread_mutex_unlock(&pWal->mutex);
+  taosRemoveRef(tsWal.refId, pWal);
+}
+
+static int32_t walInitObj(SWal *pWal) {
+  if (taosMkDir(pWal->path, 0755) != 0) {
+    wError("vgId:%d, path:%s, failed to create directory since %s", pWal->vgId, pWal->path, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  wDebug("vgId:%d, object is initialized", pWal->vgId);
+  return TSDB_CODE_SUCCESS;
+}
+
+static void walFreeObj(void *wal) {
+  SWal *pWal = wal;
+  wDebug("vgId:%d, wal:%p is freed", pWal->vgId, pWal);
+
+  taosClose(pWal->fd);
+  pthread_mutex_destroy(&pWal->mutex);
+  tfree(pWal);
+}
+
+static bool walNeedFsync(SWal *pWal) {
+  if (pWal->fsyncPeriod <= 0 || pWal->level != TAOS_WAL_FSYNC) {
+    return false;
+  }
+
+  if (tsWal.seq % pWal->fsyncSeq == 0) {
+    return true;
+  }
+
+  return false;
+}
+
+static void walUpdateSeq() {
+  taosMsleep(WAL_REFRESH_MS);
+  if (++tsWal.seq <= 0) {
+    tsWal.seq = 1;
+  }
+}
+
+static void walFsyncAll() {
+  SWal *pWal = taosIterateRef(tsWal.refId, NULL);
+  while (pWal) {
+    if (walNeedFsync(pWal)) {
+      wTrace("vgId:%d, do fsync, level:%d seq:%d rseq:%d", pWal->vgId, pWal->level, pWal->fsyncSeq, tsWal.seq);
+      int32_t code = fsync(pWal->fd);
+      if (code != 0) {
+        wError("vgId:%d, file:%s, failed to fsync since %s", pWal->vgId, pWal->name, strerror(code));
+      }
+    }
+    pWal = taosIterateRef(tsWal.refId, pWal);
+  }
+}
+
+static void *walThreadFunc(void *param) {
+  while (1) {
+    walUpdateSeq();
+    walFsyncAll();
+    if (tsWal.stop) break;
+  }
+
+  return NULL;
+}
+
+static int32_t walCreateThread() {
+  pthread_attr_t thAttr;
+  pthread_attr_init(&thAttr);
+  pthread_attr_setdetachstate(&thAttr, PTHREAD_CREATE_JOINABLE);
+
+  if (pthread_create(&tsWal.thread, &thAttr, walThreadFunc, NULL) != 0) {
+    wError("failed to create wal thread since %s", strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  pthread_attr_destroy(&thAttr);
+  wDebug("wal thread is launched");
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static void walStopThread() {
+  tsWal.stop = 1;
+  if (tsWal.thread) {
+    pthread_join(tsWal.thread, NULL);
+  }
+
+  wDebug("wal thread is stopped");
+}
diff --git a/src/wal/src/walUtil.c b/src/wal/src/walUtil.c
new file mode 100644
index 0000000000..e4d9a555b3
--- /dev/null
+++ b/src/wal/src/walUtil.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "walInt.h"
+
+int32_t walGetNextFile(SWal *pWal, int64_t *nextFileId) {
+  int64_t curFileId = *nextFileId;
+  int64_t minFileId = INT64_MAX;
+
+  DIR *dir = opendir(pWal->path);
+  if (dir == NULL) {
+    wError("vgId:%d, path:%s, failed to open since %s", pWal->vgId, pWal->path, strerror(errno));
+    return -1;
+  }
+
+  struct dirent *ent;
+  while ((ent = readdir(dir)) != NULL) {
+    char *name = ent->d_name;
+
+    if (strncmp(name, WAL_PREFIX, WAL_PREFIX_LEN) == 0) {
+      int64_t id = atoll(name + WAL_PREFIX_LEN);
+      if (id <= curFileId) continue;
+
+      if (id < minFileId) {
+        minFileId = id;
+      }
+    }
+  }
+  closedir(dir);
+
+  if (minFileId == INT64_MAX) return -1;
+
+  *nextFileId = minFileId;
+  wTrace("vgId:%d, path:%s, curFileId:%" PRId64 " nextFileId:%" PRId64, pWal->vgId, pWal->path, curFileId, *nextFileId);
+
+  return 0;
+}
+
+int32_t walGetOldFile(SWal *pWal, int64_t curFileId, int32_t minDiff, int64_t *oldFileId) {
+  int64_t minFileId = INT64_MAX;
+
+  DIR *dir = opendir(pWal->path);
+  if (dir == NULL) {
+    wError("vgId:%d, path:%s, failed to open since %s", pWal->vgId, pWal->path, strerror(errno));
+    return -1;
+  }
+
+  struct dirent *ent;
+  while ((ent = readdir(dir)) != NULL) {
+    char *name = ent->d_name;
+
+    if (strncmp(name, WAL_PREFIX, WAL_PREFIX_LEN) == 0) {
+      int64_t id = atoll(name + WAL_PREFIX_LEN);
+      if (id >= curFileId) continue;
+
+      minDiff--;
+      if (id < minFileId) {
+        minFileId = id;
+      }
+    }
+  }
+  closedir(dir);
+
+  if (minFileId == INT64_MAX) return -1;
+  if (minDiff > 0) return -1;
+
+  *oldFileId = minFileId;
+  wTrace("vgId:%d, path:%s, curFileId:%" PRId64 " oldFildId:%" PRId64, pWal->vgId, pWal->path, curFileId, *oldFileId);
+
+  return 0;
+}
+
+int32_t walGetNewFile(SWal *pWal, int64_t *newFileId) {
+  int64_t maxFileId = INT64_MIN;
+
+  DIR *dir = opendir(pWal->path);
+  if (dir == NULL) {
+    wError("vgId:%d, path:%s, failed to open since %s", pWal->vgId, pWal->path, strerror(errno));
+    return -1;
+  }
+
+  struct dirent *ent;
+  while ((ent = readdir(dir)) != NULL) {
+    char *name = ent->d_name;
+
+    if (strncmp(name, WAL_PREFIX, WAL_PREFIX_LEN) == 0) {
+      int64_t id = atoll(name + WAL_PREFIX_LEN);
+      if (id > maxFileId) {
+        maxFileId = id;
+      }
+    }
+  }
+  closedir(dir);
+
+  if (maxFileId == INT64_MIN) {
+    *newFileId = 0;
+  } else {
+    *newFileId = maxFileId;
+  }
+
+  wTrace("vgId:%d, path:%s, newFileId:%" PRId64, pWal->vgId, pWal->path, *newFileId);
+
+  return 0;
+}
\ No newline at end of file
diff --git a/src/wal/src/walWrite.c b/src/wal/src/walWrite.c
index 95587caa14..00dc3f4744 100644
--- a/src/wal/src/walWrite.c
+++ b/src/wal/src/walWrite.c
@@ -15,238 +15,95 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
+#include "talloc.h"
+#include "taoserror.h"
+#include "tchecksum.h"
 #include "twal.h"
 #include "walInt.h"
-#include "walMgmt.h"
-#include "tchecksum.h"
-#include "tutil.h"
-#include "ttimer.h"
-#include "taoserror.h"
-#include "twal.h"
-#include "tqueue.h"
 
