Merge branch 'develop' into feature/query

2020-10-26 14:49:48 +08:00 · 2020-10-26 14:49:48 +08:00 · 92eafa0719
parent b1c2ff74b7 edadef714e
commit 92eafa0719
74 changed files with 3046 additions and 1448 deletions
--- a/4
+++ b/4
@ -9,7 +9,7 @@ pipeline {
      stage('Parallel test stage') {
      parallel {
        stage('pytest') {
-          agent{label 'master'}
+          agent{label '184'}
          steps {
            sh '''
            date
@ -34,7 +34,7 @@ pipeline {
          }
        }
        stage('test_b1') {
-          agent{label '184'}
+          agent{label 'master'}
          steps {
            sh '''
            cd ${WKC}
--- a/alert/README.md
+++ b/alert/README.md
@ -61,7 +61,7 @@ The use of each configuration item is:

 * **port**: This is the `http` service port which enables other application to manage rules by `restful API`.
 * **database**: rules are stored in a `sqlite` database, this is the path of the database file (if the file does not exist, the alert application creates it automatically).
-* **tdengine**: connection string of `TDEngine` server, note in most cases the database information should be put in a rule, thus it should NOT be included here.
+* **tdengine**: connection string of `TDEngine` server, note the database name should be put in the `sql` field of a rule in most cases, thus it should NOT be included in the string.
 * **log > level**: log level, could be `production` or `debug`.
 * **log > path**: log output file path.
 * **receivers > alertManager**: the alert application pushes alerts to `AlertManager` at this URL.
--- a/alert/README_cn.md
+++ b/alert/README_cn.md
@ -58,7 +58,7 @@ $ go build

 * **port**：报警监测程序支持使用 `restful API` 对规则进行管理，这个参数用于配置 `http` 服务的侦听端口。
 * **database**：报警监测程序将规则保存到了一个 `sqlite` 数据库中，这个参数用于指定数据库文件的路径（不需要提前创建这个文件，如果它不存在，程序会自动创建它）。
-* **tdengine**：`TDEngine` 的连接信息，一般来说，数据库信息应该在报警规则中指定，所以这里 **不** 应包含这一部分信息。
+* **tdengine**：`TDEngine` 的连接字符串，一般来说，数据库名应该在报警规则的 `sql` 语句中指定，所以这个字符串中 **不** 应包含数据库名。
 * **log > level**：日志的记录级别，可选 `production` 或 `debug`。
 * **log > path**：日志文件的路径。
 * **receivers > alertManager**：报警监测程序会将报警推送到 `AlertManager`，在这里指定 `AlertManager` 的接收地址。
--- a/cmake/version.inc
+++ b/cmake/version.inc
@ -4,7 +4,7 @@ PROJECT(TDengine)
 IF (DEFINED VERNUMBER)
  SET(TD_VER_NUMBER ${VERNUMBER})
 ELSE ()
-  SET(TD_VER_NUMBER "2.0.5.1")
+  SET(TD_VER_NUMBER "2.0.6.0")
 ENDIF ()

 IF (DEFINED VERCOMPATIBLE)
--- a/documentation/tdenginedocs-cn/advanced-features/index.html
+++ b/documentation/tdenginedocs-cn/advanced-features/index.html
@ -51,8 +51,8 @@ INTERVAL(1M)</code></pre>
 <li><p>mseconds：查询数据库更新的时间间隔，单位为毫秒。一般设置为1000毫秒。返回值为指向TDengine_SUB 结构的指针，如果返回为空，表示失败。</p></li>
 </ul><li><p><code>TAOS_ROW taos_consume(TAOS_SUB *tsub)</code>
 </p><p>该函数用来获取订阅的结果，用户应用程序将其置于一个无限循环语句。如果数据库有新记录到达，该API将返回该最新的记录。如果没有新的记录，该API将阻塞。如果返回值为空，说明系统出错。参数说明：</p></li><ul><li><p>tsub：taos_subscribe的结构体指针。</p></li></ul><li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code></p><p>取消订阅。应用程序退出时，务必调用该函数以避免资源泄露。</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code></p><p>获取返回的一行记录中数据包含多少列。</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_SUB *tsub)</code></p><p>获取每列数据的属性（数据类型、名字、长度），与taos_num_subfileds配合使用，可解析返回的每行数据。</p></li></ul>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code></p><p>获取返回的一行记录中数据包含多少列。</p></li>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_SUB *tsub)</code></p><p>获取每列数据的属性（数据类型、名字、长度），与taos_num_subfileds配合使用，可解析返回的每行数据。</p></li></ul>
 <p>示例代码：请看安装包中的的示范程序</p>
 <a class='anchor' id='缓存-(Cache)'></a><h2>缓存 (Cache)</h2>
 <p>TDengine采用时间驱动缓存管理策略（First-In-First-Out，FIFO），又称为写驱动的缓存管理机制。这种策略有别于读驱动的数据缓存模式（Least-Recent-Use，LRU），直接将最近写入的数据保存在系统的缓存中。当缓存达到临界值的时候，将最早的数据批量写入磁盘。一般意义上来说，对于物联网数据的使用，用户最为关心最近产生的数据，即当前状态。TDengine充分利用了这一特性，将最近到达的（当前状态）数据保存在缓存中。</p>
--- a/documentation/tdenginedocs-cn/connector/index.html
+++ b/documentation/tdenginedocs-cn/connector/index.html
@ -64,9 +64,9 @@
 <p>该API用来获取最新消息，应用程序一般会将其置于一个无限循环语句中。其中参数tsub是taos_subscribe的返回值。如果数据库有新的记录，该API将返回，返回参数是一行记录。如果没有新的记录，该API将阻塞。如果返回值为空，说明系统出错，需要检查系统是否还在正常运行。</p></li>
 <li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code></p>
 <p>该API用于取消订阅，参数tsub是taos_subscribe的返回值。应用程序退出时，需要调用该API，否则有资源泄露。</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code></p>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code></p>
 <p>该API用来获取返回的一排数据中数据的列数</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_RES *res)</code></p>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_RES *res)</code></p>
 <p>该API用来获取每列数据的属性（数据类型、名字、字节数），与taos_num_subfileds配合使用，可用来解析返回的一排数据。</p></li>
 </ul>
 <a class='anchor' id='Java-Connector'></a><h2>Java Connector</h2>
@ -259,4 +259,4 @@ conn.close()
    _ "taosSql"
 )</code></pre>
 <p>taosSql驱动包内采用cgo模式，调用了TDengine的C/C++同步接口，与TDengine进行交互，因此，在数据库操作执行完成之前，客户端应用将处于阻塞状态。单个数据库连接，在同一时刻只能有一个线程调用API。客户应用可以建立多个连接，进行多线程的数据写入或查询处理。</p>
-<p>更多使用的细节，请参考下载目录中的示例源码。</p><a href='../index.html'>回去</a></section></main></div><?php include($s.'/footer.php'); ?><script>$('pre').addClass('prettyprint linenums');PR.prettyPrint()</script><script src='lib/docs/liner.js'></script></body></html>
+<p>更多使用的细节，请参考下载目录中的示例源码。</p><a href='../index.html'>回去</a></section></main></div><?php include($s.'/footer.php'); ?><script>$('pre').addClass('prettyprint linenums');PR.prettyPrint()</script><script src='lib/docs/liner.js'></script></body></html>
--- a/documentation/tdenginedocs-en/connector/index.html
+++ b/documentation/tdenginedocs-en/connector/index.html
@ -72,9 +72,9 @@ The API is used to start a subscription session by given a handle. The parameter
 The API used to get the new data from a TDengine server. It should be put in an infinite loop. The parameter <em>tsub</em> is the handle returned by <em>taos_subscribe</em>. If new data are updated, the API will return a row of the result. Otherwise, the API is blocked until new data arrives. If <em>NULL</em> pointer is returned, it means an error occurs.</p></li>
 <li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code>
 Stop a subscription session by the handle returned by <em>taos_subscribe</em>.</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code>
 The API used to get the number of fields in a row.</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_RES *res)</code>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_RES *res)</code>
 The API used to get the description of each column.</p></li>
 </ul>
 <a class='anchor' id='Java-Connector'></a><h2>Java Connector</h2>
@ -351,4 +351,4 @@ promise2.then(function(result) {
 })</code></pre>
 <h3>Example</h3>
 <p>An example of using the NodeJS connector to create a table with weather data and create and execute queries can be found <a href="https://github.com/taosdata/TDengine/tree/master/tests/examples/nodejs/node-example.js">here</a> (The preferred method for using the connector)</p>
-<p>An example of using the NodeJS connector to achieve the same things but without all the object wrappers that wrap around the data returned to achieve higher functionality can be found <a href="https://github.com/taosdata/TDengine/tree/master/tests/examples/nodejs/node-example-raw.js">here</a></p><a href='../index.html'>Back</a></section></main></div><?php include($s.'/footer.php'); ?><script>$('pre').addClass('prettyprint linenums');PR.prettyPrint()</script><script src='lib/docs/liner.js'></script></body></html>
+<p>An example of using the NodeJS connector to achieve the same things but without all the object wrappers that wrap around the data returned to achieve higher functionality can be found <a href="https://github.com/taosdata/TDengine/tree/master/tests/examples/nodejs/node-example-raw.js">here</a></p><a href='../index.html'>Back</a></section></main></div><?php include($s.'/footer.php'); ?><script>$('pre').addClass('prettyprint linenums');PR.prettyPrint()</script><script src='lib/docs/liner.js'></script></body></html>
--- a/documentation20/webdocs/markdowndocs/architecture-ch.md
+++ b/documentation20/webdocs/markdowndocs/architecture-ch.md
@ -228,7 +228,7 @@ TDengine采用数据驱动的方式让缓存中的数据写入硬盘进行持久

 为充分利用时序数据特点，TDengine将一个vnode保存在持久化存储的数据切分成多个文件，每个文件只保存固定天数的数据，这个天数由系统配置参数days决定。切分成多个文件后，给定查询的起止日期，无需任何索引，就可以立即定位需要打开哪些数据文件，大大加快读取速度。

-对于采集的数据，一般有保留时长，这个时长由系统配置参数keep决定。超过这个设置天数的数据文件，将被系统将自动删除，释放存储空间。
+对于采集的数据，一般有保留时长，这个时长由系统配置参数keep决定。超过这个设置天数的数据文件，将被系统自动删除，释放存储空间。

 给定days与keep两个参数，一个vnode总的数据文件数为：keep/days。总的数据文件个数不宜过大，也不宜过小。10到100以内合适。基于这个原则，可以设置合理的days。 目前的版本，参数keep可以修改，但对于参数days，一但设置后，不可修改。

--- a/documentation20/webdocs/markdowndocs/taosd-ch.md
+++ b/documentation20/webdocs/markdowndocs/taosd-ch.md
@ -61,7 +61,7 @@ vnode与其子模块是通过API直接调用，而不是通过消息队列传递

 mnode是整个系统的大脑，负责整个系统的资源调度，负责meta data的管理与存储。

-一个运行的系统里，只有一个mnode，但它有多个副本（由系统配置参数numOfMpeers控制）。这些副本分布在不同的dnode里，目的是保证系统的高可靠运行。副本之间的数据复制是采用同步而非异步的方式，以确保数据的一致性，确保数据不会丢失。这些副本会自动选举一个Master，其他副本是slave。所有数据更新类的操作，都只能在master上进行，而查询类的可以在slave节点上进行。代码实现上，同步模块与vnode共享，但mnode被分配一个特殊的vgroup ID: 1，而且quorum大于1。整个集群系统是由多个dnode组成的，运行的mnode的副本数不可能超过dnode的个数，但不会超过配置的副本数。如果某个mnode副本宕机一段时间，只要超过半数的mnode副本仍在运行，运行的mnode会自动根据整个系统的资源情况，在其他dnode里再启动一个mnode, 以保证运行的副本数。
+一个运行的系统里，只有一个mnode，但它有多个副本（由系统配置参数numOfMnodes控制）。这些副本分布在不同的dnode里，目的是保证系统的高可靠运行。副本之间的数据复制是采用同步而非异步的方式，以确保数据的一致性，确保数据不会丢失。这些副本会自动选举一个Master，其他副本是slave。所有数据更新类的操作，都只能在master上进行，而查询类的可以在slave节点上进行。代码实现上，同步模块与vnode共享，但mnode被分配一个特殊的vgroup ID: 1，而且quorum大于1。整个集群系统是由多个dnode组成的，运行的mnode的副本数不可能超过dnode的个数，但不会超过配置的副本数。如果某个mnode副本宕机一段时间，只要超过半数的mnode副本仍在运行，运行的mnode会自动根据整个系统的资源情况，在其他dnode里再启动一个mnode, 以保证运行的副本数。

 各个dnode通过信息交换，保存有mnode各个副本的End Point列表，并向其中的master节点定时（间隔由系统配置参数statusInterval控制）发送status消息，消息体里包含该dnode的CPU、内存、剩余存储空间、vnode个数，以及各个vnode的状态(存储空间、原始数据大小、记录条数、角色等）。这样mnode就了解整个系统的资源情况，如果用户创建新的表，就可以决定需要在哪个dnode创建；如果增加或删除dnode, 或者监测到某dnode数据过热、或离线太长，就可以决定需要挪动那些vnode，以实现负载均衡。

--- a/packaging/tools/makeclient_power.sh
+++ b/packaging/tools/makeclient_power.sh
@ -123,7 +123,7 @@ if [[ "$pagMode" != "lite" ]] && [[ "$cpuType" != "aarch32" ]]; then
  cp -r ${examples_dir}/R      ${install_dir}/examples
  sed -i '/password/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/R/command.txt
  cp -r ${examples_dir}/go     ${install_dir}/examples  
-  sed -i '/root/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/go/src/taosapp/taosapp.go
+  sed -i '/root/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/go/taosdemo.go
 fi
 # Copy driver
 mkdir -p ${install_dir}/driver 
--- a/packaging/tools/makepkg_power.sh
+++ b/packaging/tools/makepkg_power.sh
@ -146,7 +146,7 @@ if [[ "$pagMode" != "lite" ]] && [[ "$cpuType" != "aarch32" ]]; then
  cp -r ${examples_dir}/R      ${install_dir}/examples
  sed -i '/password/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/R/command.txt  
  cp -r ${examples_dir}/go     ${install_dir}/examples  
-  sed -i '/root/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/go/src/taosapp/taosapp.go
+  sed -i '/root/ {s/taosdata/powerdb/g}'  ${install_dir}/examples/go/taosdemo.go
 fi
 # Copy driver
 mkdir -p ${install_dir}/driver 
--- a/packaging/tools/post.sh
+++ b/packaging/tools/post.sh
@ -10,6 +10,7 @@ data_dir="/var/lib/taos"
 log_dir="/var/log/taos"
 data_link_dir="/usr/local/taos/data"
 log_link_dir="/usr/local/taos/log"
+install_main_dir="/usr/local/taos"

 # static directory
 cfg_dir="/usr/local/taos/cfg"
@ -134,6 +135,29 @@ function install_config() {
        else
            break
        fi
+    done		
+
+    # user email 
+    #EMAIL_PATTERN='^[A-Za-z0-9\u4e00-\u9fa5]+@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)+$'
+    #EMAIL_PATTERN='^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$'
+    #EMAIL_PATTERN="^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$"
+    echo
+    echo -e -n "${GREEN}Enter your email address for priority support or enter empty to skip${NC}: "
+    read emailAddr
+    while true; do
+        if [ ! -z "$emailAddr" ]; then
+            # check the format of the emailAddr
+            #if [[ "$emailAddr" =~ $EMAIL_PATTERN ]]; then
+                # Write the email address to temp file                    
+                email_file="${install_main_dir}/email" 
+                ${csudo} bash -c "echo $emailAddr > ${email_file}"
+                break         
+            #else
+            #    read -p "Please enter the correct email address: " emailAddr   
+            #fi
+        else
+            break
+        fi
    done	
 }

--- a/src/client/inc/tscSubquery.h
+++ b/src/client/inc/tscSubquery.h
@ -39,7 +39,7 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql);
 int32_t tscHandleInsertRetry(SSqlObj* pSql);

 void tscBuildResFromSubqueries(SSqlObj *pSql);
-void **doSetResultRowData(SSqlObj *pSql, bool finalResult);
+TAOS_ROW doSetResultRowData(SSqlObj *pSql, bool finalResult);

 #ifdef __cplusplus
 }
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@ -309,7 +309,7 @@ typedef struct {
  int32_t               numOfGroups;
  SResRec *             pGroupRec;
  char *                data;
-  void **               tsrow;
+  TAOS_ROW              tsrow;
  int32_t*              length;  // length for each field for current row
  char **               buffer;  // Buffer used to put multibytes encoded using unicode (wchar_t)
  SColumnIndex *        pColumnIndex;
@ -450,9 +450,8 @@ void tscCloseTscObj(STscObj *pObj);

 // todo move to taos? or create a new file: taos_internal.h
 TAOS *taos_connect_a(char *ip, char *user, char *pass, char *db, uint16_t port, void (*fp)(void *, TAOS_RES *, int),
-                     void *param, void **taos);
+                     void *param, TAOS **taos);
 TAOS_RES* taos_query_h(TAOS* taos, const char *sqlstr, TAOS_RES** res);
-
 void waitForQueryRsp(void *param, TAOS_RES *tres, int code);

 void doAsyncQuery(STscObj *pObj, SSqlObj *pSql, __async_cb_func_t fp, void *param, const char *sqlstr, size_t sqlLen);
@ -483,11 +482,11 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
    if (type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BINARY) {
      pData = pInfo->pSqlExpr->param[1].pz;
      pRes->length[columnIndex] = pInfo->pSqlExpr->param[1].nLen;
-      pRes->tsrow[columnIndex] = (pInfo->pSqlExpr->param[1].nType == TSDB_DATA_TYPE_NULL) ? NULL : pData;
+      pRes->tsrow[columnIndex] = (pInfo->pSqlExpr->param[1].nType == TSDB_DATA_TYPE_NULL) ? NULL : (unsigned char*)pData;
    } else {
      assert(bytes == tDataTypeDesc[type].nSize);