+static int32_t walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp, char *name, int64_t fileId);
 
-typedef struct {
-  uint64_t version;
-  int      fd;
-  int      keep;
-  int      level;
-  int32_t  fsyncPeriod;
-  void    *timer;
-  void    *signature;
-  int      max;  // maximum number of wal files
-  uint32_t id;   // increase continuously
-  int      num;  // number of wal files
-  char     path[TSDB_FILENAME_LEN];
-  char     name[TSDB_FILENAME_LEN+16];
-  pthread_mutex_t mutex;
-} SWal;
-
-static void    *walTmrCtrl = NULL;
-static int     tsWalNum = 0;
-static pthread_once_t walModuleInit = PTHREAD_ONCE_INIT;
-static int  walHandleExistingFiles(const char *path);
-static int  walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp);
-static int  walRemoveWalFiles(const char *path);
-static void walProcessFsyncTimer(void *param, void *tmrId);
-static void walRelease(SWal *pWal);
-static int walGetMaxOldFileId(char *odir);
-
-static void walModuleInitFunc() {
-  walTmrCtrl = taosTmrInit(1000, 100, 300000, "WAL");
-  if (walTmrCtrl == NULL)
-    walModuleInit = PTHREAD_ONCE_INIT;
-  else
-    wDebug("WAL module is initialized");
-}
-
-static inline bool walNeedFsyncTimer(SWal *pWal) {
-  if (pWal->fsyncPeriod > 0 && pWal->level == TAOS_WAL_FSYNC) {
-    return true;
-  }
-  return false;
-}
-
-void *walOpen(const char *path, const SWalCfg *pCfg) {
-  SWal *pWal = calloc(sizeof(SWal), 1);
-  if (pWal == NULL) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return NULL;
-  }
-
-  pthread_once(&walModuleInit, walModuleInitFunc);
-  if (walTmrCtrl == NULL) {
-    free(pWal);
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return NULL;
-  }
-
-  atomic_add_fetch_32(&tsWalNum, 1);
-  pWal->fd = -1;
-  pWal->max = pCfg->wals;
-  pWal->id = 0;
-  pWal->num = 0;
-  pWal->level = pCfg->walLevel;
-  pWal->keep = pCfg->keep;
-  pWal->fsyncPeriod = pCfg->fsyncPeriod;
-  pWal->signature = pWal;
-  tstrncpy(pWal->path, path, sizeof(pWal->path));
-  pthread_mutex_init(&pWal->mutex, NULL);
-
-  if (walNeedFsyncTimer(pWal)) {
-    pWal->timer = taosTmrStart(walProcessFsyncTimer, pWal->fsyncPeriod, pWal, walTmrCtrl);
-    if (pWal->timer == NULL) {
-      terrno = TAOS_SYSTEM_ERROR(errno);
-      walRelease(pWal);
-      return NULL;
-    }
-  }
-
-  if (taosMkDir(path, 0755) != 0) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    wError("wal:%s, failed to create directory(%s)", path, strerror(errno));
-    walRelease(pWal);
-    pWal = NULL;
-  }
-
-  if (pCfg->keep == 1) return pWal;
-
-  if (walHandleExistingFiles(path) == 0) walRenew(pWal);
-
-  if (pWal && pWal->fd < 0) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    wError("wal:%s, failed to open(%s)", path, strerror(errno));
-    walRelease(pWal);
-    pWal = NULL;
-  }
-
-  if (pWal) wDebug("wal:%s, it is open, level:%d fsyncPeriod:%d", path, pWal->level, pWal->fsyncPeriod);
-  return pWal;
-}
-
-int walAlter(twalh wal, const SWalCfg *pCfg) {
-  SWal *pWal = wal;
-  if (pWal == NULL) {
-    return TSDB_CODE_WAL_APP_ERROR;
-  }
-
-  if (pWal->level == pCfg->walLevel && pWal->fsyncPeriod == pCfg->fsyncPeriod) {
-    wDebug("wal:%s, old walLevel:%d fsync:%d, new walLevel:%d fsync:%d not change", pWal->name, pWal->level,
-           pWal->fsyncPeriod, pCfg->walLevel, pCfg->fsyncPeriod);
-    return TSDB_CODE_SUCCESS;
-  }
-
-  wInfo("wal:%s, change old walLevel:%d fsync:%d, new walLevel:%d fsync:%d", pWal->name, pWal->level, pWal->fsyncPeriod,
-        pCfg->walLevel, pCfg->fsyncPeriod);
-
-  pthread_mutex_lock(&pWal->mutex);
-  pWal->level = pCfg->walLevel;
-  pWal->fsyncPeriod = pCfg->fsyncPeriod;
-  if (walNeedFsyncTimer(pWal)) {
-    wInfo("wal:%s, reset fsync timer, walLevel:%d fsyncPeriod:%d", pWal->name, pWal->level, pWal->fsyncPeriod);
-    taosTmrReset(walProcessFsyncTimer, pWal->fsyncPeriod, pWal, &pWal->timer, walTmrCtrl);
-  } else {
-    wInfo("wal:%s, stop fsync timer, walLevel:%d fsyncPeriod:%d", pWal->name, pWal->level, pWal->fsyncPeriod);
-    taosTmrStop(pWal->timer);
-    pWal->timer = NULL;
-  }
-  pthread_mutex_unlock(&pWal->mutex);
-
-  return TSDB_CODE_SUCCESS;
-}
-
-void walClose(void *handle) {
-  if (handle == NULL) return;
-
-  SWal *pWal = handle;
-  taosClose(pWal->fd);
-  if (pWal->timer) taosTmrStopA(&pWal->timer);
-
-  if (pWal->keep == 0) {
-    // remove all files in the directory
-    for (int i = 0; i < pWal->num; ++i) {
-      snprintf(pWal->name, sizeof(pWal->name), "%s/%s%d", pWal->path, walPrefix, pWal->id - i);
-      if (remove(pWal->name) < 0) {
-        wError("wal:%s, failed to remove", pWal->name);
-      } else {
-        wDebug("wal:%s, it is removed", pWal->name);
-      }
-    }
-  } else {
-    wDebug("wal:%s, it is closed and kept", pWal->name);
-  }
-
-  walRelease(pWal);
-}
-
-int walRenew(void *handle) {
+int32_t walRenew(void *handle) {
   if (handle == NULL) return 0;
-  SWal *pWal = handle;
 