-      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : &pInfo->pSqlExpr->param[1].i64Key;
+      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : (unsigned char*)&pInfo->pSqlExpr->param[1].i64Key;
      pRes->length[columnIndex] = bytes;
    }
  } else {
@ -495,7 +494,7 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
      int32_t realLen = varDataLen(pData);
      assert(realLen <= bytes - VARSTR_HEADER_SIZE);

-      pRes->tsrow[columnIndex] = (isNull(pData, type)) ? NULL : ((tstr *)pData)->data;
+      pRes->tsrow[columnIndex] = (isNull(pData, type)) ? NULL : (unsigned char*)((tstr *)pData)->data;
      if (realLen < pInfo->pSqlExpr->resBytes - VARSTR_HEADER_SIZE) {  // todo refactor
        *(pData + realLen + VARSTR_HEADER_SIZE) = 0;
      }
@ -504,7 +503,7 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
    } else {
      assert(bytes == tDataTypeDesc[type].nSize);

-      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : pData;
+      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : (unsigned char*)pData;
      pRes->length[columnIndex] = bytes;
    }
  }
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@ -296,7 +296,7 @@ static int32_t tscProcessDescribeTable(SSqlObj *pSql) {
  return tscSetValueToResObj(pSql, rowLen);
 }
 static int32_t tscGetNthFieldResult(TAOS_ROW row, TAOS_FIELD* fields, int *lengths, int idx, char *result) {
-  const char *val = row[idx];
+  const char *val = (const char*)row[idx];
  if (val == NULL) {
    sprintf(result, "%s", TSDB_DATA_NULL_STR);
    return -1;
--- a/src/client/src/tscProfile.c
+++ b/src/client/src/tscProfile.c
@ -20,8 +20,10 @@
 #include "tutil.h"
 #include "taosmsg.h"

+#include "taos.h"
+
 void  tscSaveSlowQueryFp(void *handle, void *tmrId);
-void *tscSlowQueryConn = NULL;
+TAOS *tscSlowQueryConn = NULL;
 bool  tscSlowQueryConnInitialized = false;

 void tscInitConnCb(void *param, TAOS_RES *result, int code) {
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@ -1380,7 +1380,7 @@ static int tscSetResultPointer(SQueryInfo *pQueryInfo, SSqlRes *pRes) {

  for (int i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
    int16_t offset = tscFieldInfoGetOffset(pQueryInfo, i);
-    pRes->tsrow[i] = ((char*) pRes->data + offset * pRes->numOfRows);
+    pRes->tsrow[i] = (unsigned char*)((char*) pRes->data + offset * pRes->numOfRows);
  }

  return 0;
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@ -51,8 +51,8 @@ static bool validPassword(const char* passwd) {
  return validImpl(passwd, TSDB_PASSWORD_LEN - 1);
 }

-SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pass, const char *auth, const char *db,
-                         uint16_t port, void (*fp)(void *, TAOS_RES *, int), void *param, void **taos) {
+static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pass, const char *auth, const char *db,
+                         uint16_t port, void (*fp)(void *, TAOS_RES *, int), void *param, TAOS **taos) {
  taos_init();

  if (!validUserName(user)) {
@ -243,16 +243,19 @@ static void asyncConnCallback(void *param, TAOS_RES *tres, int code) {
 }

 TAOS *taos_connect_a(char *ip, char *user, char *pass, char *db, uint16_t port, void (*fp)(void *, TAOS_RES *, int),
-                     void *param, void **taos) {
-  SSqlObj* pSql = taosConnectImpl(ip, user, pass, NULL, db, port, asyncConnCallback, param, taos);
+                     void *param, TAOS **taos) {
+  STscObj *pObj = NULL;
+  SSqlObj *pSql = taosConnectImpl(ip, user, pass, NULL, db, port, asyncConnCallback, param, (void **)&pObj);
  if (pSql == NULL) {
    return NULL;
  }
-  
+
+  if (taos) *taos = pObj;
+
  pSql->fetchFp = fp;
  pSql->res.code = tscProcessSql(pSql);
  tscDebug("%p DB async connection is opening", taos);
-  return taos;
+  return pObj;
 }

 void taos_close(TAOS *taos) {
@ -897,7 +900,7 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
  if (pSql->sqlstr == NULL) {
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
    tscError("%p failed to malloc sql string buffer", pSql);
-    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, pRes->code, taos_errstr(taos), pObj);
+    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, pRes->code, taos_errstr(pSql), pObj);
    taosTFree(pSql);
    return pRes->code;
  }
@ -922,7 +925,7 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
  }

  if (code != TSDB_CODE_SUCCESS) {
-    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, code, taos_errstr(taos), pObj);
+    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, code, taos_errstr(pSql), pObj);
  }

  taos_free_result(pSql);
@ -1066,7 +1069,7 @@ int taos_load_table_info(TAOS *taos, const char *tableNameList) {

  tscDoQuery(pSql);

-  tscDebug("%p load multi table meta result:%d %s pObj:%p", pSql, pRes->code, taos_errstr(taos), pObj);
+  tscDebug("%p load multi table meta result:%d %s pObj:%p", pSql, pRes->code, taos_errstr(pSql), pObj);
  if ((code = pRes->code) != TSDB_CODE_SUCCESS) {
    tscFreeSqlObj(pSql);
  }
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@ -2260,7 +2260,7 @@ static void transferNcharData(SSqlObj *pSql, int32_t columnIndex, TAOS_FIELD *pF
    
    int32_t length = taosUcs4ToMbs(pRes->tsrow[columnIndex], pRes->length[columnIndex], pRes->buffer[columnIndex]);
    if ( length >= 0 ) {
-      pRes->tsrow[columnIndex] = pRes->buffer[columnIndex];
+      pRes->tsrow[columnIndex] = (unsigned char*)pRes->buffer[columnIndex];
      pRes->length[columnIndex] = length;
    } else {
      tscError("%p charset:%s to %s. val:%s convert failed.", pSql, DEFAULT_UNICODE_ENCODEC, tsCharset, (char*)pRes->tsrow[columnIndex]);
@ -2288,7 +2288,7 @@ static char *getArithemicInputSrc(void *param, const char *name, int32_t colId)
  return pSupport->data[index] + pSupport->offset * pExpr->resBytes;
 }

-void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {
+TAOS_ROW doSetResultRowData(SSqlObj *pSql, bool finalResult) {
  SSqlCmd *pCmd = &pSql->cmd;
  SSqlRes *pRes = &pSql->res;

@ -2341,7 +2341,7 @@ void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {

      tExprTreeCalcTraverse(pRes->pArithSup->pArithExpr->pExpr, 1, pRes->buffer[i], pRes->pArithSup,
          TSDB_ORDER_ASC, getArithemicInputSrc);
-      pRes->tsrow[i] = pRes->buffer[i];
+      pRes->tsrow[i] = (unsigned char*)pRes->buffer[i];
    }
  }

--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@ -704,16 +704,14 @@ static int32_t getRowExpandSize(STableMeta* pTableMeta) {
 int32_t tscMergeTableDataBlocks(SSqlObj* pSql, SArray* pTableDataBlockList) {
  SSqlCmd* pCmd = &pSql->cmd;

-  // the maximum expanded size in byte when a row-wise data is converted to SDataRow format
-  STableDataBlocks* pOneTableBlock = taosArrayGetP(pTableDataBlockList, 0);
-  int32_t expandSize = getRowExpandSize(pOneTableBlock->pTableMeta);
-
  void* pVnodeDataBlockHashList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
  SArray* pVnodeDataBlockList = taosArrayInit(8, POINTER_BYTES);

  size_t total = taosArrayGetSize(pTableDataBlockList);
  for (int32_t i = 0; i < total; ++i) {
-    pOneTableBlock = taosArrayGetP(pTableDataBlockList, i);
+    // the maximum expanded size in byte when a row-wise data is converted to SDataRow format
+    STableDataBlocks* pOneTableBlock = taosArrayGetP(pTableDataBlockList, i);
+    int32_t expandSize = getRowExpandSize(pOneTableBlock->pTableMeta);
    STableDataBlocks* dataBuf = NULL;
    
    int32_t ret =
--- a/src/connector/go
+++ b/src/connector/go
@ -1 +1 @@
-Subproject commit 8c58c512b6acda8bcdfa48fdc7140227b5221766
+Subproject commit 8d7bf743852897110cbdcc7c4322cd7a74d4167b
--- a/src/dnode/src/dnodeModule.c
+++ b/src/dnode/src/dnodeModule.c
@ -97,7 +97,7 @@ void dnodeCleanupModules() {
    }
  }

-  if (tsModule[TSDB_MOD_MNODE].enable && tsModule[TSDB_MOD_MNODE].cleanUpFp) {
+  if (tsModule[TSDB_MOD_MNODE].cleanUpFp) {
    (*tsModule[TSDB_MOD_MNODE].cleanUpFp)();
  }
 }
--- a/src/dnode/src/dnodeVWrite.c
+++ b/src/dnode/src/dnodeVWrite.c
@ -190,6 +190,7 @@ void dnodeFreeVnodeWqueue(void *wqueue) {

 void dnodeSendRpcVnodeWriteRsp(void *pVnode, void *param, int32_t code) {
  SWriteMsg *pWrite = (SWriteMsg *)param;
+  if (pWrite == NULL) return;

  if (code < 0) pWrite->code = code;
  int32_t count = atomic_add_fetch_32(&pWrite->processedCount, 1);
--- a/src/inc/taos.h
+++ b/src/inc/taos.h
@ -22,12 +22,12 @@
 extern "C" {
 #endif

-typedef void    TAOS;
-typedef void**  TAOS_ROW;
-typedef void    TAOS_RES;
-typedef void    TAOS_SUB;
-typedef void    TAOS_STREAM;
-typedef void    TAOS_STMT;
+typedef void   TAOS;
+typedef void   TAOS_STMT;
+typedef void   TAOS_RES;
+typedef void   TAOS_STREAM;
+typedef void   TAOS_SUB;
+typedef void **TAOS_ROW;

 // Data type definition
 #define TSDB_DATA_TYPE_NULL       0     // 1 bytes
--- a/src/inc/vnode.h
+++ b/src/inc/vnode.h
@ -56,6 +56,7 @@ void    vnodeRelease(void *pVnode);        // dec refCount
 void*   vnodeGetWal(void *pVnode);

 int32_t vnodeProcessWrite(void *pVnode, int qtype, void *pHead, void *item);
+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);
@ -65,6 +66,7 @@ int32_t vnodeInitResources();
 void    vnodeCleanupResources();

 int32_t vnodeProcessRead(void *pVnode, SReadMsg *pReadMsg);
+int32_t vnodeCheckRead(void *pVnode);

 #ifdef __cplusplus
 }
--- a/src/kit/shell/inc/shell.h
+++ b/src/kit/shell/inc/shell.h
@ -60,7 +60,7 @@ typedef struct SShellArguments {
 extern void shellParseArgument(int argc, char* argv[], SShellArguments* arguments);
 extern TAOS* shellInit(SShellArguments* args);
 extern void* shellLoopQuery(void* arg);
-extern void taos_error(TAOS* con);
+extern void taos_error(TAOS_RES* tres);
 extern int regex_match(const char* s, const char* reg, int cflags);
 void shellReadCommand(TAOS* con, char command[]);
 int32_t shellRunCommand(TAOS* con, char* command);
@ -72,7 +72,7 @@ void source_dir(TAOS* con, SShellArguments* args);
 void get_history_path(char* history);
 void cleanup_handler(void* arg);
 void exitShell();
-int shellDumpResult(TAOS* con, char* fname, int* error_no, bool printMode);
+int shellDumpResult(TAOS_RES* con, char* fname, int* error_no, bool printMode);
 void shellGetGrantInfo(void *con);
 int isCommentLine(char *line);

--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@ -493,7 +493,7 @@ static int dumpResultToFile(const char* fname, TAOS_RES* tres) {
      if (i > 0) {
        fputc(',', fp);
      }
-      dumpFieldToFile(fp, row[i], fields +i, length[i], precision);
+      dumpFieldToFile(fp, (const char*)row[i], fields +i, length[i], precision);
    }
    fputc('\n', fp);

@ -619,7 +619,7 @@ static int verticalPrintResult(TAOS_RES* tres) {
      int padding = (int)(maxColNameLen - strlen(field->name));
      printf("%*.s%s: ", padding, " ", field->name);

-      printField(row[i], field, 0, length[i], precision);
+      printField((const char*)row[i], field, 0, length[i], precision);
      putchar('\n');
    }

@ -720,7 +720,7 @@ static int horizontalPrintResult(TAOS_RES* tres) {
    int32_t* length = taos_fetch_lengths(tres);
    for (int i = 0; i < num_fields; i++) {
      putchar(' ');
-      printField(row[i], fields + i, width[i], length[i], precision);
+      printField((const char*)row[i], fields + i, width[i], length[i], precision);
      putchar(' ');
      putchar('|');
    }
--- a/src/kit/shell/src/shellImport.c
+++ b/src/kit/shell/src/shellImport.c
@ -204,7 +204,7 @@ static void shellSourceFile(TAOS *con, char *fptr) {
    int32_t code = taos_errno(pSql);
    
    if (code != 0) {
-      fprintf(stderr, "DB error: %s: %s (%d)\n", taos_errstr(con), fname, lineNo);
+      fprintf(stderr, "DB error: %s: %s (%d)\n", taos_errstr(pSql), fname, lineNo);
    }
    
    /* free local resouce: allocated memory/metric-meta refcnt */
@ -243,7 +243,7 @@ static void shellRunImportThreads(SShellArguments* args)
    pThread->totalThreads = args->threadNum;
    pThread->taos = taos_connect(args->host, args->user, args->password, args->database, tsDnodeShellPort);
    if (pThread->taos == NULL) {
-      fprintf(stderr, "ERROR: thread:%d failed connect to TDengine, error:%s\n", pThread->threadIndex, taos_errstr(pThread->taos));
+      fprintf(stderr, "ERROR: thread:%d failed connect to TDengine, error:%s\n", pThread->threadIndex, "null taos"/*taos_errstr(pThread->taos)*/);
      exit(0);
    }

--- a/src/kit/shell/src/shellWindows.c
+++ b/src/kit/shell/src/shellWindows.c
@ -90,11 +90,12 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
      }
    } else if (strcmp(argv[i], "-c") == 0) {
      if (i < argc - 1) {   
-        if (strlen(argv[++i]) >= TSDB_FILENAME_LEN) {
-          fprintf(stderr, "config file path: %s overflow max len %d\n", argv[i], TSDB_FILENAME_LEN - 1);
+        char *tmp = argv[++i];
+        if (strlen(tmp) >= TSDB_FILENAME_LEN) {
+          fprintf(stderr, "config file path: %s overflow max len %d\n", tmp, TSDB_FILENAME_LEN - 1);
          exit(EXIT_FAILURE);
        }
-        strcpy(configDir, argv[++i]);
+        strcpy(configDir, tmp);
      } else {
        fprintf(stderr, "Option -c requires an argument\n");
        exit(EXIT_FAILURE);
--- a/src/mnode/src/mnodeMain.c
+++ b/src/mnode/src/mnodeMain.c
@ -123,16 +123,18 @@ int32_t mnodeInitSystem() {
 }

 void mnodeCleanupSystem() {
-  mInfo("starting to clean up mnode");
-  tsMgmtIsRunning = false;
+  if (tsMgmtIsRunning) {
+    mInfo("starting to clean up mnode");
+    tsMgmtIsRunning = false;