-  terrno = 0;
+  SWal *  pWal = handle;
+  int32_t code = 0;
 
   pthread_mutex_lock(&pWal->mutex);
 
   if (pWal->fd >= 0) {
     close(pWal->fd);
-    pWal->id++;
-    wDebug("wal:%s, it is closed", pWal->name);
+    wDebug("vgId:%d, file:%s, it is closed", pWal->vgId, pWal->name);
   }
 
-  pWal->num++;
+  if (pWal->keep) {
+    pWal->fileId = 0;
+  } else {
+    if (walGetNewFile(pWal, &pWal->fileId) != 0) pWal->fileId = 0;
+    pWal->fileId++;
+  }
 
-  snprintf(pWal->name, sizeof(pWal->name), "%s/%s%d", pWal->path, walPrefix, pWal->id);
+  snprintf(pWal->name, sizeof(pWal->name), "%s/%s%" PRId64, pWal->path, WAL_PREFIX, pWal->fileId);
   pWal->fd = open(pWal->name, O_WRONLY | O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO);
 
   if (pWal->fd < 0) {
-    wError("wal:%s, failed to open(%s)", pWal->name, strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
+    code = TAOS_SYSTEM_ERROR(errno);
+    wError("vgId:%d, file:%s, failed to open since %s", pWal->vgId, pWal->name, strerror(errno));
   } else {
-    wDebug("wal:%s, it is created", pWal->name);
+    wDebug("vgId:%d, file:%s, it is created", pWal->vgId, pWal->name);
+  }
 
-    if (pWal->num > pWal->max) {
-      // remove the oldest wal file
-      char name[TSDB_FILENAME_LEN * 3];
-      snprintf(name, sizeof(name), "%s/%s%d", pWal->path, walPrefix, pWal->id - pWal->max);
-      if (remove(name) < 0) {
-        wError("wal:%s, failed to remove(%s)", name, strerror(errno));
+  if (!pWal->keep) {
+    // remove the oldest wal file
+    int64_t oldFileId = -1;
+    if (walGetOldFile(pWal, pWal->fileId, WAL_FILE_NUM, &oldFileId) == 0) {
+      char walName[WAL_FILE_LEN] = {0};
+      snprintf(walName, sizeof(walName), "%s/%s%" PRId64, pWal->path, WAL_PREFIX, oldFileId);
+
+      if (remove(walName) < 0) {
+        wError("vgId:%d, file:%s, failed to remove since %s", pWal->vgId, walName, strerror(errno));
       } else {
-        wDebug("wal:%s, it is removed", name);
+        wDebug("vgId:%d, file:%s, it is removed", pWal->vgId, walName);
       }
-
-      pWal->num--;
     }
   }
 
   pthread_mutex_unlock(&pWal->mutex);
 
-  return terrno;
+  return code;
 }
 
-int walWrite(void *handle, SWalHead *pHead) {
-  SWal *pWal = handle;
-  if (pWal == NULL) return -1;
+int32_t walWrite(void *handle, SWalHead *pHead) {
+  if (handle == NULL) return -1;
 
-  terrno = 0;
+  SWal *  pWal = handle;
+  int32_t code = 0;
 
   // no wal
+  if (pWal->fd <= 0) return 0;
   if (pWal->level == TAOS_WAL_NOLOG) return 0;
   if (pHead->version <= pWal->version) return 0;
 