-  dnodeFreeMnodeWqueue();
-  dnodeFreeMnodeRqueue();
-  dnodeFreeMnodePqueue();
-  mnodeCleanupTimer();
-  mnodeCleanupComponents(sizeof(tsMnodeComponents) / sizeof(tsMnodeComponents[0]) - 1);
-  
-  mInfo("mnode is cleaned up");
+    dnodeFreeMnodeWqueue();
+    dnodeFreeMnodeRqueue();
+    dnodeFreeMnodePqueue();
+    mnodeCleanupTimer();
+    mnodeCleanupComponents(sizeof(tsMnodeComponents) / sizeof(tsMnodeComponents[0]) - 1);
+
+    mInfo("mnode is cleaned up");
+  }
 }

 void mnodeStopSystem() {
--- a/src/plugins/http/inc/httpInt.h
+++ b/src/plugins/http/inc/httpInt.h
@ -122,9 +122,9 @@ typedef struct {
 } HttpDecodeMethod;

 typedef struct {
-  void (*startJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd, void *result);
+  void (*startJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result);
  void (*stopJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd);
-  bool (*buildQueryJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd, void *result, int numOfRows);
+  bool (*buildQueryJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result, int numOfRows);
  void (*buildAffectRowJsonFp)(struct HttpContext *pContext, HttpSqlCmd *cmd, int affectRows);
  void (*initJsonFp)(struct HttpContext *pContext);
  void (*cleanJsonFp)(struct HttpContext *pContext);
@ -148,7 +148,7 @@ typedef struct HttpContext {
  char         ipstr[22];
  char         user[TSDB_USER_LEN];  // parsed from auth token or login message
  char         pass[TSDB_PASSWORD_LEN];
-  void *       taos;
+  TAOS *       taos;
  void *       ppContext;
  HttpSession *session;
  z_stream     gzipStream;
--- a/src/plugins/http/src/httpGcJson.c
+++ b/src/plugins/http/src/httpGcJson.c
@ -217,7 +217,7 @@ bool gcBuildQueryJson(HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result,
          break;
        case TSDB_DATA_TYPE_BINARY:
        case TSDB_DATA_TYPE_NCHAR:
-          httpJsonStringForTransMean(jsonBuf, row[i], fields[i].bytes);
+          httpJsonStringForTransMean(jsonBuf, (char*)row[i], fields[i].bytes);
          break;
        case TSDB_DATA_TYPE_TIMESTAMP:
          if (precision == TSDB_TIME_PRECISION_MILLI) { //ms
--- a/src/plugins/http/src/httpRestJson.c
+++ b/src/plugins/http/src/httpRestJson.c
@ -131,7 +131,7 @@ bool restBuildSqlJson(HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result,
          break;
        case TSDB_DATA_TYPE_BINARY:
        case TSDB_DATA_TYPE_NCHAR:
-          httpJsonStringForTransMean(jsonBuf, row[i], length[i]);
+          httpJsonStringForTransMean(jsonBuf, (char*)row[i], length[i]);
          break;
        case TSDB_DATA_TYPE_TIMESTAMP:
          if (timestampFormat == REST_TIMESTAMP_FMT_LOCAL_STRING) {
@ -195,4 +195,4 @@ void restStopSqlJson(HttpContext *pContext, HttpSqlCmd *cmd) {
  httpJsonToken(jsonBuf, JsonObjEnd);

  httpWriteJsonBufEnd(jsonBuf);
-}
+}
--- a/src/plugins/http/src/httpSql.c
+++ b/src/plugins/http/src/httpSql.c
@ -27,8 +27,6 @@
 #include "httpSession.h"
 #include "httpQueue.h"

-void *taos_connect_a(char *ip, char *user, char *pass, char *db, uint16_t port, void (*fp)(void *, TAOS_RES *, int),
-                     void *param, void **taos);
 void httpProcessMultiSql(HttpContext *pContext);

 void httpProcessMultiSqlRetrieveCallBack(void *param, TAOS_RES *result, int numOfRows);
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@ -6870,7 +6870,7 @@ int32_t qRetrieveQueryResultInfo(qinfo_t qinfo, bool* buildRes, void* pRspContex

  *buildRes = false;
  if (IS_QUERY_KILLED(pQInfo)) {
-    qDebug("QInfo:%p query is killed, code:%d", pQInfo, pQInfo->code);
+    qDebug("QInfo:%p query is killed, code:0x%08x", pQInfo, pQInfo->code);
    return pQInfo->code;
  }

@ -7290,13 +7290,20 @@ void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
 void** qAcquireQInfo(void* pMgmt, uint64_t _key) {
  SQueryMgmt *pQueryMgmt = pMgmt;

-  if (pQueryMgmt->qinfoPool == NULL || pQueryMgmt->closed) {
+  if (pQueryMgmt->closed) {
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
+    return NULL;
+  }
+
+  if (pQueryMgmt->qinfoPool == NULL) {
+    terrno = TSDB_CODE_QRY_INVALID_QHANDLE;
    return NULL;
  }

  TSDB_CACHE_PTR_TYPE key = (TSDB_CACHE_PTR_TYPE)_key;
  void** handle = taosCacheAcquireByKey(pQueryMgmt->qinfoPool, &key, sizeof(TSDB_CACHE_PTR_TYPE));
  if (handle == NULL || *handle == NULL) {
+    terrno = TSDB_CODE_QRY_INVALID_QHANDLE;
    return NULL;
  } else {
    return handle;
--- a/src/query/src/qExtbuffer.c
+++ b/src/query/src/qExtbuffer.c
@ -344,8 +344,6 @@ static FORCE_INLINE int32_t primaryKeyComparator(int64_t f1, int64_t f2, int32_t
    return 0;
  }

-  assert(colIdx == 0);
-
  if (tsOrder == TSDB_ORDER_DESC) {  // primary column desc order
    return (f1 < f2) ? 1 : -1;
  } else {  // asc
--- a/src/rpc/src/rpcTcp.c
+++ b/src/rpc/src/rpcTcp.c
@ -174,12 +174,15 @@ static void taosStopTcpThread(SThreadObj* pThreadObj) {
  pThreadObj->stop = true;
  eventfd_t fd = -1;

+  // save thread into local variable since pThreadObj is freed when thread exits
+  pthread_t thread = pThreadObj->thread; 
+
  if (taosComparePthread(pThreadObj->thread, pthread_self())) {
    pthread_detach(pthread_self());
    return;
  }

-  if (taosCheckPthreadValid(pThreadObj->thread) && pThreadObj->pollFd >= 0) {
+  if (taosCheckPthreadValid(pThreadObj->thread)) {
    // signal the thread to stop, try graceful method first,
    // and use pthread_cancel when failed
    struct epoll_event event = { .events = EPOLLIN };
@ -196,8 +199,9 @@ static void taosStopTcpThread(SThreadObj* pThreadObj) {
    }
  }

-  if (taosCheckPthreadValid(pThreadObj->thread) && pThreadObj->pollFd >= 0) {
-     pthread_join(pThreadObj->thread, NULL);
+  // at this step, pThreadObj has already been released
+  if (taosCheckPthreadValid(thread)) {
+     pthread_join(thread, NULL);
  }

  if (fd != -1) taosCloseSocket(fd);
--- a/src/sync/CMakeLists.txt
+++ b/src/sync/CMakeLists.txt
@ -5,14 +5,14 @@ INCLUDE_DIRECTORIES(inc)
 AUX_SOURCE_DIRECTORY(src SRC)
  
 IF (TD_LINUX)
-  LIST(REMOVE_ITEM SRC ./src/tarbitrator.c)
+  LIST(REMOVE_ITEM SRC src/tarbitrator.c)
  ADD_LIBRARY(sync ${SRC})
  TARGET_LINK_LIBRARIES(sync tutil pthread common)

-  LIST(APPEND BIN_SRC ./src/tarbitrator.c)
-  LIST(APPEND BIN_SRC ./src/taosTcpPool.c)
+  LIST(APPEND BIN_SRC src/tarbitrator.c)
+  LIST(APPEND BIN_SRC src/taosTcpPool.c)
  ADD_EXECUTABLE(tarbitrator ${BIN_SRC})
  TARGET_LINK_LIBRARIES(tarbitrator sync common osdetail tutil)

-  ADD_SUBDIRECTORY(test)
+  #ADD_SUBDIRECTORY(test)
 ENDIF ()
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@ -465,9 +465,10 @@ void *vnodeAcquireRqueue(int32_t vgId) {
  SVnodeObj *pVnode = vnodeAcquire(vgId);
  if (pVnode == NULL) return NULL;

-  if (pVnode->status == TAOS_VN_STATUS_RESET) {           
-    terrno = TSDB_CODE_APP_NOT_READY;
-    vInfo("vgId:%d, status is in reset", vgId);
+  int32_t code = vnodeCheckRead(pVnode);
+  if (code != TSDB_CODE_SUCCESS) {
+    terrno = code;
+    vInfo("vgId:%d, can not provide read service, status is %s", vgId, vnodeStatus[pVnode->status]);
    vnodeRelease(pVnode);
    return NULL;
  }
@ -479,13 +480,14 @@ void *vnodeAcquireWqueue(int32_t vgId) {
  SVnodeObj *pVnode = vnodeAcquire(vgId);
  if (pVnode == NULL) return NULL;

-  if (pVnode->status == TAOS_VN_STATUS_RESET) {           
-    terrno = TSDB_CODE_APP_NOT_READY;
-    vInfo("vgId:%d, status is in reset", vgId);
+  int32_t code = vnodeCheckWrite(pVnode);
+  if (code != TSDB_CODE_SUCCESS) {
+    terrno = code;
+    vInfo("vgId:%d, can not provide write service, status is %s", vgId, vnodeStatus[pVnode->status]);
    vnodeRelease(pVnode);
    return NULL;
  }
-  
+
  return pVnode->wqueue;
 }

--- a/src/vnode/src/vnodeRead.c
+++ b/src/vnode/src/vnodeRead.c
@ -39,7 +39,13 @@ void vnodeInitReadFp(void) {
  vnodeProcessReadMsgFp[TSDB_MSG_TYPE_FETCH] = vnodeProcessFetchMsg;
 }

-static int32_t vnodeProcessReadImp(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
+//
+// After the fetch request enters the vnode queue, if the vnode cannot provide services, the process function are
+// still required, or there will be a deadlock, so we don’t do any check here, but put the check codes before the
+// request enters the queue
+//
+int32_t vnodeProcessRead(void *param, SReadMsg *pReadMsg) {
+  SVnodeObj *pVnode = (SVnodeObj *)param;
  int msgType = pReadMsg->rpcMsg.msgType;

  if (vnodeProcessReadMsgFp[msgType] == NULL) {
@ -47,53 +53,35 @@ static int32_t vnodeProcessReadImp(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
    return TSDB_CODE_VND_MSG_NOT_PROCESSED;
  }

+  return (*vnodeProcessReadMsgFp[msgType])(pVnode, pReadMsg);
+}
+
+int32_t vnodeCheckRead(void *param) {
+  SVnodeObj *pVnode = param;
  if (pVnode->status != TAOS_VN_STATUS_READY) {
-    vDebug("vgId:%d, msgType:%s not processed, vnode status is %s", pVnode->vgId, taosMsg[msgType],
-           vnodeStatus[pVnode->status]);
+    vDebug("vgId:%d, vnode status is %s, recCount:%d pVnode:%p", pVnode->vgId, vnodeStatus[pVnode->status],
+           pVnode->refCount, pVnode);
    return TSDB_CODE_APP_NOT_READY;
  }

  // tsdb may be in reset state
  if (pVnode->tsdb == NULL) {
-    vDebug("vgId:%d, msgType:%s not processed, tsdb is null", pVnode->vgId, taosMsg[msgType]);
-    return TSDB_CODE_APP_NOT_READY;
-  }
-
-  if (pVnode->status == TAOS_VN_STATUS_CLOSING) {
-    vDebug("vgId:%d, msgType:%s not processed, vstatus is %s", pVnode->vgId, taosMsg[msgType],
-           vnodeStatus[pVnode->status]);
+    vDebug("vgId:%d, tsdb is null, recCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
    return TSDB_CODE_APP_NOT_READY;
  }

  if (pVnode->role != TAOS_SYNC_ROLE_SLAVE && pVnode->role != TAOS_SYNC_ROLE_MASTER) {
-    vDebug("vgId:%d, msgType:%s not processed, replica:%d role:%s", pVnode->vgId, taosMsg[msgType],
-           pVnode->syncCfg.replica, syncRole[pVnode->role]);
+    vDebug("vgId:%d, replica:%d role:%s, recCount:%d pVnode:%p", pVnode->vgId, pVnode->syncCfg.replica,
+           syncRole[pVnode->role], pVnode->refCount, pVnode);
    return TSDB_CODE_APP_NOT_READY;
  }

-  return (*vnodeProcessReadMsgFp[msgType])(pVnode, pReadMsg);
+  return TSDB_CODE_SUCCESS;
 }
+static int32_t vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void **qhandle, void *ahandle) {
+  int32_t code = vnodeCheckRead(pVnode);
+  if (code != TSDB_CODE_SUCCESS) return code;

-int32_t vnodeProcessRead(void *param, SReadMsg *pRead) {
-  SVnodeObj *pVnode = (SVnodeObj *)param;
-  int32_t    code = vnodeProcessReadImp(pVnode, pRead);
-
-  if (code == TSDB_CODE_APP_NOT_READY && pRead->rpcMsg.msgType == TSDB_MSG_TYPE_QUERY) {
-    // After the fetch request enters the vnode queue
-    // If the vnode cannot provide services, the following operations are still required
-    // Or, there will be a deadlock
-    void **qhandle = (void **)pRead->pCont;
-    vError("QInfo:%p msg:%p will be killed for vstatus is %s", *qhandle, pRead, vnodeStatus[pVnode->status]);
-
-    // qKillQuery(*qhandle);
-    // qReleaseQInfo(pVnode->qMgmt, (void **)&qhandle, true);
-    return TSDB_CODE_APP_NOT_READY;
-  } else {
-    return code;
-  }
-}
-
-static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void **qhandle, void *ahandle) {
  SReadMsg *pRead = (SReadMsg *)taosAllocateQitem(sizeof(SReadMsg));
  pRead->rpcMsg.msgType = TSDB_MSG_TYPE_QUERY;
  pRead->pCont = qhandle;
@ -104,6 +92,8 @@ static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void **qhandle, void *a

  vDebug("QInfo:%p add to vread queue for exec query, msg:%p", *qhandle, pRead);
  taosWriteQitem(pVnode->rqueue, TAOS_QTYPE_QUERY, pRead);
+
+  return TSDB_CODE_SUCCESS;
 }

 /**
@ -122,8 +112,13 @@ static int32_t vnodeDumpQueryResult(SRspRet *pRet, void *pVnode, void **handle,
  if ((code = qDumpRetrieveResult(*handle, (SRetrieveTableRsp **)&pRet->rsp, &pRet->len, &continueExec)) == TSDB_CODE_SUCCESS) {
    if (continueExec) {
      *freeHandle = false;
-      vnodePutItemIntoReadQueue(pVnode, handle, ahandle);
-      pRet->qhandle = *handle;
+      code = vnodePutItemIntoReadQueue(pVnode, handle, ahandle);
+      if (code != TSDB_CODE_SUCCESS) {
+        *freeHandle = true;
+        return code;
+      } else {
+        pRet->qhandle = *handle;
+      }
    } else {
      *freeHandle = true;
      vDebug("QInfo:%p exec completed, free handle:%d", *handle, *freeHandle);
@ -226,7 +221,12 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {

    if (handle != NULL) {
      vDebug("vgId:%d, QInfo:%p, dnode query msg disposed, create qhandle and returns to app", vgId, *handle);
-      vnodePutItemIntoReadQueue(pVnode, handle, pReadMsg->rpcMsg.ahandle);
+      code = vnodePutItemIntoReadQueue(pVnode, handle, pReadMsg->rpcMsg.ahandle);
+      if (code != TSDB_CODE_SUCCESS) {
+        pRsp->code = code;
+        qReleaseQInfo(pVnode->qMgmt, (void **)&handle, true);
+        return pRsp->code;
+      }
    }
  } else {
    assert(pCont != NULL);
@ -287,16 +287,22 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {

  memset(pRet, 0, sizeof(SRspRet));

+  terrno = TSDB_CODE_SUCCESS;
  int32_t code = TSDB_CODE_SUCCESS;
  void ** handle = qAcquireQInfo(pVnode->qMgmt, pRetrieve->qhandle);
-  if (handle == NULL || (*handle) != (void *)pRetrieve->qhandle) {
+  if (handle == NULL) {
+    code = terrno;
+    terrno = TSDB_CODE_SUCCESS;
+  } else if ((*handle) != (void *)pRetrieve->qhandle) {
    code = TSDB_CODE_QRY_INVALID_QHANDLE;
-    vDebug("vgId:%d, invalid qhandle in retrieving result, QInfo:%p", pVnode->vgId, (void *)pRetrieve->qhandle);
+  }

+  if (code != TSDB_CODE_SUCCESS) {
+    vDebug("vgId:%d, invalid handle in retrieving result, code:0x%08x, QInfo:%p", pVnode->vgId, code, (void *)pRetrieve->qhandle);
    vnodeBuildNoResultQueryRsp(pRet);
    return code;
  }
-
+  
  if (pRetrieve->free == 1) {
    vWarn("vgId:%d, QInfo:%p, retrieve msg received to kill query and free qhandle", pVnode->vgId, *handle);
    qKillQuery(*handle);
--- a/src/vnode/src/vnodeWrite.c
+++ b/src/vnode/src/vnodeWrite.c
@ -56,15 +56,6 @@ int32_t vnodeProcessWrite(void *param1, int qtype, void *param2, void *item) {
    return TSDB_CODE_VND_MSG_NOT_PROCESSED;
  }

-  if (!(pVnode->accessState & TSDB_VN_WRITE_ACCCESS)) {
-    vDebug("vgId:%d, msgType:%s not processed, no write auth", pVnode->vgId, taosMsg[pHead->msgType]);
-    return TSDB_CODE_VND_NO_WRITE_AUTH;
-  }
-
-  // tsdb may be in reset state
-  if (pVnode->tsdb == NULL) return TSDB_CODE_APP_NOT_READY;
-  if (pVnode->status == TAOS_VN_STATUS_CLOSING) return TSDB_CODE_APP_NOT_READY;
-
  if (pHead->version == 0) {  // from client or CQ
    if (pVnode->status != TAOS_VN_STATUS_READY) {
      vDebug("vgId:%d, msgType:%s not processed, vnode status is %d", pVnode->vgId, taosMsg[pHead->msgType],
@ -105,6 +96,28 @@ int32_t vnodeProcessWrite(void *param1, int qtype, void *param2, void *item) {
  return syncCode;
 }