-  pHead->signature = walSignature;
+  pHead->signature = WAL_SIGNATURE;
   taosCalcChecksumAppend(0, (uint8_t *)pHead, sizeof(SWalHead));
-  int contLen = pHead->len + sizeof(SWalHead);
+  int32_t contLen = pHead->len + sizeof(SWalHead);
+
+  pthread_mutex_lock(&pWal->mutex);
 
   if (taosTWrite(pWal->fd, pHead, contLen) != contLen) {
-    wError("wal:%s, failed to write(%s)", pWal->name, strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return terrno;
+    code = TAOS_SYSTEM_ERROR(errno);
+    wError("vgId:%d, file:%s, failed to write since %s", pWal->vgId, pWal->name, strerror(errno));
   } else {
+    wTrace("vgId:%d, fileId:%" PRId64 " fd:%d, write wal ver:%" PRId64 ", head ver:%" PRIu64 ", len:%d ", pWal->vgId,
+           pWal->fileId, pWal->fd, pWal->version, pHead->version, pHead->len);
     pWal->version = pHead->version;
   }
+
+  pthread_mutex_unlock(&pWal->mutex);
+
   ASSERT(contLen == pHead->len + sizeof(SWalHead));
 
-  return 0;
+  return code;
 }
 
 void walFsync(void *handle) {
@@ -255,295 +112,203 @@ void walFsync(void *handle) {
 
   if (pWal->fsyncPeriod == 0) {
     if (fsync(pWal->fd) < 0) {
-      wError("wal:%s, fsync failed(%s)", pWal->name, strerror(errno));
+      wError("vgId:%d, file:%s, fsync failed since %s", pWal->vgId, pWal->name, strerror(errno));
     }
   }
 }
 
-int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int)) {
-  SWal    *pWal = handle;
-  struct   dirent *ent;
-  int      count = 0;
-  uint32_t maxId = 0, minId = -1, index =0;
+int32_t walRestore(void *handle, void *pVnode, int32_t (*writeFp)(void *, void *, int32_t)) {
+  if (handle == NULL) return -1;
 
-  terrno = 0;
-  int  plen = strlen(walPrefix);
-  char opath[TSDB_FILENAME_LEN + 5];
+  SWal *  pWal = handle;
+  int32_t count = 0;
+  int32_t code = 0;
+  int64_t fileId = -1;
 
-  int slen = snprintf(opath, sizeof(opath), "%s", pWal->path);
-  if (pWal->keep == 0) strcpy(opath + slen, "/old");
+  while ((code = walGetNextFile(pWal, &fileId)) >= 0) {
+    if (fileId == pWal->fileId) continue;
 
-  DIR *dir = opendir(opath);
-  if (dir == NULL && errno == ENOENT) return 0;
-  if (dir == NULL) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return terrno;
-  }
+    char walName[WAL_FILE_LEN];
+    snprintf(walName, sizeof(pWal->name), "%s/%s%" PRId64, pWal->path, WAL_PREFIX, fileId);
 
-  while ((ent = readdir(dir)) != NULL) {
-    if (strncmp(ent->d_name, walPrefix, plen) == 0) {
-      index = atol(ent->d_name + plen);
-      if (index > maxId) maxId = index;
-      if (index < minId) minId = index;
-      count++;
+    wDebug("vgId:%d, file:%s, will be restored", pWal->vgId, walName);
+    int32_t code = walRestoreWalFile(pWal, pVnode, writeFp, walName, fileId);
+    if (code != TSDB_CODE_SUCCESS) {
+      wError("vgId:%d, file:%s, failed to restore since %s", pWal->vgId, walName, tstrerror(code));
+      continue;
     }
+
+    if (!pWal->keep) {
+      wDebug("vgId:%d, file:%s, restore success, remove this file", pWal->vgId, walName);
+      remove(walName);
+    } else {
+      wDebug("vgId:%d, file:%s, restore success and keep it", pWal->vgId, walName);
+    }
+
+    count++;
   }
 
-  closedir(dir);
+  if (!pWal->keep) return TSDB_CODE_SUCCESS;
 
   if (count == 0) {
-    if (pWal->keep) terrno = walRenew(pWal);
-    return terrno;
-  }
-
-  if (count != (maxId - minId + 1)) {
-    wError("wal:%s, messed up, count:%d max:%d min:%d", opath, count, maxId, minId);
-    terrno = TSDB_CODE_WAL_APP_ERROR;
+    wDebug("vgId:%d, file:%s not exist, renew it", pWal->vgId, pWal->name);
+    return walRenew(pWal);
   } else {
-    wDebug("wal:%s, %d files will be restored", opath, count);
-
-    for (index = minId; index <= maxId; ++index) {
-      snprintf(pWal->name, sizeof(pWal->name), "%s/%s%d", opath, walPrefix, index);
-      terrno = walRestoreWalFile(pWal, pVnode, writeFp);
-      if (terrno < 0) continue;
+    // open the existing WAL file in append mode
+    pWal->fileId = 0;
+    snprintf(pWal->name, sizeof(pWal->name), "%s/%s%" PRId64, pWal->path, WAL_PREFIX, pWal->fileId);
+    pWal->fd = open(pWal->name, O_WRONLY | O_CREAT | O_APPEND, S_IRWXU | S_IRWXG | S_IRWXO);
+    if (pWal->fd < 0) {
+      wError("vgId:%d, file:%s, failed to open since %s", pWal->vgId, pWal->name, strerror(errno));
+      return TAOS_SYSTEM_ERROR(errno);
     }
+    wDebug("vgId:%d, file:%s open success", pWal->vgId, pWal->name);
   }
 
-  if (terrno == 0) {
-    if (pWal->keep == 0) {
-      terrno = walRemoveWalFiles(opath);
-      if (terrno == 0) {
-        if (remove(opath) < 0) {
-          wError("wal:%s, failed to remove directory(%s)", opath, strerror(errno));
-          terrno = TAOS_SYSTEM_ERROR(errno);
-        }
-      }
-    } else {
-      // open the existing WAL file in append mode
-      pWal->num = count;
-      pWal->id = maxId;
-      snprintf(pWal->name, sizeof(pWal->name), "%s/%s%d", opath, walPrefix, maxId);
-      pWal->fd = open(pWal->name, O_WRONLY | O_CREAT | O_APPEND, S_IRWXU | S_IRWXG | S_IRWXO);
-      if (pWal->fd < 0) {
-        wError("wal:%s, failed to open file(%s)", pWal->name, strerror(errno));
-        terrno = TAOS_SYSTEM_ERROR(errno);
-      }
-    }
-  }
-
-  return terrno;
+  return TSDB_CODE_SUCCESS;
 }
 
-int walGetWalFile(void *handle, char *name, uint32_t *index) {
-  SWal *  pWal = handle;
-  int     code = 1;
-  int32_t first = 0;
+int32_t walGetWalFile(void *handle, char *fileName, int64_t *fileId) {
+  if (handle == NULL) return -1;
+  SWal *pWal = handle;
 
-  name[0] = 0;
-  if (pWal == NULL || pWal->num == 0) return 0;
+  // for keep
+  if (*fileId == 0) *fileId = -1;
 
   pthread_mutex_lock(&(pWal->mutex));
 
-  first = pWal->id + 1 - pWal->num;
-  if (*index == 0) *index = first;  // set to first one
-
-  if (*index < first && *index > pWal->id) {
-    code = -1;  // index out of range
-  } else {
-    sprintf(name, "wal/%s%d", walPrefix, *index);
-    code = (*index == pWal->id) ? 0 : 1;
+  int32_t code = walGetNextFile(pWal, fileId);
+  if (code >= 0) {
+    sprintf(fileName, "wal/%s%" PRId64, WAL_PREFIX, *fileId);
+    code = (*fileId == pWal->fileId) ? 0 : 1;
   }
 
+  wTrace("vgId:%d, get wal file, code:%d curId:%" PRId64 " outId:%" PRId64, pWal->vgId, code, pWal->fileId, *fileId);
   pthread_mutex_unlock(&(pWal->mutex));
 
   return code;
 }
 
-static void walRelease(SWal *pWal) {
-  pthread_mutex_destroy(&pWal->mutex);
-  pWal->signature = NULL;
-  free(pWal);
-
-  if (atomic_sub_fetch_32(&tsWalNum, 1) == 0) {
-    if (walTmrCtrl) taosTmrCleanUp(walTmrCtrl);
-    walTmrCtrl = NULL;
-    walModuleInit = PTHREAD_ONCE_INIT;
-    wDebug("WAL module is cleaned up");
-  }
+static void walFtruncate(SWal *pWal, int32_t fd, int64_t offset) {
+  taosFtruncate(fd, offset);
+  fsync(fd);
 }
 
-static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
-  char *name = pWal->name;
-  int   size = 1024 * 1024;  // default 1M buffer size
-
-  terrno = 0;
-  char *buffer = malloc(size);
-  if (buffer == NULL) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return terrno;
-  }
-
-  SWalHead *pHead = (SWalHead *)buffer;
-
-  int fd = open(name, O_RDWR);
-  if (fd < 0) {
-    wError("wal:%s, failed to open for restore(%s)", name, strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    free(buffer);
-    return terrno;
-  }
-
-  wDebug("wal:%s, start to restore", name);
-
-  size_t offset = 0;
+static int32_t walSkipCorruptedRecord(SWal *pWal, SWalHead *pHead, int32_t fd, int64_t *offset) {
+  int64_t pos = *offset;
   while (1) {
-    int ret = taosTRead(fd, pHead, sizeof(SWalHead));
+    pos++;
+
+    if (lseek(fd, pos, SEEK_SET) < 0) {
+      wError("vgId:%d, failed to seek from corrupted wal file since %s", pWal->vgId, strerror(errno));
+      return TSDB_CODE_WAL_FILE_CORRUPTED;
+    }
+
+    if (taosTRead(fd, pHead, sizeof(SWalHead)) <= 0) {
+      wError("vgId:%d, read to end of corrupted wal file, offset:%" PRId64, pWal->vgId, pos);
+      return TSDB_CODE_WAL_FILE_CORRUPTED;
+    }
+
+    if (pHead->signature != WAL_SIGNATURE) {
+      continue;
+    }
+
+    if (taosCheckChecksumWhole((uint8_t *)pHead, sizeof(SWalHead))) {
+      wInfo("vgId:%d, wal head cksum check passed, offset:%" PRId64, pWal->vgId, pos);
+      *offset = pos;
+      return TSDB_CODE_SUCCESS;
+    }
+  }
+
+  return TSDB_CODE_WAL_FILE_CORRUPTED;
+}
+
+static int32_t walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp, char *name, int64_t fileId) {
+  int32_t size = WAL_MAX_SIZE;
+  void *  buffer = tmalloc(size);
+  if (buffer == NULL) {
+    wError("vgId:%d, file:%s, failed to open for restore since %s", pWal->vgId, name, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  int32_t fd = open(name, O_RDWR);
+  if (fd < 0) {
+    wError("vgId:%d, file:%s, failed to open for restore since %s", pWal->vgId, name, strerror(errno));
+    tfree(buffer);
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  wDebug("vgId:%d, file:%s, start to restore", pWal->vgId, name);
+
+  int32_t   code = TSDB_CODE_SUCCESS;
+  int64_t   offset = 0;
+  SWalHead *pHead = buffer;
+
+  while (1) {
+    int32_t ret = taosTRead(fd, pHead, sizeof(SWalHead));
     if (ret == 0) break;
 