+int32_t vnodeCheckWrite(void *param) {
+  SVnodeObj *pVnode = param;
+  if (!(pVnode->accessState & TSDB_VN_WRITE_ACCCESS)) {
+    vDebug("vgId:%d, no write auth, recCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
+    return TSDB_CODE_VND_NO_WRITE_AUTH;
+  }
+
+  // tsdb may be in reset state
+  if (pVnode->tsdb == NULL) {
+    vDebug("vgId:%d, tsdb is null, recCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
+    return TSDB_CODE_APP_NOT_READY;
+  }
+
+  if (pVnode->status == TAOS_VN_STATUS_CLOSING) {
+    vDebug("vgId:%d, vnode status is %s, recCount:%d pVnode:%p", pVnode->vgId, vnodeStatus[pVnode->status],
+           pVnode->refCount, pVnode);
+    return TSDB_CODE_APP_NOT_READY;
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
 void vnodeConfirmForward(void *param, uint64_t version, int32_t code) {
  SVnodeObj *pVnode = (SVnodeObj *)param;
  syncConfirmForward(pVnode->sync, version, code);
--- a/src/wal/src/walMain.c
+++ b/src/wal/src/walMain.c
@ -60,6 +60,7 @@ 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");
@ -312,7 +313,7 @@ int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int))
    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) break;
+      if (terrno < 0) continue;
    }
  }

@ -476,31 +477,26 @@ int walHandleExistingFiles(const char *path) {
  int    plen = strlen(walPrefix);
  terrno = 0;

-  if (access(opath, F_OK) == 0) {
-    // old directory is there, it means restore process is not finished
-    walRemoveWalFiles(path);
-
-  } else {
-    // move all files to old directory
-    int count = 0;
-    while ((ent = readdir(dir)) != NULL) {
-      if (strncmp(ent->d_name, walPrefix, plen) == 0) {
-        snprintf(oname, sizeof(oname), "%s/%s", path, ent->d_name);
-        snprintf(nname, sizeof(nname), "%s/old/%s", path, ent->d_name);
-        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++;
+  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);
@ -563,4 +559,30 @@ int64_t walGetVersion(twalh param) {
  if (pWal == 0) return 0;

  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;
 }
--- a/tests/comparisonTest/tdengine/tdengineTest.c
+++ b/tests/comparisonTest/tdengine/tdengineTest.c
@ -108,9 +108,9 @@ void parseArg(int argc, char *argv[]) {
  }
 }

-void taos_error(TAOS *con) {
-  printf("TDengine error: %s\n", taos_errstr(con));
-  taos_close(con);
+static void taos_error(TAOS_RES *tres, TAOS *conn) {
+  printf("TDengine error: %s\n", tres?taos_errstr(tres):"null result");
+  taos_close(conn);
  exit(1);
 }

@ -125,13 +125,17 @@ void writeDataImp(void *param) {
  printf("Thread %d, writing sID %d, eID %d\n", pThread->threadId, pThread->sID, pThread->eID);

  void *taos = taos_connect("127.0.0.1", "root", "taosdata", NULL, 0);
-  if (taos == NULL)
-    taos_error(taos);
+  if (taos == NULL) {
+    // where to find errstr?
+    // taos_error(NULL, taos);
+    printf("TDengine error: %s\n", "failed to connect");
+    exit(1);
+  }

  TAOS_RES* result = taos_query(taos, "use db");
  int32_t code = taos_errno(result);
  if (code != 0) {
-    taos_error(taos);
+    taos_error(result, taos);
  }
  taos_free_result(result);

@ -227,12 +231,17 @@ void writeData() {
  taos_init();

  void *taos = taos_connect("127.0.0.1", "root", "taosdata", NULL, 0);
-  if (taos == NULL) taos_error(taos);
+  if (taos == NULL) {
+    // where to find errstr?
+    // taos_error(NULL, taos);
+    printf("TDengine error: %s\n", "failed to connect");
+    exit(1);
+  }

  TAOS_RES *result = taos_query(taos, "create database if not exists db");
  int32_t   code = taos_errno(result);
  if (code != 0) {
-    taos_error(taos);
+    taos_error(result, taos);
  }
  taos_free_result(result);

@ -241,7 +250,7 @@ void writeData() {
                      "tags(devid int, devname binary(16), devgroup int)");
  code = taos_errno(result);
  if (code != 0) {
-    taos_error(taos);
+    taos_error(result, taos);
  }
  taos_free_result(result);

@ -293,8 +302,12 @@ void readDataImp(void *param)
  printf("open file %s success\n", arguments.sql);

  void *taos = taos_connect("127.0.0.1", "root", "taosdata", NULL, 0);
-  if (taos == NULL)
-    taos_error(taos);
+  if (taos == NULL) {
+    // where to find errstr?
+    // taos_error(NULL, taos);
+    printf("TDengine error: %s\n", "failed to connect");
+    exit(1);
+  }

  char *line = NULL;
  size_t len = 0;
@ -313,7 +326,7 @@ void readDataImp(void *param)
    TAOS_RES *result = taos_query(taos, line);
    int32_t   code = taos_errno(result);
    if (code != 0) {
-      taos_error(taos);
+      taos_error(result, taos);
    }

    TAOS_ROW row;
@ -343,8 +356,12 @@ void readData() {
  printf("---- clients: %d\n", arguments.clients);

  void *taos = taos_connect("127.0.0.1", "root", "taosdata", NULL, 0);
-  if (taos == NULL)
-    taos_error(taos);
+  if (taos == NULL) {
+    // where to find errstr?
+    // taos_error(NULL, taos);
+    printf("TDengine error: %s\n", "failed to connect");
+    exit(1);
+  }

  ThreadObj *threads = calloc((size_t)arguments.clients, sizeof(ThreadObj));

--- a/tests/examples/c/demo.c
+++ b/tests/examples/c/demo.c
@ -38,7 +38,7 @@ int main(int argc, char *argv[]) {

  taos = taos_connect(argv[1], "root", "taosdata", NULL, 0);
  if (taos == NULL) {
-    printf("failed to connect to server, reason:%s\n", taos_errstr(taos));
+    printf("failed to connect to server, reason:%s\n", "null taos"/*taos_errstr(taos)*/);
    exit(1);
  }
  printf("success to connect to server\n");
@ -48,7 +48,7 @@ int main(int argc, char *argv[]) {

  result = taos_query(taos, "create database demo");
  if (result == NULL) {
-    printf("failed to create database, reason:%s\n", taos_errstr(taos));
+    printf("failed to create database, reason:%s\n", "null result"/*taos_errstr(taos)*/);
    exit(1);
  }
  printf("success to create database\n");
@ -57,7 +57,7 @@ int main(int argc, char *argv[]) {

  // create table
  if (taos_query(taos, "create table m1 (ts timestamp, ti tinyint, si smallint, i int, bi bigint, f float, d double, b binary(10))") == 0) {
-    printf("failed to create table, reason:%s\n", taos_errstr(taos));
+    printf("failed to create table, reason:%s\n", taos_errstr(result));
    exit(1);
  }
  printf("success to create table\n");
@ -70,9 +70,19 @@ int main(int argc, char *argv[]) {
  for (i = 0; i < 10; ++i) {
    sprintf(qstr, "insert into m1 values (%" PRId64 ", %d, %d, %d, %d, %f, %lf, '%s')", 1546300800000 + i * 1000, i, i, i, i*10000000, i*1.0, i*2.0, "hello");
    printf("qstr: %s\n", qstr);
-    if (taos_query(taos, qstr)) {
-      printf("insert row: %i, reason:%s\n", i, taos_errstr(taos));
+    
+    // note: how do you wanna do if taos_query returns non-NULL
+    // if (taos_query(taos, qstr)) {
+    //   printf("insert row: %i, reason:%s\n", i, taos_errstr(taos));
+    // }
+    TAOS_RES *result = taos_query(taos, qstr);
+    if (result) {
+      printf("insert row: %i\n", i);
+    } else {
+      printf("failed to insert row: %i, reason:%s\n", i, "null result"/*taos_errstr(result)*/);
+      exit(1);
    }
+
    //sleep(1);
  }
  printf("success to insert rows, total %d rows\n", i);
--- a/tests/examples/rust/src/bindings.rs
+++ b/tests/examples/rust/src/bindings.rs
@ -308,12 +308,6 @@ extern "C" {
 extern "C" {
    pub fn taos_unsubscribe(tsub: *mut ::std::os::raw::c_void);
 }
-extern "C" {
-    pub fn taos_subfields_count(tsub: *mut ::std::os::raw::c_void) -> ::std::os::raw::c_int;
-}
-extern "C" {
-    pub fn taos_fetch_subfields(tsub: *mut ::std::os::raw::c_void) -> *mut TAOS_FIELD;
-}
 extern "C" {
    pub fn taos_open_stream(
        taos: *mut ::std::os::raw::c_void,
--- a/tests/examples/rust/src/subscriber.rs
+++ b/tests/examples/rust/src/subscriber.rs
@ -37,16 +37,16 @@ impl Subscriber {
            println!("subscribed to {} user:{}, db:{}, tb:{}, time:{}, mseconds:{}",
                        host, username, db, table, time, mseconds);

-            let mut fields = taos_fetch_subfields(tsub);
+            let mut fields = taos_fetch_fields(tsub);
            if fields.is_null() {
                taos_unsubscribe(tsub);
-                return Err("fetch subfields error")
+                return Err("fetch fields error")
            }

-            let fcount = taos_subfields_count(tsub);
+            let fcount = taos_field_count(tsub);
            if fcount == 0 {
                taos_unsubscribe(tsub);
-                return Err("subfields count is 0")
+                return Err("fields count is 0")
            }

            Ok(Subscriber{tsub, fields, fcount})
@ -74,4 +74,4 @@ impl Drop for Subscriber {
    fn drop(&mut self) {
        unsafe {taos_unsubscribe(self.tsub);}
    }
-}
+}
--- a/tests/gotest/batchtest.bat
+++ b/tests/gotest/batchtest.bat
@ -7,6 +7,9 @@ set serverPort=%2
 if "%severIp%"=="" (set severIp=127.0.0.1)
 if "%serverPort%"=="" (set serverPort=6030)

+go env -w GO111MODULE=on
+go env -w GOPROXY=https://goproxy.io,direct
+
 cd case001
 case001.bat %severIp% %serverPort%  

--- a/tests/gotest/batchtest.sh
+++ b/tests/gotest/batchtest.sh
@ -13,6 +13,9 @@ if [ ! -n "$serverPort" ]; then
  serverPort=6030
 fi

+go env -w GO111MODULE=on
+go env -w GOPROXY=https://goproxy.io,direct
+
 bash ./case001/case001.sh $severIp $serverPort
 #bash ./case002/case002.sh $severIp $serverPort
 #bash ./case003/case003.sh $severIp $serverPort
--- a/tests/pytest/cluster/bananceTest.py
+++ b/tests/pytest/cluster/bananceTest.py
@ -0,0 +1,57 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+import time
+
+class ClusterTestcase:
+    
+    ## test case 32 ##
+    def run(self):
+        
+        nodes = Nodes()        
+        nodes.addConfigs("maxVgroupsPerDb", "10")
+        nodes.addConfigs("maxTablesPerVnode", "1000")
+        nodes.restartAllTaosd()
+
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()                
+        ctest.createSTable(1)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        tdSql.execute("use %s" % ctest.dbName) 
+        tdSql.query("show vgroups")
+        dnodes = []
+        for i in range(10):
+            dnodes.append(int(tdSql.getData(i, 4)))
+        
+        s = set(dnodes)
+        if len(s) < 3:
+            tdLog.exit("cluster is not balanced")
+        
+        tdLog.info("cluster is balanced")
+
+        nodes.removeConfigs("maxVgroupsPerDb", "10")
+        nodes.removeConfigs("maxTablesPerVnode", "1000")
+        nodes.restartAllTaosd()
+                                
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/basicTest.py
+++ b/tests/pytest/cluster/basicTest.py
@ -0,0 +1,47 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+
+    ## test case 1, 33 ##
+    def run(self):
+        
+        nodes = Nodes()        
+        ctest = ClusterTest(nodes.node1.hostName)
+
+        ctest.connectDB()
+        tdSql.init(ctest.conn.cursor(), False)
+
+        ## Test case 1 ##       
+        tdLog.info("Test case 1 repeat %d times" % ctest.repeat)
+        for i in range(ctest.repeat):
+            tdLog.info("Start Round %d" % (i + 1))
+            replica = random.randint(1,3)        
+            ctest.createSTable(replica) 
+            ctest.run()
+            tdLog.sleep(10)      
+            tdSql.query("select count(*) from %s.%s" %(ctest.dbName, ctest.stbName))
+            tdSql.checkData(0, 0, ctest.numberOfRecords * ctest.numberOfTables)            
+            tdLog.info("Round %d completed" % (i + 1))
+
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/changeReplicaTest.py
+++ b/tests/pytest/cluster/changeReplicaTest.py
@ -0,0 +1,51 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 7,  ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()        
+        tdSql.init(ctest.conn.cursor(), False)
+
+        tdSql.execute("use %s" % ctest.dbName)
+        tdSql.query("show vgroups")
+        for i in range(10):
+            tdSql.checkData(i, 5, "master")
+
+        tdSql.execute("alter database %s replica 2" % ctest.dbName)    
+        tdLog.sleep(30)
+        tdSql.query("show vgroups")
+        for i in range(10):
+            tdSql.checkData(i, 5, "master")
+            tdSql.checkData(i, 7, "slave")
+            
+        tdSql.execute("alter database %s replica 3" % ctest.dbName)
+        tdLog.sleep(30)
+        tdSql.query("show vgroups")
+        for i in range(10):
+            tdSql.checkData(i, 5, "master")
+            tdSql.checkData(i, 7, "slave")
+            tdSql.checkData(i, 9, "slave")
+        
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/clusterSetup.py
+++ b/tests/pytest/cluster/clusterSetup.py
@ -0,0 +1,202 @@
+###################################################################
+#           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 os
+import sys
+sys.path.insert(0, os.getcwd())
+from fabric import Connection
+from util.sql import *
+from util.log import *
+import taos
+import random
+import threading
+import logging
+
+class Node:
+    def __init__(self, index, username, hostIP, hostName, password, homeDir):
+        self.index = index        
+        self.username = username
+        self.hostIP = hostIP
+        self.hostName = hostName
+        self.homeDir = homeDir
+        self.conn = Connection("{}@{}".format(username, hostName), connect_kwargs={"password": "{}".format(password)}) 
+    
+    def startTaosd(self):
+        try:
+            self.conn.run("sudo systemctl start taosd")
+        except Exception as e:
+            print("Start Taosd error for node %d " % self.index)
+            logging.exception(e)
+        
+    def stopTaosd(self):
+        try:
+            self.conn.run("sudo systemctl stop taosd")
+        except Exception as e:
+            print("Stop Taosd error for node %d " % self.index)
+            logging.exception(e)
+    
+    def restartTaosd(self):
+        try:
+            self.conn.run("sudo systemctl restart taosd")
+        except Exception as e:
+            print("Stop Taosd error for node %d " % self.index)
+            logging.exception(e)
+
+    def removeTaosd(self):
+        try:
+            self.conn.run("rmtaos")
+        except Exception as e:
+            print("remove taosd error for node %d " % self.index)
+            logging.exception(e)
+    
+    def installTaosd(self, packagePath):
+        self.conn.put(packagePath, self.homeDir)
+        self.conn.cd(self.homeDir)
+        self.conn.run("tar -zxf $(basename '%s')" % packagePath)
+        with self.conn.cd("TDengine-enterprise-server"):
+            self.conn.run("yes|./install.sh")
+
+    def configTaosd(self, taosConfigKey, taosConfigValue):
+        self.conn.run("sudo echo '%s %s' >> %s" % (taosConfigKey, taosConfigValue, "/etc/taos/taos.cfg"))
+
+    def removeTaosConfig(self, taosConfigKey, taosConfigValue): 
+        self.conn.run("sudo sed -in-place -e '/%s %s/d' %s" % (taosConfigKey, taosConfigValue, "/etc/taos/taos.cfg"))
+    
+    def configHosts(self, ip, name):
+        self.conn.run("echo '%s %s' >> %s" % (ip, name, '/etc/hosts'))
+
+    def removeData(self):
+        try:
+            self.conn.run("sudo rm -rf /var/lib/taos/*")
+        except Exception as e:
+            print("remove taosd data error for node %d " % self.index)
+            logging.exception(e)
+    
+    def removeLog(self):
+        try:
+            self.conn.run("sudo rm -rf /var/log/taos/*")
+        except Exception as e:
+            print("remove taosd error for node %d " % self.index)
+            logging.exception(e)
+
+    def removeDataForMnode(self):
+        try:
+            self.conn.run("sudo rm -rf /var/lib/taos/*")
+        except Exception as e:
+            print("remove taosd error for node %d " % self.index)
+            logging.exception(e)
+
+    def removeDataForVnode(self, id):
+        try:
+            self.conn.run("sudo rm -rf /var/lib/taos/vnode%d/*.data" % id)
+        except Exception as e:
+            print("remove taosd error for node %d " % self.index)
+            logging.exception(e)
+
+class Nodes:
+    def __init__(self):
+        self.node1 = Node(1, 'ubuntu', '192.168.1.52', 'node1', 'tbase125!', '/home/ubuntu')
+        self.node2 = Node(2, 'ubuntu', '192.168.1.53', 'node2', 'tbase125!', '/home/ubuntu')
+        self.node3 = Node(3, 'ubuntu', '192.168.1.54', 'node3', 'tbase125!', '/home/ubuntu')
+
+    def stopAllTaosd(self):
+        self.node1.stopTaosd()
+        self.node2.stopTaosd()
+        self.node3.stopTaosd()
+    
+    def startAllTaosd(self):
+        self.node1.startTaosd()
+        self.node2.startTaosd()
+        self.node3.startTaosd()
+    
+    def restartAllTaosd(self):
+        self.node1.restartTaosd()
+        self.node2.restartTaosd()
+        self.node3.restartTaosd()
+    
+    def addConfigs(self, configKey, configValue):          
+        self.node1.configTaosd(configKey, configValue)
+        self.node2.configTaosd(configKey, configValue)
+        self.node3.configTaosd(configKey, configValue)
+    
+    def removeConfigs(self, configKey, configValue):          
+        self.node1.removeTaosConfig(configKey, configValue)
+        self.node2.removeTaosConfig(configKey, configValue)
+        self.node3.removeTaosConfig(configKey, configValue)        
+    
+    def removeAllDataFiles(self):
+        self.node1.removeData()
+        self.node2.removeData()
+        self.node3.removeData()
+
+class ClusterTest:
+    def __init__(self, hostName):
+        self.host = hostName
+        self.user = "root"
+        self.password = "taosdata"
+        self.config = "/etc/taos"        
+        self.dbName = "mytest"
+        self.stbName = "meters"
+        self.numberOfThreads = 20
+        self.numberOfTables = 10000
+        self.numberOfRecords = 1000
+        self.tbPrefix = "t"
+        self.ts = 1538548685000
+        self.repeat = 1        
+
+    def connectDB(self):
+        self.conn = taos.connect(
+            host=self.host,
+            user=self.user,
+            password=self.password,
+            config=self.config)
+
+    def createSTable(self, replica):
+        cursor = self.conn.cursor()
+        tdLog.info("drop database if exists %s" % self.dbName)
+        cursor.execute("drop database if exists %s" % self.dbName)
+        tdLog.info("create database %s replica %d" % (self.dbName, replica))
+        cursor.execute("create database %s replica %d" % (self.dbName, replica))
+        tdLog.info("use %s" % self.dbName)
+        cursor.execute("use %s" % self.dbName)
+        tdLog.info("drop table if exists %s" % self.stbName)
+        cursor.execute("drop table if exists %s" % self.stbName)
+        tdLog.info("create table %s(ts timestamp, current float, voltage int, phase int) tags(id int)" % self.stbName)
+        cursor.execute("create table %s(ts timestamp, current float, voltage int, phase int) tags(id int)" % self.stbName)
+        cursor.close()
+
+    def insertData(self, threadID):
+        print("Thread %d: starting" % threadID)
+        cursor = self.conn.cursor()
+        tablesPerThread = int(self.numberOfTables / self.numberOfThreads)
+        baseTableID = tablesPerThread * threadID
+        for i in range (tablesPerThread):
+            cursor.execute("create table %s%d using %s tags(%d)" % (self.tbPrefix, baseTableID + i, self.stbName, baseTableID + i))            
+            query = "insert into %s%d values" % (self.tbPrefix, baseTableID + i)
+            base = self.numberOfRecords * i            
+            for j in range(self.numberOfRecords):
+                query += "(%d, %f, %d, %d)" % (self.ts + base + j, random.random(), random.randint(210, 230), random.randint(0, 10)) 
+            cursor.execute(query)      
+        cursor.close()
+        print("Thread %d: finishing" % threadID)
+    
+    def run(self):        
+        threads = []
+        tdLog.info("Inserting data")
+        for i in range(self.numberOfThreads):
+            thread = threading.Thread(target=self.insertData, args=(i,))
+            threads.append(thread)
+            thread.start()
+
+        for i in range(self.numberOfThreads):
+            threads[i].join()
--- a/tests/pytest/cluster/dataFileRecoveryTest.py
+++ b/tests/pytest/cluster/dataFileRecoveryTest.py
@ -0,0 +1,53 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 20, 21, 22 ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()        
+        ctest.createSTable(3)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        nodes.node2.stopTaosd()
+        tdSql.execute("use %s" % ctest.dbName)        
+        tdSql.query("show vgroups")
+        vnodeID = tdSql.getData(0, 0)
+        nodes.node2.removeDataForVnode(vnodeID)
+        nodes.node2.startTaosd()
+
+        # Wait for vnode file to recover
+        for i in range(10):
+            tdSql.query("select count(*) from t0")
+        
+        tdLog.sleep(10)
+
+        for i in range(10):
+            tdSql.query("select count(*) from t0")
+            tdSql.checkData(0, 0, 1000)
+        
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/fullDnodesTest.py
+++ b/tests/pytest/cluster/fullDnodesTest.py
@ -0,0 +1,47 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ##Cover test case 5 ##
+    def run(self):
+        # cluster environment set up
+        nodes = Nodes()   
+        nodes.addConfigs("maxVgroupsPerDb", "10")
+        nodes.addConfigs("maxTablesPerVnode", "1000")
+        nodes.restartAllTaosd()
+
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()
+        ctest.createSTable(1)
+        ctest.run()
+
+        tdSql.init(ctest.conn.cursor(), False)
+        tdSql.execute("use %s" % ctest.dbName)
+        tdSql.error("create table tt1 using %s tags(1)" % ctest.stbName)
+
+        nodes.removeConfigs("maxVgroupsPerDb", "10")
+        nodes.removeConfigs("maxTablesPerVnode", "1000")
+        nodes.restartAllTaosd()
+
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+        
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/killAndRestartDnodesTest.py
+++ b/tests/pytest/cluster/killAndRestartDnodesTest.py
@ -0,0 +1,75 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 7, 10 ##
+    def run(self):
+        # cluster environment set up
+        tdLog.info("Test case 7, 10")
+
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()
+        tdSql.init(ctest.conn.cursor(), False)
+
+        nodes.node1.stopTaosd()
+        tdSql.query("show dnodes")
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "offline")
+        tdSql.checkData(1, 4, "ready")    
+        tdSql.checkData(2, 4, "ready")
+
+        nodes.node1.startTaosd()
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "ready")
+        tdSql.checkData(1, 4, "ready")    
+        tdSql.checkData(2, 4, "ready")
+
+        nodes.node2.stopTaosd()
+        tdSql.query("show dnodes")
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "ready")
+        tdSql.checkData(1, 4, "offline")    
+        tdSql.checkData(2, 4, "ready")
+
+        nodes.node2.startTaosd()
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "ready")
+        tdSql.checkData(1, 4, "ready")    
+        tdSql.checkData(2, 4, "ready")
+
+        nodes.node3.stopTaosd()
+        tdSql.query("show dnodes")
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "ready")
+        tdSql.checkData(1, 4, "ready")    
+        tdSql.checkData(2, 4, "offline")
+
+        nodes.node3.startTaosd()
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 4, "ready")
+        tdSql.checkData(1, 4, "ready")    
+        tdSql.checkData(2, 4, "ready")
+        
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/offlineThresholdTest.py
+++ b/tests/pytest/cluster/offlineThresholdTest.py
@ -0,0 +1,54 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## cover test case 6, 8, 9, 11 ##
+    def run(self):
+        # cluster environment set up
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()
+        tdSql.init(ctest.conn.cursor(), False)
+
+        nodes.addConfigs("offlineThreshold", "10")
+        nodes.removeAllDataFiles()
+        nodes.restartAllTaosd()
+        nodes.node3.stopTaosd()
+
+        tdLog.sleep(10)
+        tdSql.query("show dnodes")
+        tdSql.checkRows(3)
+        tdSql.checkData(2, 4, "offline")
+
+        tdLog.sleep(60)
+        tdSql.checkRows(3)
+        tdSql.checkData(2, 4, "dropping")        
+
+        tdLog.sleep(300)
+        tdSql.checkRows(2)                
+
+        nodes.removeConfigs("offlineThreshold", "10")
+        nodes.restartAllTaosd()
+        
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/oneReplicaOfflineTest.py
+++ b/tests/pytest/cluster/oneReplicaOfflineTest.py
@ -0,0 +1,65 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 28, 29, 30, 31 ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()        
+        ctest.createSTable(3)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        tdSql.execute("use %s" % ctest.dbName) 
+        
+        nodes.node2.stopTaosd()                        
+        for i in range(100):
+            tdSql.execute("drop table t%d" % i)
+        
+        nodes.node2.startTaosd()
+        tdSql.query("show tables")
+        tdSql.checkRows(9900)
+        
+        nodes.node2.stopTaosd()
+        for i in range(10):
+            tdSql.execute("create table a%d using meters tags(2)" % i)
+
+        nodes.node2.startTaosd()
+        tdSql.query("show tables")
+        tdSql.checkRows(9910)
+
+        nodes.node2.stopTaosd()        
+        tdSql.execute("alter table meters add col col6 int")
+        nodes.node2.startTaosd()        
+        
+        nodes.node2.stopTaosd()        
+        tdSql.execute("drop database %s" % ctest.dbName)
+        
+        nodes.node2.startTaosd()
+        tdSql.query("show databases")
+        tdSql.checkRows(0)
+        
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/queryTimeTest.py
+++ b/tests/pytest/cluster/queryTimeTest.py
@ -0,0 +1,54 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+import time
+
+class ClusterTestcase:
+    
+    ## test case 32 ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()                
+        ctest.createSTable(1)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        tdSql.execute("use %s" % ctest.dbName) 
+        totalTime = 0
+        for i in range(10):
+            startTime = time.time()
+            tdSql.query("select * from %s" % ctest.stbName)
+            totalTime += time.time() - startTime
+        print("replica 1: avarage query time for %d records: %f seconds" % (ctest.numberOfTables * ctest.numberOfRecords,totalTime / 10))
+
+        tdSql.execute("alter database %s replica 3" % ctest.dbName)
+        tdLog.sleep(60)
+        totalTime = 0
+        for i in range(10):
+            startTime = time.time()
+            tdSql.query("select * from %s" % ctest.stbName)
+            totalTime += time.time() - startTime
+        print("replica 3: avarage query time for %d records: %f seconds" % (ctest.numberOfTables * ctest.numberOfRecords,totalTime / 10))
+                                
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/stopAllDnodesTest.py
+++ b/tests/pytest/cluster/stopAllDnodesTest.py
@ -0,0 +1,45 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 19 ##
+    def run(self):
+
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        tdSql.init(ctest.conn.cursor(), False)
+                
+        tdSql.query("show databases")
+        count = tdSql.queryRows;
+
+        nodes.stopAllTaosd()
+        nodes.node1.startTaosd()
+        tdSql.error("show databases")
+
+        nodes.node2.startTaosd()
+        tdSql.error("show databases")
+
+        nodes.node3.startTaosd()
+        tdLog.sleep(10)
+        tdSql.query("show databases")
+        tdSql.checkRows(count)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/stopTwoDnodesTest.py
+++ b/tests/pytest/cluster/stopTwoDnodesTest.py
@ -0,0 +1,48 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 17, 18 ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()        
+        ctest.createSTable(1)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        tdSql.query("show databases")
+        count = tdSql.queryRows;
+        tdSql.execute("use %s" % ctest.dbName)
+        tdSql.execute("alter database %s replica 3" % ctest.dbName)    
+        nodes.node2.stopTaosd()
+        nodes.node3.stopTaosd()
+        tdSql.error("show databases")
+        
+        nodes.node2.startTaosd()
+        tdSql.error("show databases")
+
+        nodes.node3.startTaosd()
+        tdSql.query("show databases")
+        tdSql.checkRows(count)
+        
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/syncingTest.py
+++ b/tests/pytest/cluster/syncingTest.py
@ -0,0 +1,50 @@
+###################################################################
+#           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
+from clusterSetup import *
+from util.sql import tdSql
+from util.log import tdLog
+import random
+
+class ClusterTestcase:
+    
+    ## test case 24, 25, 26, 27 ##
+    def run(self):
+        
+        nodes = Nodes()
+        ctest = ClusterTest(nodes.node1.hostName)
+        ctest.connectDB()        
+        ctest.createSTable(1)
+        ctest.run()
+        tdSql.init(ctest.conn.cursor(), False)
+        
+        
+        tdSql.execute("use %s" % ctest.dbName)        
+        tdSql.execute("alter database %s replica 3" % ctest.dbName)
+        
+        for i in range(100):
+            tdSql.execute("drop table t%d" % i)
+        
+        for i in range(100):
+            tdSql.execute("create table a%d using meters tags(1)" % i)
+        
+        tdSql.execute("alter table meters add col col5 int")
+        tdSql.execute("alter table meters drop col col5 int")
+        tdSql.execute("drop database %s" % ctest.dbName)
+        
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+ct = ClusterTestcase()
+ct.run()
--- a/tests/pytest/cluster/testcluster.sh
+++ b/tests/pytest/cluster/testcluster.sh
@ -0,0 +1,12 @@
+python3 basicTest.py
+python3 bananceTest.py
+python3 changeReplicaTest.py
+python3 dataFileRecoveryTest.py
+python3 fullDnodesTest.py
+python3 killAndRestartDnodesTest.py
+python3 offlineThresholdTest.py
+python3 oneReplicaOfflineTest.py
+python3 queryTimeTest.py
+python3 stopAllDnodesTest.py
+python3 stopTwoDnodesTest.py
+python3 syncingTest.py
--- a/tests/pytest/crash_gen.sh
+++ b/tests/pytest/crash_gen.sh
@ -54,6 +54,7 @@ export PYTHONPATH=$(pwd)/../../src/connector/python/linux/python3:$(pwd)
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$LIB_DIR

 # Now we are all let, and let's see if we can find a crash. Note we pass all params
+CRASH_GEN_EXEC=crash_gen_bootstrap.py
 if [[ $1 == '--valgrind' ]]; then
  shift
  export PYTHONMALLOC=malloc
@ -66,14 +67,14 @@ if [[ $1 == '--valgrind' ]]; then
    --leak-check=yes \
    --suppressions=crash_gen/valgrind_taos.supp \
    $PYTHON_EXEC \
-    ./crash_gen/crash_gen.py $@ > $VALGRIND_OUT 2> $VALGRIND_ERR 
+    $CRASH_GEN_EXEC $@ > $VALGRIND_OUT 2> $VALGRIND_ERR 
 elif [[ $1 == '--helgrind' ]]; then
  shift
  valgrind  \
    --tool=helgrind \
    $PYTHON_EXEC \
-    ./crash_gen/crash_gen.py $@
+    $CRASH_GEN_EXEC $@
 else
-  $PYTHON_EXEC ./crash_gen/crash_gen.py $@
+  $PYTHON_EXEC $CRASH_GEN_EXEC $@
 fi