     if (ret < 0) {
-      wError("wal:%s, failed to read wal head part since %s", name, strerror(errno));
-      terrno = TAOS_SYSTEM_ERROR(errno);
+      wError("vgId:%d, file:%s, failed to read wal head since %s", pWal->vgId, name, strerror(errno));
+      code = TAOS_SYSTEM_ERROR(errno);
       break;
     }
 
     if (ret < sizeof(SWalHead)) {
-      wError("wal:%s, failed to read head, ret:%d, skip the rest of file", name, ret);
-      taosFtruncate(fd, offset);
-      fsync(fd);
+      wError("vgId:%d, file:%s, failed to read wal head, ret is %d", pWal->vgId, name, ret);
+      walFtruncate(pWal, fd, offset);
       break;
     }
 
     if (!taosCheckChecksumWhole((uint8_t *)pHead, sizeof(SWalHead))) {
-      wWarn("wal:%s, cksum is messed up, skip the rest of file", name);
-      terrno = TSDB_CODE_WAL_FILE_CORRUPTED;
-      ASSERT(false);
-      break;
+      wError("vgId:%d, file:%s, wal head cksum is messed up, ver:%" PRIu64 " len:%d offset:%" PRId64, pWal->vgId, name,
+             pHead->version, pHead->len, offset);
+      code = walSkipCorruptedRecord(pWal, pHead, fd, &offset);
+      if (code != TSDB_CODE_SUCCESS) {
+        walFtruncate(pWal, fd, offset);
+        break;
+      }
     }
 
     if (pHead->len > size - sizeof(SWalHead)) {
       size = sizeof(SWalHead) + pHead->len;
       buffer = realloc(buffer, size);
       if (buffer == NULL) {
-        terrno = TAOS_SYSTEM_ERROR(errno);
+        wError("vgId:%d, file:%s, failed to open for restore since %s", pWal->vgId, name, strerror(errno));
+        code = TAOS_SYSTEM_ERROR(errno);
         break;
       }
 
-      pHead = (SWalHead *)buffer;
+      pHead = buffer;
     }
 
     ret = taosTRead(fd, pHead->cont, pHead->len);
     if (ret < 0) {
-      wError("wal:%s failed to read wal body part since %s", name, strerror(errno));
-      terrno = TAOS_SYSTEM_ERROR(errno);
+      wError("vgId:%d, file:%s, failed to read wal body since %s", pWal->vgId, name, strerror(errno));
+      code = TAOS_SYSTEM_ERROR(errno);
       break;
     }
 
     if (ret < pHead->len) {
-      wError("wal:%s, failed to read body, len:%d ret:%d, skip the rest of file", name, pHead->len, ret);
-      taosFtruncate(fd, offset);
-      fsync(fd);
-      break;
+      wError("vgId:%d, file:%s, failed to read wal body, ret:%d len:%d", pWal->vgId, name, ret, pHead->len);
+      offset += sizeof(SWalHead);
+      continue;
     }
 
     offset = offset + sizeof(SWalHead) + pHead->len;
 
+    wTrace("vgId:%d, fileId:%" PRId64 ", restore wal ver:%" PRIu64 ", head ver:%" PRIu64 " len:%d", pWal->vgId, fileId,
+           pWal->version, pHead->version, pHead->len);
+
     if (pWal->keep) pWal->version = pHead->version;
+
     (*writeFp)(pVnode, pHead, TAOS_QTYPE_WAL);
   }
 
   close(fd);
-  free(buffer);
+  tfree(buffer);
 
-  return terrno;
-}
-
-int walHandleExistingFiles(const char *path) {
-  char   oname[TSDB_FILENAME_LEN * 3];
-  char   nname[TSDB_FILENAME_LEN * 3];
-  char   opath[TSDB_FILENAME_LEN];
-
-  snprintf(opath, sizeof(opath), "%s/old", path);
-
-  struct dirent *ent;
-  DIR   *dir = opendir(path);
-  int    plen = strlen(walPrefix);
-  terrno = 0;
-
-  int midx = walGetMaxOldFileId(opath);
-  int count = 0;
-  while ((ent = readdir(dir)) != NULL) {
-    if (strncmp(ent->d_name, walPrefix, plen) == 0) {
-      midx++;
-      snprintf(oname, sizeof(oname), "%s/%s", path, ent->d_name);
-      snprintf(nname, sizeof(nname), "%s/old/wal%d", path, midx);
-      if (taosMkDir(opath, 0755) != 0) {
-        wError("wal:%s, failed to create directory:%s(%s)", oname, opath, strerror(errno));
-        terrno = TAOS_SYSTEM_ERROR(errno);
-        break;
-      }
-
-      if (rename(oname, nname) < 0) {
-        wError("wal:%s, failed to move to new:%s", oname, nname);
-        terrno = TAOS_SYSTEM_ERROR(errno);
-        break;
-      }
-
-      count++;
-    }
-
-    wDebug("wal:%s, %d files are moved for restoration", path, count);
-  }
-
-  closedir(dir);
-  return terrno;
-}
-
-static int walRemoveWalFiles(const char *path) {
-  int  plen = strlen(walPrefix);
-  char name[TSDB_FILENAME_LEN * 3];
-
-  terrno = 0;
-
-  struct dirent *ent;
-  DIR *dir = opendir(path);
-  if (dir == NULL && errno == ENOENT) return 0;
-  if (dir == NULL) {
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return terrno;
-  }
-
-  while ((ent = readdir(dir)) != NULL) {
-    if (strncmp(ent->d_name, walPrefix, plen) == 0) {
-      snprintf(name, sizeof(name), "%s/%s", path, ent->d_name);
-      if (remove(name) < 0) {
-        wError("wal:%s, failed to remove(%s)", name, strerror(errno));
-        terrno = TAOS_SYSTEM_ERROR(errno);
-      }
-    }
-  }
-
-  closedir(dir);
-
-  return terrno;
-}
-
-static void walProcessFsyncTimer(void *param, void *tmrId) {
-  SWal *pWal = param;
-
-  if (pWal->signature != pWal) return;
-  if (pWal->fd < 0) return;
-
-  if (fsync(pWal->fd) < 0) {
-    wError("wal:%s, fsync failed(%s)", pWal->name, strerror(errno));
-  }
-
-  if (walNeedFsyncTimer(pWal)) {
-    pWal->timer = taosTmrStart(walProcessFsyncTimer, pWal->fsyncPeriod, pWal, walTmrCtrl);
-  } else {
-    wInfo("wal:%s, stop fsync timer for walLevel:%d fsyncPeriod:%d", pWal->name, pWal->level, pWal->fsyncPeriod);
-    taosTmrStop(pWal->timer);
-    pWal->timer = NULL;
-  }
+  return code;
 }
 