--- a/tests/pytest/crash_gen/README.md
+++ b/tests/pytest/crash_gen/README.md
@ -0,0 +1,130 @@
+<center><h1>User's Guide to the Crash_Gen Tool</h1></center>
+
+# Introduction
+
+To effectively test and debug our TDengine product, we have developed a simple tool to 
+exercise various functions of the system in a randomized fashion, hoping to expose 
+maximum number of problems, hopefully without a pre-determined scenario.
+
+# Preparation
+
+To run this tool, please ensure the followed preparation work is done first.
+
+1. Fetch a copy of the TDengine source code, and build it successfully in the `build/` 
+    directory
+1. Ensure that the system has Python3.8 or above properly installed. We use 
+    Ubuntu 20.04LTS as our own development environment, and suggest you also use such
+    an environment if possible.
+
+# Simple Execution
+
+To run the tool with the simplest method, follow the steps below:
+
+1. Open a terminal window, start the `taosd` service in the `build/` directory 
+    (or however you prefer to start the `taosd` service)
+1. Open another terminal window, go into the `tests/pytest/` directory, and
+    run `./crash_gen.sh -p -t 3 -s 10` (change the two parameters here as you wish)
+1. Watch the output to the end and see if you get a `SUCCESS` or `FAILURE`
+
+That's it!
+
+# Running Clusters
+
+This tool also makes it easy to test/verify the clustering capabilities of TDengine. You
+can start a cluster quite easily with the following command:
+
+```
+$ cd tests/pytest/
+$ ./crash_gen.sh -e -o 3
+```
+
+The `-e` option above tells the tool to start the service, and do not run any tests, while 
+the `-o 3` option tells the tool to start 3 DNodes and join them together in a cluster. 
+Obviously you can adjust the the number here.
+
+## Behind the Scenes
+
+When the tool runs a cluster, it users a number of directories, each holding the information
+for a single DNode, see:
+
+```
+$ ls build/cluster*
+build/cluster_dnode_0:
+cfg  data  log
+
+build/cluster_dnode_1:
+cfg  data  log
+
+build/cluster_dnode_2:
+cfg  data  log
+```
+
+Therefore, when something goes wrong and you want to reset everything with the cluster, simple
+erase all the files:
+
+```
+$ rm -rf build/cluster_dnode_*
+```
+
+## Addresses and Ports
+
+The DNodes in the cluster all binds the the `127.0.0.1` IP address (for now anyway), and
+uses port 6030 for the first DNode, and 6130 for the 2nd one, and so on.
+
+## Testing Against a Cluster
+
+In a separate terminal window, you can invoke the tool in client mode and test against
+a cluster, such as:
+
+```
+$ ./crash_gen.sh -p -t 10 -s 100 -i 3
+```
+
+Here the `-i` option tells the tool to always create tables with 3 replicas, and run 
+all tests against such tables.
+
+# Additional Features
+
+The exhaustive features of the tool is available through the `-h` option:
+
+```
+$ ./crash_gen.sh -h
+usage: crash_gen_bootstrap.py [-h] [-a] [-b MAX_DBS] [-c CONNECTOR_TYPE] [-d] [-e] [-g IGNORE_ERRORS] [-i MAX_REPLICAS] [-l] [-n] [-o NUM_DNODES] [-p] [-r]
+                              [-s MAX_STEPS] [-t NUM_THREADS] [-v] [-x]
+
+TDengine Auto Crash Generator (PLEASE NOTICE the Prerequisites Below)
+---------------------------------------------------------------------
+1. You build TDengine in the top level ./build directory, as described in offical docs
+2. You run the server there before this script: ./build/bin/taosd -c test/cfg
+
+optional arguments:
+  -h, --help            show this help message and exit
+  -a, --auto-start-service
+                        Automatically start/stop the TDengine service (default: false)
+  -b MAX_DBS, --max-dbs MAX_DBS
+                        Maximum number of DBs to keep, set to disable dropping DB. (default: 0)
+  -c CONNECTOR_TYPE, --connector-type CONNECTOR_TYPE
+                        Connector type to use: native, rest, or mixed (default: 10)
+  -d, --debug           Turn on DEBUG mode for more logging (default: false)
+  -e, --run-tdengine    Run TDengine service in foreground (default: false)
+  -g IGNORE_ERRORS, --ignore-errors IGNORE_ERRORS
+                        Ignore error codes, comma separated, 0x supported (default: None)
+  -i MAX_REPLICAS, --max-replicas MAX_REPLICAS
+                        Maximum number of replicas to use, when testing against clusters. (default: 1)
+  -l, --larger-data     Write larger amount of data during write operations (default: false)
+  -n, --dynamic-db-table-names
+                        Use non-fixed names for dbs/tables, useful for multi-instance executions (default: false)
+  -o NUM_DNODES, --num-dnodes NUM_DNODES
+                        Number of Dnodes to initialize, used with -e option. (default: 1)
+  -p, --per-thread-db-connection
+                        Use a single shared db connection (default: false)
+  -r, --record-ops      Use a pair of always-fsynced fils to record operations performing + performed, for power-off tests (default: false)
+  -s MAX_STEPS, --max-steps MAX_STEPS
+                        Maximum number of steps to run (default: 100)
+  -t NUM_THREADS, --num-threads NUM_THREADS
+                        Number of threads to run (default: 10)
+  -v, --verify-data     Verify data written in a number of places by reading back (default: false)
+  -x, --continue-on-exception
+                        Continue execution after encountering unexpected/disallowed errors/exceptions (default: false)
+```
+
--- a/tests/pytest/crash_gen/crash_gen.py
+++ b/tests/pytest/crash_gen/crash_gen.py
--- a/tests/pytest/crash_gen/db.py
+++ b/tests/pytest/crash_gen/db.py
@ -0,0 +1,435 @@
+from __future__ import annotations
+
+import sys
+import time
+import threading
+import requests
+from requests.auth import HTTPBasicAuth
+
+import taos
+from util.sql import *
+from util.cases import *
+from util.dnodes import *
+from util.log import *
+
+from .misc import Logging, CrashGenError, Helper, Dice
+import os
+import datetime
+# from .service_manager import TdeInstance
+
+class DbConn:
+    TYPE_NATIVE = "native-c"
+    TYPE_REST =   "rest-api"
+    TYPE_INVALID = "invalid"
+
+    @classmethod
+    def create(cls, connType, dbTarget):
+        if connType == cls.TYPE_NATIVE:
+            return DbConnNative(dbTarget)
+        elif connType == cls.TYPE_REST:
+            return DbConnRest(dbTarget)
+        else:
+            raise RuntimeError(
+                "Unexpected connection type: {}".format(connType))
+
+    @classmethod
+    def createNative(cls, dbTarget) -> DbConn:
+        return cls.create(cls.TYPE_NATIVE, dbTarget)
+
+    @classmethod
+    def createRest(cls, dbTarget) -> DbConn:
+        return cls.create(cls.TYPE_REST, dbTarget)
+
+    def __init__(self, dbTarget):
+        self.isOpen = False
+        self._type = self.TYPE_INVALID
+        self._lastSql = None
+        self._dbTarget = dbTarget
+
+    def __repr__(self):
+        return "[DbConn: type={}, target={}]".format(self._type, self._dbTarget)
+
+    def getLastSql(self):
+        return self._lastSql
+
+    def open(self):
+        if (self.isOpen):
+            raise RuntimeError("Cannot re-open an existing DB connection")
+
+        # below implemented by child classes
+        self.openByType()
+
+        Logging.debug("[DB] data connection opened: {}".format(self))
+        self.isOpen = True
+
+    def close(self):
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def queryScalar(self, sql) -> int:
+        return self._queryAny(sql)
+
+    def queryString(self, sql) -> str:
+        return self._queryAny(sql)
+
+    def _queryAny(self, sql):  # actual query result as an int
+        if (not self.isOpen):
+            raise RuntimeError("Cannot query database until connection is open")
+        nRows = self.query(sql)
+        if nRows != 1:
+            raise taos.error.ProgrammingError(
+                "Unexpected result for query: {}, rows = {}".format(sql, nRows), 
+                (0x991 if nRows==0 else 0x992)
+            )
+        if self.getResultRows() != 1 or self.getResultCols() != 1:
+            raise RuntimeError("Unexpected result set for query: {}".format(sql))
+        return self.getQueryResult()[0][0]
+
+    def use(self, dbName):
+        self.execute("use {}".format(dbName))
+
+    def existsDatabase(self, dbName: str):
+        ''' Check if a certain database exists '''
+        self.query("show databases")
+        dbs = [v[0] for v in self.getQueryResult()] # ref: https://stackoverflow.com/questions/643823/python-list-transformation
+        # ret2 = dbName in dbs
+        # print("dbs = {}, str = {}, ret2={}, type2={}".format(dbs, dbName,ret2, type(dbName)))
+        return dbName in dbs # TODO: super weird type mangling seen, once here
+
+    def hasTables(self):
+        return self.query("show tables") > 0
+
+    def execute(self, sql):
+        ''' Return the number of rows affected'''
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def safeExecute(self, sql):
+        '''Safely execute any SQL query, returning True/False upon success/failure'''
+        try:
+            self.execute(sql)
+            return True # ignore num of results, return success
+        except taos.error.ProgrammingError as err:
+            return False # failed, for whatever TAOS reason
+        # Not possile to reach here, non-TAOS exception would have been thrown
+
+    def query(self, sql) -> int: # return num rows returned
+        ''' Return the number of rows affected'''
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def openByType(self):
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def getQueryResult(self):
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def getResultRows(self):
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+    def getResultCols(self):
+        raise RuntimeError("Unexpected execution, should be overriden")
+
+# Sample: curl -u root:taosdata -d "show databases" localhost:6020/rest/sql
+
+
+class DbConnRest(DbConn):
+    REST_PORT_INCREMENT = 11
+
+    def __init__(self, dbTarget: DbTarget):
+        super().__init__(dbTarget)
+        self._type = self.TYPE_REST
+        restPort = dbTarget.port + 11
+        self._url = "http://{}:{}/rest/sql".format(
+            dbTarget.hostAddr, dbTarget.port + self.REST_PORT_INCREMENT)
+        self._result = None
+
+    def openByType(self):  # Open connection        
+        pass  # do nothing, always open
+
+    def close(self):
+        if (not self.isOpen):
+            raise RuntimeError("Cannot clean up database until connection is open")
+        # Do nothing for REST
+        Logging.debug("[DB] REST Database connection closed")
+        self.isOpen = False
+
+    def _doSql(self, sql):
+        self._lastSql = sql # remember this, last SQL attempted
+        try:
+            r = requests.post(self._url, 
+                data = sql,
+                auth = HTTPBasicAuth('root', 'taosdata'))         
+        except:
+            print("REST API Failure (TODO: more info here)")
+            raise
+        rj = r.json()
+        # Sanity check for the "Json Result"
+        if ('status' not in rj):
+            raise RuntimeError("No status in REST response")
+
+        if rj['status'] == 'error':  # clearly reported error
+            if ('code' not in rj):  # error without code
+                raise RuntimeError("REST error return without code")
+            errno = rj['code']  # May need to massage this in the future
+            # print("Raising programming error with REST return: {}".format(rj))
+            raise taos.error.ProgrammingError(
+                rj['desc'], errno)  # todo: check existance of 'desc'
+
+        if rj['status'] != 'succ':  # better be this
+            raise RuntimeError(
+                "Unexpected REST return status: {}".format(
+                    rj['status']))
+
+        nRows = rj['rows'] if ('rows' in rj) else 0
+        self._result = rj
+        return nRows
+
+    def execute(self, sql):
+        if (not self.isOpen):
+            raise RuntimeError(
+                "Cannot execute database commands until connection is open")
+        Logging.debug("[SQL-REST] Executing SQL: {}".format(sql))
+        nRows = self._doSql(sql)
+        Logging.debug(
+            "[SQL-REST] Execution Result, nRows = {}, SQL = {}".format(nRows, sql))
+        return nRows
+
+    def query(self, sql):  # return rows affected
+        return self.execute(sql)
+
+    def getQueryResult(self):
+        return self._result['data']
+
+    def getResultRows(self):
+        print(self._result)
+        raise RuntimeError("TBD") # TODO: finish here to support -v under -c rest
+        # return self._tdSql.queryRows
+
+    def getResultCols(self):
+        print(self._result)
+        raise RuntimeError("TBD")
+
+    # Duplicate code from TDMySQL, TODO: merge all this into DbConnNative
+
+
+class MyTDSql:
+    # Class variables
+    _clsLock = threading.Lock() # class wide locking
+    longestQuery = None # type: str
+    longestQueryTime = 0.0 # seconds
+    lqStartTime = 0.0
+    # lqEndTime = 0.0 # Not needed, as we have the two above already
+
+    def __init__(self, hostAddr, cfgPath):
+        # Make the DB connection
+        self._conn = taos.connect(host=hostAddr, config=cfgPath) 
+        self._cursor = self._conn.cursor()
+
+        self.queryRows = 0
+        self.queryCols = 0
+        self.affectedRows = 0
+
+    # def init(self, cursor, log=True):
+    #     self.cursor = cursor
+        # if (log):
+        #     caller = inspect.getframeinfo(inspect.stack()[1][0])
+        #     self.cursor.log(caller.filename + ".sql")
+
+    def close(self):
+        self._cursor.close() # can we double close?
+        self._conn.close() # TODO: very important, cursor close does NOT close DB connection!
+        self._cursor.close()
+
+    def _execInternal(self, sql):
+        startTime = time.time() 
+        ret = self._cursor.execute(sql)
+        # print("\nSQL success: {}".format(sql))
+        queryTime =  time.time() - startTime
+        # Record the query time
+        cls = self.__class__
+        if queryTime > (cls.longestQueryTime + 0.01) :
+            with cls._clsLock:
+                cls.longestQuery = sql
+                cls.longestQueryTime = queryTime
+                cls.lqStartTime = startTime
+        return ret
+
+    def query(self, sql):
+        self.sql = sql
+        try:
+            self._execInternal(sql)
+            self.queryResult = self._cursor.fetchall()
+            self.queryRows = len(self.queryResult)
+            self.queryCols = len(self._cursor.description)
+        except Exception as e:
+            # caller = inspect.getframeinfo(inspect.stack()[1][0])
+            # args = (caller.filename, caller.lineno, sql, repr(e))
+            # tdLog.exit("%s(%d) failed: sql:%s, %s" % args)
+            raise
+        return self.queryRows
+
+    def execute(self, sql):
+        self.sql = sql
+        try:
+            self.affectedRows = self._execInternal(sql)
+        except Exception as e:
+            # caller = inspect.getframeinfo(inspect.stack()[1][0])
+            # args = (caller.filename, caller.lineno, sql, repr(e))
+            # tdLog.exit("%s(%d) failed: sql:%s, %s" % args)
+            raise
+        return self.affectedRows
+
+class DbTarget:
+    def __init__(self, cfgPath, hostAddr, port):
+        self.cfgPath  = cfgPath
+        self.hostAddr = hostAddr
+        self.port     = port
+    
+    def __repr__(self):
+        return "[DbTarget: cfgPath={}, host={}:{}]".format(
+            Helper.getFriendlyPath(self.cfgPath), self.hostAddr, self.port)
+
+    def getEp(self):
+        return "{}:{}".format(self.hostAddr, self.port)
+
+class DbConnNative(DbConn):
+    # Class variables
+    _lock = threading.Lock()
+    # _connInfoDisplayed = False # TODO: find another way to display this
+    totalConnections = 0 # Not private
+
+    def __init__(self, dbTarget):
+        super().__init__(dbTarget)
+        self._type = self.TYPE_NATIVE
+        self._conn = None
+        # self._cursor = None        
+
+    def openByType(self):  # Open connection
+        # global gContainer
+        # tInst = tInst or gContainer.defTdeInstance # set up in ClientManager, type: TdeInstance
+        # cfgPath = self.getBuildPath() + "/test/cfg"
+        # cfgPath  = tInst.getCfgDir()
+        # hostAddr = tInst.getHostAddr()
+
+        cls = self.__class__ # Get the class, to access class variables
+        with cls._lock: # force single threading for opening DB connections. # TODO: whaaat??!!!
+            dbTarget = self._dbTarget
+            # if not cls._connInfoDisplayed:
+            #     cls._connInfoDisplayed = True # updating CLASS variable
+            Logging.debug("Initiating TAOS native connection to {}".format(dbTarget))                    
+            # Make the connection         
+            # self._conn = taos.connect(host=hostAddr, config=cfgPath)  # TODO: make configurable
+            # self._cursor = self._conn.cursor()
+            # Record the count in the class
+            self._tdSql = MyTDSql(dbTarget.hostAddr, dbTarget.cfgPath) # making DB connection
+            cls.totalConnections += 1 
+        
+        self._tdSql.execute('reset query cache')
+        # self._cursor.execute('use db') # do this at the beginning of every
+
+        # Open connection
+        # self._tdSql = MyTDSql()
+        # self._tdSql.init(self._cursor)
+        
+    def close(self):
+        if (not self.isOpen):
+            raise RuntimeError("Cannot clean up database until connection is open")
+        self._tdSql.close()
+        # Decrement the class wide counter
+        cls = self.__class__ # Get the class, to access class variables
+        with cls._lock:
+            cls.totalConnections -= 1
+
+        Logging.debug("[DB] Database connection closed")
+        self.isOpen = False
+
+    def execute(self, sql):
+        if (not self.isOpen):
+            raise RuntimeError("Cannot execute database commands until connection is open")
+        Logging.debug("[SQL] Executing SQL: {}".format(sql))
+        self._lastSql = sql
+        nRows = self._tdSql.execute(sql)
+        Logging.debug(
+            "[SQL] Execution Result, nRows = {}, SQL = {}".format(
+                nRows, sql))
+        return nRows
+
+    def query(self, sql):  # return rows affected
+        if (not self.isOpen):
+            raise RuntimeError(
+                "Cannot query database until connection is open")
+        Logging.debug("[SQL] Executing SQL: {}".format(sql))
+        self._lastSql = sql
+        nRows = self._tdSql.query(sql)
+        Logging.debug(
+            "[SQL] Query Result, nRows = {}, SQL = {}".format(
+                nRows, sql))
+        return nRows
+        # results are in: return self._tdSql.queryResult
+
+    def getQueryResult(self):
+        return self._tdSql.queryResult
+
+    def getResultRows(self):
+        return self._tdSql.queryRows
+
+    def getResultCols(self):
+        return self._tdSql.queryCols
+
+
+class DbManager():
+    ''' This is a wrapper around DbConn(), to make it easier to use. 
+
+        TODO: rename this to DbConnManager
+    '''
+    def __init__(self, cType, dbTarget):
+        # self.tableNumQueue = LinearQueue() # TODO: delete?
+        # self.openDbServerConnection()
+        self._dbConn = DbConn.createNative(dbTarget) if (
+            cType == 'native') else DbConn.createRest(dbTarget)
+        try:
+            self._dbConn.open()  # may throw taos.error.ProgrammingError: disconnected
+        except taos.error.ProgrammingError as err:
+            # print("Error type: {}, msg: {}, value: {}".format(type(err), err.msg, err))
+            if (err.msg == 'client disconnected'):  # cannot open DB connection
+                print(
+                    "Cannot establish DB connection, please re-run script without parameter, and follow the instructions.")
+                sys.exit(2)
+            else:
+                print("Failed to connect to DB, errno = {}, msg: {}"
+                    .format(Helper.convertErrno(err.errno), err.msg))
+                raise
+        except BaseException:
+            print("[=] Unexpected exception")
+            raise
+
+        # Do this after dbConn is in proper shape
+        # Moved to Database()
+        # self._stateMachine = StateMechine(self._dbConn)
+
+    def getDbConn(self):
+        return self._dbConn
+
+    # TODO: not used any more, to delete
+    def pickAndAllocateTable(self):  # pick any table, and "use" it
+        return self.tableNumQueue.pickAndAllocate()
+
+    # TODO: Not used any more, to delete
+    def addTable(self):
+        with self._lock:
+            tIndex = self.tableNumQueue.push()
+        return tIndex
+
+    # Not used any more, to delete
+    def releaseTable(self, i):  # return the table back, so others can use it
+        self.tableNumQueue.release(i)    
+
+    # TODO: not used any more, delete
+    def getTableNameToDelete(self):
+        tblNum = self.tableNumQueue.pop()  # TODO: race condition!
+        if (not tblNum):  # maybe false
+            return False
+
+        return "table_{}".format(tblNum)
+
+    def cleanUp(self):
+        self._dbConn.close()
+
--- a/tests/pytest/crash_gen/misc.py
+++ b/tests/pytest/crash_gen/misc.py
@ -0,0 +1,175 @@
+import threading
+import random
+import logging
+import os
+
+
+class CrashGenError(Exception):
+    def __init__(self, msg=None, errno=None):
+        self.msg = msg
+        self.errno = errno
+
+    def __str__(self):
+        return self.msg
+
+
+class LoggingFilter(logging.Filter):
+    def filter(self, record: logging.LogRecord):
+        if (record.levelno >= logging.INFO):
+            return True  # info or above always log
+
+        # Commenting out below to adjust...
+
+        # if msg.startswith("[TRD]"):
+        #     return False
+        return True
+
+
+class MyLoggingAdapter(logging.LoggerAdapter):
+    def process(self, msg, kwargs):
+        return "[{}] {}".format(threading.get_ident() % 10000, msg), kwargs
+        # return '[%s] %s' % (self.extra['connid'], msg), kwargs
+
+
+class Logging:
+    logger = None
+
+    @classmethod
+    def getLogger(cls):
+        return logger
+
+    @classmethod
+    def clsInit(cls, gConfig): # TODO: refactor away gConfig
+        if cls.logger:
+            return
+        
+        # Logging Stuff
+        # global misc.logger
+        _logger = logging.getLogger('CrashGen')  # real logger
+        _logger.addFilter(LoggingFilter())
+        ch = logging.StreamHandler()
+        _logger.addHandler(ch)
+
+        # Logging adapter, to be used as a logger
+        print("setting logger variable")
+        # global logger
+        cls.logger = MyLoggingAdapter(_logger, [])
+
+        if (gConfig.debug):
+            cls.logger.setLevel(logging.DEBUG)  # default seems to be INFO
+        else:
+            cls.logger.setLevel(logging.INFO)
+
+    @classmethod
+    def info(cls, msg):
+        cls.logger.info(msg)
+
+    @classmethod
+    def debug(cls, msg):
+        cls.logger.debug(msg)
+
+    @classmethod
+    def warning(cls, msg):
+        cls.logger.warning(msg)
+
+    @classmethod
+    def error(cls, msg):
+        cls.logger.error(msg)
+
+class Status:
+    STATUS_STARTING = 1
+    STATUS_RUNNING  = 2
+    STATUS_STOPPING = 3
+    STATUS_STOPPED  = 4
+
+    def __init__(self, status):
+        self.set(status)
+
+    def __repr__(self):
+        return "[Status: v={}]".format(self._status)
+
+    def set(self, status):
+        self._status = status
+
+    def get(self):
+        return self._status
+
+    def isStarting(self):
+        return self._status == Status.STATUS_STARTING
+
+    def isRunning(self):
+        # return self._thread and self._thread.is_alive()
+        return self._status == Status.STATUS_RUNNING
+
+    def isStopping(self):
+        return self._status == Status.STATUS_STOPPING
+
+    def isStopped(self):
+        return self._status == Status.STATUS_STOPPED
+
+    def isStable(self):
+        return self.isRunning() or self.isStopped()
+
+# Deterministic random number generator
+class Dice():
+    seeded = False  # static, uninitialized
+
+    @classmethod
+    def seed(cls, s):  # static
+        if (cls.seeded):
+            raise RuntimeError(
+                "Cannot seed the random generator more than once")
+        cls.verifyRNG()
+        random.seed(s)
+        cls.seeded = True  # TODO: protect against multi-threading
+
+    @classmethod
+    def verifyRNG(cls):  # Verify that the RNG is determinstic
+        random.seed(0)
+        x1 = random.randrange(0, 1000)
+        x2 = random.randrange(0, 1000)
+        x3 = random.randrange(0, 1000)
+        if (x1 != 864 or x2 != 394 or x3 != 776):
+            raise RuntimeError("System RNG is not deterministic")
+
+    @classmethod
+    def throw(cls, stop):  # get 0 to stop-1
+        return cls.throwRange(0, stop)
+
+    @classmethod
+    def throwRange(cls, start, stop):  # up to stop-1
+        if (not cls.seeded):
+            raise RuntimeError("Cannot throw dice before seeding it")
+        return random.randrange(start, stop)
+
+    @classmethod
+    def choice(cls, cList):
+        return random.choice(cList)
+
+class Helper:
+    @classmethod
+    def convertErrno(cls, errno):
+        return errno if (errno > 0) else 0x80000000 + errno
+
+    @classmethod
+    def getFriendlyPath(cls, path): # returns .../xxx/yyy
+        ht1 = os.path.split(path)
+        ht2 = os.path.split(ht1[0])
+        return ".../" + ht2[1] + '/' + ht1[1]
+
+
+class Progress:
+    STEP_BOUNDARY = 0
+    BEGIN_THREAD_STEP = 1
+    END_THREAD_STEP   = 2
+    SERVICE_HEART_BEAT= 3
+    tokens = {
+        STEP_BOUNDARY:      '.',
+        BEGIN_THREAD_STEP:  '[',
+        END_THREAD_STEP:    '] ',
+        SERVICE_HEART_BEAT: '.Y.'
+    }
+
+    @classmethod
+    def emit(cls, token):
+        print(cls.tokens[token], end="", flush=True)
--- a/tests/pytest/crash_gen/service_manager.py
+++ b/tests/pytest/crash_gen/service_manager.py
@ -0,0 +1,729 @@
+import os
+import io
+import sys
+import threading
+import signal
+import logging
+import time
+import subprocess
+
+from typing import IO, List
+
+try:
+    import psutil
+except:
+    print("Psutil module needed, please install: sudo pip3 install psutil")
+    sys.exit(-1)
+
+from queue import Queue, Empty
+
+from .misc import Logging, Status, CrashGenError, Dice, Helper, Progress
+from .db import DbConn, DbTarget
+
+class TdeInstance():
+    """
+    A class to capture the *static* information of a TDengine instance,
+    including the location of the various files/directories, and basica
+    configuration.
+    """
+
+    @classmethod
+    def _getBuildPath(cls):
+        selfPath = os.path.dirname(os.path.realpath(__file__))
+        if ("community" in selfPath):
+            projPath = selfPath[:selfPath.find("communit")]
+        else:
+            projPath = selfPath[:selfPath.find("tests")]
+
+        buildPath = None
+        for root, dirs, files in os.walk(projPath):
+            if ("taosd" in files):
+                rootRealPath = os.path.dirname(os.path.realpath(root))
+                if ("packaging" not in rootRealPath):
+                    buildPath = root[:len(root) - len("/build/bin")]
+                    break
+        if buildPath == None:
+            raise RuntimeError("Failed to determine buildPath, selfPath={}, projPath={}"
+                .format(selfPath, projPath))
+        return buildPath
+
+    def __init__(self, subdir='test', tInstNum=0, port=6030, fepPort=6030):
+        self._buildDir  = self._getBuildPath()
+        self._subdir    = '/' + subdir # TODO: tolerate "/"
+        self._port      = port # TODO: support different IP address too
+        self._fepPort   = fepPort
+
+        self._tInstNum    = tInstNum
+        self._smThread    = ServiceManagerThread()
+
+    def getDbTarget(self):
+        return DbTarget(self.getCfgDir(), self.getHostAddr(), self._port)
+
+    def getPort(self):
+        return self._port
+
+    def __repr__(self):
+        return "[TdeInstance: {}, subdir={}]".format(
+            self._buildDir, Helper.getFriendlyPath(self._subdir))
+    
+    def generateCfgFile(self):       
+        # print("Logger = {}".format(logger))
+        # buildPath = self.getBuildPath()
+        # taosdPath = self._buildPath + "/build/bin/taosd"
+
+        cfgDir  = self.getCfgDir()
+        cfgFile = cfgDir + "/taos.cfg" # TODO: inquire if this is fixed
+        if os.path.exists(cfgFile):
+            if os.path.isfile(cfgFile):
+                Logging.warning("Config file exists already, skip creation: {}".format(cfgFile))
+                return # cfg file already exists, nothing to do
+            else:
+                raise CrashGenError("Invalid config file: {}".format(cfgFile))
+        # Now that the cfg file doesn't exist
+        if os.path.exists(cfgDir):
+            if not os.path.isdir(cfgDir):
+                raise CrashGenError("Invalid config dir: {}".format(cfgDir))
+            # else: good path
+        else: 
+            os.makedirs(cfgDir, exist_ok=True) # like "mkdir -p"
+        # Now we have a good cfg dir
+        cfgValues = {
+            'runDir':   self.getRunDir(),
+            'ip':       '127.0.0.1', # TODO: change to a network addressable ip
+            'port':     self._port,
+            'fepPort':  self._fepPort,
+        }
+        cfgTemplate = """
+dataDir {runDir}/data
+logDir  {runDir}/log
+
+charset UTF-8
+
+firstEp {ip}:{fepPort}
+fqdn {ip}
+serverPort {port}
+
+# was all 135 below
+dDebugFlag 135
+cDebugFlag 135
+rpcDebugFlag 135
+qDebugFlag 135
+# httpDebugFlag 143
+# asyncLog 0
+# tables 10
+maxtablesPerVnode 10
+rpcMaxTime 101
+# cache 2
+keep 36500
+# walLevel 2
+walLevel 1
+#
+# maxConnections 100
+"""
+        cfgContent = cfgTemplate.format_map(cfgValues)
+        f = open(cfgFile, "w")
+        f.write(cfgContent)
+        f.close()
+
+    def rotateLogs(self):
+        logPath = self.getLogDir()
+        # ref: https://stackoverflow.com/questions/1995373/deleting-all-files-in-a-directory-with-python/1995397
+        if os.path.exists(logPath):
+            logPathSaved = logPath + "_" + time.strftime('%Y-%m-%d-%H-%M-%S')
+            Logging.info("Saving old log files to: {}".format(logPathSaved))
+            os.rename(logPath, logPathSaved)
+        # os.mkdir(logPath) # recreate, no need actually, TDengine will auto-create with proper perms
+
+
+    def getExecFile(self): # .../taosd
+        return self._buildDir + "/build/bin/taosd"
+
+    def getRunDir(self): # TODO: rename to "root dir" ?!
+        return self._buildDir + self._subdir
+
+    def getCfgDir(self): # path, not file
+        return self.getRunDir() + "/cfg"
+
+    def getLogDir(self):
+        return self.getRunDir() + "/log"
+
+    def getHostAddr(self):
+        return "127.0.0.1"
+
+    def getServiceCmdLine(self): # to start the instance
+        return [self.getExecFile(), '-c', self.getCfgDir()] # used in subproce.Popen()
+    
+    def _getDnodes(self, dbc):
+        dbc.query("show dnodes")
+        cols = dbc.getQueryResult() #  id,end_point,vnodes,cores,status,role,create_time,offline reason
+        return {c[1]:c[4] for c in cols} # {'xxx:6030':'ready', 'xxx:6130':'ready'}
+
+    def createDnode(self, dbt: DbTarget):
+        """
+        With a connection to the "first" EP, let's create a dnode for someone else who
+        wants to join.
+        """
+        dbc = DbConn.createNative(self.getDbTarget())
+        dbc.open()
+
+        if dbt.getEp() in self._getDnodes(dbc):
+            Logging.info("Skipping DNode creation for: {}".format(dbt))
+            dbc.close()
+            return
+
+        sql = "CREATE DNODE \"{}\"".format(dbt.getEp())
+        dbc.execute(sql)
+        dbc.close()
+
+    def getStatus(self):
+        return self._smThread.getStatus()
+
+    def getSmThread(self):
+        return self._smThread
+
+    def start(self):
+        if not self.getStatus().isStopped():
+            raise CrashGenError("Cannot start instance from status: {}".format(self.getStatus()))
+
+        Logging.info("Starting TDengine instance: {}".format(self))
+        self.generateCfgFile() # service side generates config file, client does not
+        self.rotateLogs()
+
+        self._smThread.start(self.getServiceCmdLine())
+
+    def stop(self):
+        self._smThread.stop()
+
+    def isFirst(self):
+        return self._tInstNum == 0
+
+
+class TdeSubProcess:
+    """
+    A class to to represent the actual sub process that is the run-time
+    of a TDengine instance. 
+
+    It takes a TdeInstance object as its parameter, with the rationale being
+    "a sub process runs an instance".
+    """
+
+    # RET_ALREADY_STOPPED = -1
+    # RET_TIME_OUT = -3
+    # RET_SUCCESS = -4
+
+    def __init__(self):
+        self.subProcess = None
+        # if tInst is None:
+        #     raise CrashGenError("Empty instance not allowed in TdeSubProcess")
+        # self._tInst = tInst # Default create at ServiceManagerThread
+
+    def getStdOut(self):
+        return self.subProcess.stdout
+
+    def getStdErr(self):
+        return self.subProcess.stderr
+
+    def isRunning(self):
+        return self.subProcess is not None
+
+    def getPid(self):
+        return self.subProcess.pid
+
+    def start(self, cmdLine):
+        ON_POSIX = 'posix' in sys.builtin_module_names
+
+        # Sanity check
+        if self.subProcess:  # already there
+            raise RuntimeError("Corrupt process state")
+    
+        self.subProcess = subprocess.Popen(
+            cmdLine,
+            shell=False,
+            # svcCmdSingle, shell=True, # capture core dump?
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            # bufsize=1, # not supported in binary mode
+            close_fds=ON_POSIX
+            )  # had text=True, which interferred with reading EOF
+
+    def stop(self):
+        """
+        Stop a sub process, and try to return a meaningful return code.
+
+        Common POSIX signal values (from man -7 signal):
+        SIGHUP           1
+        SIGINT           2 
+        SIGQUIT          3 
+        SIGILL           4
+        SIGTRAP          5
+        SIGABRT          6 
+        SIGIOT           6 
+        SIGBUS           7 
+        SIGEMT           - 
+        SIGFPE           8  
+        SIGKILL          9  
+        SIGUSR1         10 
+        SIGSEGV         11
+        SIGUSR2         12
+        """
+        if not self.subProcess:
+            print("Sub process already stopped")
+            return  # -1
+
+        retCode = self.subProcess.poll() # ret -N means killed with signal N, otherwise it's from exit(N)
+        if retCode:  # valid return code, process ended
+            retCode = -retCode # only if valid
+            Logging.warning("TSP.stop(): process ended itself")
+            self.subProcess = None
+            return retCode
+
+        # process still alive, let's interrupt it
+        print("Terminate running process, send SIG_INT and wait...")
+        # sub process should end, then IPC queue should end, causing IO thread to end
+        self.subProcess.send_signal(signal.SIGINT)
+        self.subProcess.wait(20)
+        retCode = self.subProcess.returncode # should always be there
+        # May throw subprocess.TimeoutExpired exception above, therefore
+        # The process is guranteed to have ended by now
+        self.subProcess = None        
+        if retCode != 0: # != (- signal.SIGINT):
+            Logging.error("TSP.stop(): Failed to stop sub proc properly w/ SIG_INT, retCode={}".format(retCode))
+        else:
+            Logging.info("TSP.stop(): sub proc successfully terminated with SIG_INT")
+        return - retCode
+
+class ServiceManager:
+    PAUSE_BETWEEN_IPC_CHECK = 1.2  # seconds between checks on STDOUT of sub process
+
+    def __init__(self, numDnodes): # >1 when we run a cluster
+        Logging.info("TDengine Service Manager (TSM) created")
+        self._numDnodes = numDnodes # >1 means we have a cluster
+        self._lock = threading.Lock()
+        # signal.signal(signal.SIGTERM, self.sigIntHandler) # Moved to MainExec
+        # signal.signal(signal.SIGINT, self.sigIntHandler)
+        # signal.signal(signal.SIGUSR1, self.sigUsrHandler)  # different handler!
+
+        self.inSigHandler = False
+        # self._status = MainExec.STATUS_RUNNING # set inside
+        # _startTaosService()
+        self._runCluster = (numDnodes > 1)
+        self._tInsts : List[TdeInstance] = []
+        for i in range(0, numDnodes):
+            ti = self._createTdeInstance(i) # construct tInst
+            self._tInsts.append(ti)
+
+        # self.svcMgrThreads : List[ServiceManagerThread] = []
+        # for i in range(0, numDnodes):
+        #     thread = self._createThread(i) # construct tInst
+        #     self.svcMgrThreads.append(thread)
+
+    def _createTdeInstance(self, dnIndex):
+        if not self._runCluster: # single instance 
+            subdir = 'test'
+        else:        # Create all threads in a cluster
+            subdir = 'cluster_dnode_{}'.format(dnIndex)
+        fepPort= 6030 # firstEP Port
+        port   = fepPort + dnIndex * 100
+        return TdeInstance(subdir, dnIndex, port, fepPort)
+        # return ServiceManagerThread(dnIndex, ti)
+
+    def _doMenu(self):
+        choice = ""
+        while True:
+            print("\nInterrupting Service Program, Choose an Action: ")
+            print("1: Resume")
+            print("2: Terminate")
+            print("3: Restart")
+            # Remember to update the if range below
+            # print("Enter Choice: ", end="", flush=True)
+            while choice == "":
+                choice = input("Enter Choice: ")
+                if choice != "":
+                    break  # done with reading repeated input
+            if choice in ["1", "2", "3"]:
+                break  # we are done with whole method
+            print("Invalid choice, please try again.")
+            choice = ""  # reset
+        return choice
+
+    def sigUsrHandler(self, signalNumber, frame):
+        print("Interrupting main thread execution upon SIGUSR1")
+        if self.inSigHandler:  # already
+            print("Ignoring repeated SIG...")
+            return  # do nothing if it's already not running
+        self.inSigHandler = True
+
+        choice = self._doMenu()
+        if choice == "1":            
+            self.sigHandlerResume() # TODO: can the sub-process be blocked due to us not reading from queue?
+        elif choice == "2":
+            self.stopTaosServices()
+        elif choice == "3": # Restart
+            self.restart()
+        else:
+            raise RuntimeError("Invalid menu choice: {}".format(choice))
+
+        self.inSigHandler = False
+
+    def sigIntHandler(self, signalNumber, frame):
+        print("ServiceManager: INT Signal Handler starting...")
+        if self.inSigHandler:
+            print("Ignoring repeated SIG_INT...")
+            return
+        self.inSigHandler = True
+
+        self.stopTaosServices()
+        print("ServiceManager: INT Signal Handler returning...")
+        self.inSigHandler = False
+
+    def sigHandlerResume(self):
+        print("Resuming TDengine service manager (main thread)...\n\n")
+
+    # def _updateThreadStatus(self):
+    #     if self.svcMgrThread:  # valid svc mgr thread
+    #         if self.svcMgrThread.isStopped():  # done?
+    #             self.svcMgrThread.procIpcBatch()  # one last time. TODO: appropriate?
+    #             self.svcMgrThread = None  # no more
+
+    def isActive(self):
+        """
+        Determine if the service/cluster is active at all, i.e. at least
+        one thread is not "stopped".
+        """
+        for ti in self._tInsts:
+            if not ti.getStatus().isStopped():
+                return True
+        return False
+
+    # def isRestarting(self):
+    #     """
+    #     Determine if the service/cluster is being "restarted", i.e., at least
+    #     one thread is in "restarting" status
+    #     """
+    #     for thread in self.svcMgrThreads:
+    #         if thread.isRestarting():
+    #             return True
+    #     return False
+
+    def isStable(self):
+        """
+        Determine if the service/cluster is "stable", i.e. all of the
+        threads are in "stable" status.
+        """
+        for ti in self._tInsts:
+            if not ti.getStatus().isStable():
+                return False
+        return True
+
+    def _procIpcAll(self):
+        while self.isActive():
+            Progress.emit(Progress.SERVICE_HEART_BEAT)
+            for ti in self._tInsts: # all thread objects should always be valid
+            # while self.isRunning() or self.isRestarting() :  # for as long as the svc mgr thread is still here
+                status = ti.getStatus()
+                if  status.isRunning():
+                    th = ti.getSmThread()
+                    th.procIpcBatch()  # regular processing,
+                    if  status.isStopped():
+                        th.procIpcBatch() # one last time?
+                    # self._updateThreadStatus()
+                    
+            time.sleep(self.PAUSE_BETWEEN_IPC_CHECK)  # pause, before next round
+        # raise CrashGenError("dummy")
+        print("Service Manager Thread (with subprocess) ended, main thread exiting...")
+
+    def _getFirstInstance(self):
+        return self._tInsts[0]
+
+    def startTaosServices(self):
+        with self._lock:
+            if self.isActive():
+                raise RuntimeError("Cannot start TAOS service(s) when one/some may already be running")
+
+            # Find if there's already a taosd service, and then kill it
+            for proc in psutil.process_iter():
+                if proc.name() == 'taosd':
+                    print("Killing an existing TAOSD process in 2 seconds... press CTRL-C to interrupt")
+                    time.sleep(2.0)
+                    proc.kill()
+                # print("Process: {}".format(proc.name()))
+            
+            # self.svcMgrThread = ServiceManagerThread()  # create the object
+            
+            for ti in self._tInsts:
+                ti.start()  
+                if not ti.isFirst():                                    
+                    tFirst = self._getFirstInstance()
+                    tFirst.createDnode(ti.getDbTarget())
+                ti.getSmThread().procIpcBatch(trimToTarget=10, forceOutput=True)  # for printing 10 lines                                     
+
+    def stopTaosServices(self):
+        with self._lock:
+            if not self.isActive():
+                Logging.warning("Cannot stop TAOS service(s), already not active")
+                return
+
+            for ti in self._tInsts:
+                ti.stop()
+                
+    def run(self):
+        self.startTaosServices()
+        self._procIpcAll()  # pump/process all the messages, may encounter SIG + restart
+        if  self.isActive():  # if sig handler hasn't destroyed it by now
+            self.stopTaosServices()  # should have started already
+
+    def restart(self):
+        if not self.isStable():
+            Logging.warning("Cannot restart service/cluster, when not stable")
+            return
+
+        # self._isRestarting = True
+        if  self.isActive():
+            self.stopTaosServices()
+        else:
+            Logging.warning("Service not active when restart requested")
+
+        self.startTaosServices()
+        # self._isRestarting = False
+
+    # def isRunning(self):
+    #     return self.svcMgrThread != None
+
+    # def isRestarting(self):
+    #     return self._isRestarting
+
+class ServiceManagerThread:
+    """
+    A class representing a dedicated thread which manages the "sub process"
+    of the TDengine service, interacting with its STDOUT/ERR.
+
+    It takes a TdeInstance parameter at creation time, or create a default    
+    """
+    MAX_QUEUE_SIZE = 10000
+
+    def __init__(self):
+        # Set the sub process
+        self._tdeSubProcess = None # type: TdeSubProcess
+
+        # Arrange the TDengine instance
+        # self._tInstNum = tInstNum # instance serial number in cluster, ZERO based
+        # self._tInst    = tInst or TdeInstance() # Need an instance
+
+        self._thread = None # The actual thread, # type: threading.Thread
+        self._status = Status(Status.STATUS_STOPPED) # The status of the underlying service, actually.
+
+    def __repr__(self):
+        return "[SvcMgrThread: status={}, subProc={}]".format(
+            self.getStatus(), self._tdeSubProcess)
+
+    def getStatus(self):
+        return self._status
+
+    # Start the thread (with sub process), and wait for the sub service
+    # to become fully operational
+    def start(self, cmdLine):
+        if self._thread:
+            raise RuntimeError("Unexpected _thread")
+        if self._tdeSubProcess:
+            raise RuntimeError("TDengine sub process already created/running")
+
+        Logging.info("Attempting to start TAOS service: {}".format(self))
+
+        self._status.set(Status.STATUS_STARTING)
+        self._tdeSubProcess = TdeSubProcess()
+        self._tdeSubProcess.start(cmdLine)
+
+        self._ipcQueue = Queue()
+        self._thread = threading.Thread( # First thread captures server OUTPUT
+            target=self.svcOutputReader,
+            args=(self._tdeSubProcess.getStdOut(), self._ipcQueue))
+        self._thread.daemon = True  # thread dies with the program
+        self._thread.start()
+
+        self._thread2 = threading.Thread( # 2nd thread captures server ERRORs
+            target=self.svcErrorReader,
+            args=(self._tdeSubProcess.getStdErr(), self._ipcQueue))
+        self._thread2.daemon = True  # thread dies with the program
+        self._thread2.start()
+
+        # wait for service to start
+        for i in range(0, 100):
+            time.sleep(1.0)
+            # self.procIpcBatch() # don't pump message during start up
+            print("_zz_", end="", flush=True)
+            if self._status.isRunning():
+                Logging.info("[] TDengine service READY to process requests")
+                Logging.info("[] TAOS service started: {}".format(self))
+                # self._verifyDnode(self._tInst) # query and ensure dnode is ready
+                # Logging.debug("[] TAOS Dnode verified: {}".format(self))
+                return  # now we've started
+        # TODO: handle failure-to-start  better?
+        self.procIpcBatch(100, True) # display output before cronking out, trim to last 20 msgs, force output
+        raise RuntimeError("TDengine service did not start successfully: {}".format(self))
+
+    def _verifyDnode(self, tInst: TdeInstance):
+        dbc = DbConn.createNative(tInst.getDbTarget())
+        dbc.open()
+        dbc.query("show dnodes")
+        # dbc.query("DESCRIBE {}.{}".format(dbName, self._stName))
+        cols = dbc.getQueryResult() #  id,end_point,vnodes,cores,status,role,create_time,offline reason
+        # ret = {row[0]:row[1] for row in stCols if row[3]=='TAG'} # name:type
+        isValid = False
+        for col in cols:
+            # print("col = {}".format(col))
+            ep = col[1].split(':') # 10.1.30.2:6030
+            print("Found ep={}".format(ep))
+            if tInst.getPort() == int(ep[1]): # That's us
+                # print("Valid Dnode matched!")
+                isValid = True # now we are valid
+                break
+        if not isValid:
+            print("Failed to start dnode, sleep for a while")
+            time.sleep(600)
+            raise RuntimeError("Failed to start Dnode, expected port not found: {}".
+                format(tInst.getPort()))
+        dbc.close()
+
+    def stop(self):
+        # can be called from both main thread or signal handler
+        print("Terminating TDengine service running as the sub process...")
+        if self.getStatus().isStopped():
+            print("Service already stopped")
+            return
+        if self.getStatus().isStopping():
+            print("Service is already being stopped")
+            return
+        # Linux will send Control-C generated SIGINT to the TDengine process
+        # already, ref:
+        # https://unix.stackexchange.com/questions/176235/fork-and-how-signals-are-delivered-to-processes
+        if not self._tdeSubProcess:
+            raise RuntimeError("sub process object missing")
+
+        self._status.set(Status.STATUS_STOPPING)
+        # retCode = self._tdeSubProcess.stop()
+        try:
+            retCode = self._tdeSubProcess.stop()
+            # print("Attempted to stop sub process, got return code: {}".format(retCode))
+            if retCode == signal.SIGSEGV : # SGV
+                Logging.error("[[--ERROR--]]: TDengine service SEGV fault (check core file!)")
+        except subprocess.TimeoutExpired as err:
+            print("Time out waiting for TDengine service process to exit")
+        else:    
+            if self._tdeSubProcess.isRunning():  # still running, should now never happen
+                print("FAILED to stop sub process, it is still running... pid = {}".format(
+                    self._tdeSubProcess.getPid()))
+            else:
+                self._tdeSubProcess = None  # not running any more
+                self.join()  # stop the thread, change the status, etc.
+
+        # Check if it's really stopped
+        outputLines = 10 # for last output
+        if  self.getStatus().isStopped():
+            self.procIpcBatch(outputLines)  # one last time
+            Logging.debug("End of TDengine Service Output: {}".format(self))
+            Logging.info("----- TDengine Service (managed by SMT) is now terminated -----\n")
+        else:
+            print("WARNING: SMT did not terminate as expected: {}".format(self))
+
+    def join(self):
+        # TODO: sanity check
+        if not self.getStatus().isStopping():
+            raise RuntimeError(
+                "SMT.Join(): Unexpected status: {}".format(self._status))
+
+        if self._thread:
+            self._thread.join()
+            self._thread = None
+            self._status.set(Status.STATUS_STOPPED)
+            # STD ERR thread
+            self._thread2.join()
+            self._thread2 = None
+        else:
+            print("Joining empty thread, doing nothing")
+
+    def _trimQueue(self, targetSize):
+        if targetSize <= 0:
+            return  # do nothing
+        q = self._ipcQueue
+        if (q.qsize() <= targetSize):  # no need to trim
+            return
+
+        Logging.debug("Triming IPC queue to target size: {}".format(targetSize))
+        itemsToTrim = q.qsize() - targetSize
+        for i in range(0, itemsToTrim):
+            try:
+                q.get_nowait()
+            except Empty:
+                break  # break out of for loop, no more trimming
+
+    TD_READY_MSG = "TDengine is initialized successfully"
+
+    def procIpcBatch(self, trimToTarget=0, forceOutput=False):
+        self._trimQueue(trimToTarget)  # trim if necessary
+        # Process all the output generated by the underlying sub process,
+        # managed by IO thread
+        print("<", end="", flush=True)
+        while True:
+            try:
+                line = self._ipcQueue.get_nowait()  # getting output at fast speed
+                self._printProgress("_o")
+            except Empty:
+                # time.sleep(2.3) # wait only if there's no output
+                # no more output
+                print(".>", end="", flush=True)
+                return  # we are done with THIS BATCH
+            else:  # got line, printing out
+                if forceOutput:
+                    Logging.info(line)
+                else:
+                    Logging.debug(line)
+        print(">", end="", flush=True)
+
+    _ProgressBars = ["--", "//", "||", "\\\\"]
+
+    def _printProgress(self, msg):  # TODO: assuming 2 chars
+        print(msg, end="", flush=True)
+        pBar = self._ProgressBars[Dice.throw(4)]
+        print(pBar, end="", flush=True)
+        print('\b\b\b\b', end="", flush=True)
+
+    def svcOutputReader(self, out: IO, queue):
+        # Important Reference: https://stackoverflow.com/questions/375427/non-blocking-read-on-a-subprocess-pipe-in-python
+        # print("This is the svcOutput Reader...")
+        # for line in out :
+        for line in iter(out.readline, b''):
+            # print("Finished reading a line: {}".format(line))
+            # print("Adding item to queue...")
+            try:
+                line = line.decode("utf-8").rstrip()
+            except UnicodeError:
+                print("\nNon-UTF8 server output: {}\n".format(line))
+
+            # This might block, and then causing "out" buffer to block
+            queue.put(line)
+            self._printProgress("_i")
+
+            if self._status.isStarting():  # we are starting, let's see if we have started
+                if line.find(self.TD_READY_MSG) != -1:  # found
+                    Logging.info("Waiting for the service to become FULLY READY")
+                    time.sleep(1.0) # wait for the server to truly start. TODO: remove this
+                    Logging.info("Service is now FULLY READY") # TODO: more ID info here?
+                    self._status.set(Status.STATUS_RUNNING)
+
+            # Trim the queue if necessary: TODO: try this 1 out of 10 times
+            self._trimQueue(self.MAX_QUEUE_SIZE * 9 // 10)  # trim to 90% size
+
+            if self._status.isStopping():  # TODO: use thread status instead
+                # WAITING for stopping sub process to finish its outptu
+                print("_w", end="", flush=True)
+
+            # queue.put(line)
+        # meaning sub process must have died
+        Logging.info("\nEnd of stream detected for TDengine STDOUT: {}".format(self))
+        out.close()
+
+    def svcErrorReader(self, err: IO, queue):
+        for line in iter(err.readline, b''):
+            print("\nTDengine Service (taosd) ERROR (from stderr): {}".format(line))
+        Logging.info("\nEnd of stream detected for TDengine STDERR: {}".format(self))
+        err.close()
--- a/tests/pytest/crash_gen_bootstrap.py
+++ b/tests/pytest/crash_gen_bootstrap.py
@ -0,0 +1,23 @@
+# -----!/usr/bin/python3.7
+###################################################################
+#           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
+#
+###################################################################
+
+import sys
+from crash_gen.crash_gen import MainExec
+
+if __name__ == "__main__":
+    
+    mExec = MainExec()
+    mExec.init()
+    exitCode = mExec.run()
+
+    print("Exiting with code: {}".format(exitCode))
+    sys.exit(exitCode)
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@ -18,7 +18,9 @@ python3 ./test.py -f insert/multi.py
 python3 ./test.py -f insert/randomNullCommit.py
 python3 insert/retentionpolicy.py
 python3 ./test.py -f insert/alterTableAndInsert.py
+python3 ./test.py -f insert/insertIntoTwoTables.py

+python3 ./test.py -f table/alter_wal0.py
 python3 ./test.py -f table/column_name.py
 python3 ./test.py -f table/column_num.py
 python3 ./test.py -f table/db_table.py
--- a/tests/pytest/insert/insertIntoTwoTables.py
+++ b/tests/pytest/insert/insertIntoTwoTables.py
@ -0,0 +1,53 @@
+###################################################################
+#           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
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+    def run(self):
+        tdSql.prepare()
+                
+        ### test case for TD-1758 ###
+        print("==============step1")
+        tdSql.execute(
+            "create table t0(ts timestamp, c int)")
+        tdSql.execute(
+            'create table t1(ts timestamp, c binary(1))')
+        tdSql.execute(
+            "insert into t0 values(now,1) t1 values(now,'0')(now+1a,'1')(now+2a,'2')(now+3a,'3')(now+4a,'4')")
+
+        print("==============step2")
+
+        tdSql.query("select * from t0")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 1, 1)
+
+        tdSql.query("select * from t1")
+        tdSql.checkRows(5)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
--- a/tests/pytest/query/querySort.py
+++ b/tests/pytest/query/querySort.py
@ -96,6 +96,12 @@ class TDTestCase:
        tdSql.query("select * from st order by ts desc")
        self.checkColumnSorted(0, "desc")