 int64_t walGetVersion(twalh param) {
@@ -552,29 +317,3 @@ int64_t walGetVersion(twalh param) {
 
   return pWal->version;
 }
-
-static int walGetMaxOldFileId(char *odir) {
-  int            midx = 0;
-  DIR *          dir = NULL;
-  struct dirent *dp = NULL;
-  int            plen = strlen(walPrefix);
-
-  if (access(odir, F_OK) != 0) return midx;
-
-  dir = opendir(odir);
-  if (dir == NULL) {
-    wError("failed to open directory %s since %s", odir, strerror(errno));
-    terrno = TAOS_SYSTEM_ERROR(errno);
-    return -1;
-  }
-
-  while ((dp = readdir(dir)) != NULL) {
-    if (strncmp(dp->d_name, walPrefix, plen) == 0) {
-      int idx = atol(dp->d_name + plen);
-      if (midx < idx) midx = idx;
-    }
-  }
-
-  closedir(dir);
-  return midx;
-}
\ No newline at end of file
diff --git a/src/wal/test/waltest.c b/src/wal/test/waltest.c
index bbee1347b8..186f2ef5ff 100644
--- a/src/wal/test/waltest.c
+++ b/src/wal/test/waltest.c
@@ -115,17 +115,17 @@ int main(int argc, char *argv[]) {
 
   printf("%d wal files are written\n", total);
 
-  uint32_t index = 0;
-  char     name[256];
+  int64_t index = 0;
+  char    name[256];
 
   while (1) {
     int code = walGetWalFile(pWal, name, &index);
     if (code == -1) {
-      printf("failed to get wal file, index:%d\n", index);
+      printf("failed to get wal file, index:%" PRId64 "\n", index);
       break;
     }
 
-    printf("index:%d wal:%s\n", index, name);
+    printf("index:%" PRId64 " wal:%s\n", index, name);
     if (code == 0) break;
 
     index++;
diff --git a/tests/examples/go/taosdemo.go b/tests/examples/go/taosdemo.go
index 14a67b93d3..2c3a7d09b6 100644
--- a/tests/examples/go/taosdemo.go
+++ b/tests/examples/go/taosdemo.go
@@ -87,7 +87,7 @@ func init() {
 