+        print("======= step 2: verify order for special column =========")
+        
+        tdSql.query("select tbcol1 from st order by ts desc")
+
+        tdSql.query("select tbcol6 from st order by ts desc")
+
        for i in range(1, 10):
            tdSql.error("select * from st order by tbcol%d" % i)
            tdSql.error("select * from st order by tbcol%d asc" % i)
--- a/tests/pytest/tag_lite/datatype.py
+++ b/tests/pytest/tag_lite/datatype.py
@ -103,7 +103,7 @@ class TDTestCase:
        tdSql.execute('alter table stb add tag tnc nchar(10)')
        for tid in range(1, self.ntables + 1):
            tdSql.execute('alter table tb%d set tag tnc=\"%s\"' %
-                          (tid, str(tid * 1.2)))
+                          (tid, str(tid + 1000000000)))
        tdLog.info("insert %d data in to each %d tables" % (2, self.ntables))
        for rid in range(self.rowsPerTable + 1, self.rowsPerTable + 3):
            sqlcmd = ['insert into']
--- a/tests/script/general/insert/insert_drop.sim
+++ b/tests/script/general/insert/insert_drop.sim
@ -52,10 +52,10 @@ sleep 1000

 sql use $db
 sql drop table tb5
-
+$i = 0
 while $i < 4
-  $tbId = $i + $halfNum
-  $tb = $tbPrefix . $i
+  
+  $tb = tb . $i
  $x = 0
  while $x < $rowNum
    $xs = $x * $delta