 func printAllArgs() {
 	fmt.Printf("\n============= args parse result: =============\n")
-	fmt.Printf("dbName:               %v\n", configPara.hostName)
+	fmt.Printf("hostName:               %v\n", configPara.hostName)
 	fmt.Printf("serverPort:           %v\n", configPara.serverPort)
 	fmt.Printf("usr:                  %v\n", configPara.user)
 	fmt.Printf("password:             %v\n", configPara.password)
diff --git a/tests/pytest/insert/restfulInsert.py b/tests/pytest/insert/restfulInsert.py
new file mode 100644
index 0000000000..a6c9b074e1
--- /dev/null
+++ b/tests/pytest/insert/restfulInsert.py
@@ -0,0 +1,83 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import requests
+import threading
+import random
+import time
+
+class RestfulInsert:
+    def init(self):
+        self.header = {'Authorization': 'Basic cm9vdDp0YW9zZGF0YQ=='}
+        self.url = "http://127.0.0.1:6041/rest/sql"
+        self.ts = 1500000000000
+        self.numOfThreads = 20
+        self.numOfTables = 10000
+        self.recordsPerTable = 10000
+        self.batchSize = 1000
+        self.tableNamePerfix = 't'
+    
+    def createTable(self, threadID):
+        tablesPerThread = int (self.numOfTables / self.numOfThreads)
+        print("create table %d to %d" % (tablesPerThread * threadID, tablesPerThread * (threadID + 1) - 1))
+        for i in range(tablesPerThread):
+            tableID = threadID * tablesPerThread
+            name = 'beijing' if tableID % 2 == 0 else 'shanghai'
+            data = "create table test.%s%d using test.meters tags(%d, '%s')" % (self.tableNamePerfix, tableID + i, tableID + i, name)            
+            requests.post(self.url, data, headers = self.header)
+
+    def insertData(self, threadID):        
+        print("thread %d started" % threadID)
+        tablesPerThread = int (self.numOfTables / self.numOfThreads)        
+        for i in range(tablesPerThread):
+            tableID = i + threadID * tablesPerThread
+            start = self.ts
+            for j in range(int(self.recordsPerTable / self.batchSize)):
+                data = "insert into test.%s%d values" % (self.tableNamePerfix, tableID)
+                for k in range(self.batchSize):
+                    data += "(%d, %d, %d, %d)" %  (start + j * self.batchSize + k, random.randint(1, 100), random.randint(1, 100), random.randint(1, 100))                
+                requests.post(self.url, data, headers = self.header)
+
+    def run(self):
+        data = "drop database if exists test"
+        requests.post(self.url, data, headers = self.header)
+        data = "create database test"
+        requests.post(self.url, data, headers = self.header)
+        data = "create table test.meters(ts timestamp, f1 int, f2 int, f3 int) tags(id int, loc nchar(20))"
+        requests.post(self.url, data, headers = self.header)
+
+        threads = []
+        startTime = time.time()    
+        for i in range(self.numOfThreads):
+            thread = threading.Thread(target=self.createTable, args=(i,))
+            thread.start()
+            threads.append(thread)
+        for i in range(self.numOfThreads):
+            threads[i].join()
+        print("createing %d tables takes %d seconds" % (self.numOfTables, (time.time() - startTime)))
+
+        print("inserting data =======")
+        threads = []
+        startTime = time.time()
+        for i in range(self.numOfThreads):
+            thread = threading.Thread(target=self.insertData, args=(i,))
+            thread.start()
+            threads.append(thread)
+        
+        for i in range(self.numOfThreads):
+            threads[i].join()
+        print("inserting %d records takes %d seconds" % (self.numOfTables * self.recordsPerTable, (time.time() - startTime)))
+
+ri = RestfulInsert()
+ri.init()
+ri.run()
\ No newline at end of file
diff --git a/tests/pytest/query/sliding.py b/tests/pytest/query/sliding.py
new file mode 100644
index 0000000000..810d90117a
--- /dev/null
+++ b/tests/pytest/query/sliding.py
@@ -0,0 +1,63 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+import random
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+        self.ts = 1500000000000
+
+    def run(self):
+        tdSql.prepare()
+        
+        tdSql.execute("create table meters(ts timestamp, col1 int) tags(id int, loc nchar(20))")
+        sql = "insert into t0 using meters tags(1, 'beijing') values"
+        for i in range(100):
+            sql += "(%d, %d)" % (self.ts + i * 1000, random.randint(1, 100))        
+        tdSql.execute(sql)   
+
+        sql = "insert into t1 using meters tags(2, 'shanghai') values"
+        for i in range(100):
+            sql += "(%d, %d)" % (self.ts + i * 1000, random.randint(1, 100))        
+        tdSql.execute(sql)
+        
+        tdSql.query("select count(*) from meters interval(10s) sliding(5s)")
+        tdSql.checkRows(21)
+
+        tdSql.error("select count(*) from meters sliding(5s)")
+
+        tdSql.error("select count(*) from meters sliding(5s) interval(10s)")
+
+        tdSql.error("select * from meters sliding(5s) order by ts desc")
+                
+        tdSql.query("select count(*) from meters group by loc")
+        tdSql.checkRows(2)
+
+        tdSql.error("select * from meters group by loc sliding(5s)")    
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/script/general/parser/join_multivnode.sim b/tests/script/general/parser/join_multivnode.sim
index 5e4a0990c1..102d5ba93f 100644
--- a/tests/script/general/parser/join_multivnode.sim
+++ b/tests/script/general/parser/join_multivnode.sim
@@ -134,13 +134,66 @@ sql select join_mt0.ts, join_mt1.t1, join_mt0.t1, join_mt1.tbname, join_mt0.tbna
 
 #1970-01-01 08:01:40.800 |                    10 |              45.000000000 |         0 |     true |     false |           0 |
 #1970-01-01 08:01:40.790 |                    10 |             945.000000000 |        90 |     true |      true |           0 |
-
 sql select count(join_mt0.c1), sum(join_mt1.c2), first(join_mt0.c5), last(join_mt1.c7), first(join_mt1.c7) from join_mt0, join_mt1 where join_mt0.t1=join_mt1.t1 and join_mt0.ts=join_mt1.ts interval(10a) group by join_mt0.t1 order by join_mt0.ts desc limit 20 offset 19;
-if $rows != 100 then
+if $rows != 20 then
   return -1
 endi
 
-# c5 is null ! error
+if $data00 != @70-01-01 08:01:40.800@ then
+  return -1
+endi
+
+if $data01 != 10 then
+  return -1
+endi
+
+if $data02 != 45.000000000 then
+  return -1
+endi
+
+if $data03 != 0 then
+  return -1
+endi
+
+if $data04 != 1 then
+  return -1
+endi
+
+if $data05 != 0 then
+  return -1
+endi
+
+if $data06 != 0 then
+  return -1
+endi
+
+if $data10 != @70-01-01 08:01:40.790@ then
+  return -1
+endi
+
+if $data11 != 10 then
+  return -1
+endi
+
+if $data12 != 945.000000000 then
+  return -1
+endi
+
+if $data13 != 90 then
+  return -1
+endi
+
+if $data14 != 1 then
+  return -1
+endi
+
+if $data15 != 1 then
+  return -1
+endi
+
+if $data16 != 0 then
+  return -1
+endi
 
 sql select count(join_mt0.c1), sum(join_mt0.c2)/count(*), avg(c2), first(join_mt0.c5), last(c7) from join_mt0  interval(10a) group by join_mt0.t1 order by join_mt0.ts desc;
 if $rows != 100 then
diff --git a/tests/script/unique/dnode/offline1.sim b/tests/script/unique/dnode/offline1.sim
index 02d03dee97..beebbfda60 100644
--- a/tests/script/unique/dnode/offline1.sim
+++ b/tests/script/unique/dnode/offline1.sim
@@ -49,7 +49,7 @@ print dnode1 $data4_2
 if $data4_1 != ready then
   return -1
 endi
-if $data4_2 != offline then
+if $data4_2 == ready then
   return -1
 endi