diff --git a/include/common/tmsgdef.h b/include/common/tmsgdef.h
index d6071ebcf3..592672b32b 100644
--- a/include/common/tmsgdef.h
+++ b/include/common/tmsgdef.h
@@ -159,6 +159,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_VND_MQ_QUERY, "vnode-mq-query", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_VND_MQ_CONNECT, "vnode-mq-connect", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_VND_MQ_DISCONNECT, "vnode-mq-disconnect", NULL, NULL)
+  TD_DEF_MSG_TYPE(TDMT_VND_MQ_SET_CONN, "vnode-mq-set-conn", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_VND_MQ_SET_CUR, "vnode-mq-set-cur", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_VND_RES_READY, "vnode-res-ready", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_VND_TASKS_STATUS, "vnode-tasks-status", NULL, NULL)
diff --git a/include/util/taoserror.h b/include/util/taoserror.h
index ae36ac7216..a10dd8eda2 100644
--- a/include/util/taoserror.h
+++ b/include/util/taoserror.h
@@ -400,6 +400,8 @@ int32_t* taosGetErrno();
 #define TSDB_CODE_WAL_APP_ERROR                 TAOS_DEF_ERROR_CODE(0, 0x1000)  //"Unexpected generic error in wal")
 #define TSDB_CODE_WAL_FILE_CORRUPTED            TAOS_DEF_ERROR_CODE(0, 0x1001)  //"WAL file is corrupted")
 #define TSDB_CODE_WAL_SIZE_LIMIT                TAOS_DEF_ERROR_CODE(0, 0x1002)  //"WAL size exceeds limit")
+#define TSDB_CODE_WAL_INVALID_VER               TAOS_DEF_ERROR_CODE(0, 0x1003)  //"WAL invalid version")
+#define TSDB_CODE_WAL_OUT_OF_MEMORY             TAOS_DEF_ERROR_CODE(0, 0x1004)  //"WAL out of memory")
 
 // tfs
 #define TSDB_CODE_FS_OUT_OF_MEMORY              TAOS_DEF_ERROR_CODE(0, 0x2200)  //"tfs out of memory")
diff --git a/source/dnode/mnode/impl/inc/mndConsumer.h b/source/dnode/mnode/impl/inc/mndConsumer.h
index 60f186d7d2..68ba08b66e 100644
--- a/source/dnode/mnode/impl/inc/mndConsumer.h
+++ b/source/dnode/mnode/impl/inc/mndConsumer.h
@@ -25,11 +25,8 @@ extern "C" {
 int32_t mndInitConsumer(SMnode *pMnode);
 void    mndCleanupConsumer(SMnode *pMnode);
 
-SConsumerObj *mndAcquireConsumer(SMnode *pMnode, int32_t consumerId);
-void          mndReleaseConsumer(SMnode *pMnode, SConsumerObj *pConsumer);
-
-SCGroupObj *mndAcquireCGroup(SMnode *pMnode, char *consumerGroup);
-void        mndReleaseCGroup(SMnode *pMnode, SCGroupObj *pCGroup);
+SMqConsumerObj *mndAcquireConsumer(SMnode *pMnode, int32_t consumerId);
+void            mndReleaseConsumer(SMnode *pMnode, SMqConsumerObj *pConsumer);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/mnode/impl/inc/mndDef.h b/source/dnode/mnode/impl/inc/mndDef.h
index 1af9b840a9..b490eeac96 100644
--- a/source/dnode/mnode/impl/inc/mndDef.h
+++ b/source/dnode/mnode/impl/inc/mndDef.h
@@ -302,6 +302,7 @@ typedef struct {
   char    payload[];
 } SShowObj;
 
+#if 0
 typedef struct SConsumerObj {
   uint64_t uid;
   int64_t  createTime;
@@ -309,17 +310,59 @@ typedef struct SConsumerObj {
   //uint64_t dbUid;
   int32_t  version;
   SRWLatch lock;
-  SList*   topics;
+  SArray*   topics;
 } SConsumerObj;
 
+typedef struct SMqTopicConsumer {
+  int64_t consumerId;
+  SList*  topicList;
+} SMqTopicConsumer;
+#endif
+
+typedef struct SMqCGroup {
+  char    name[TSDB_CONSUMER_GROUP_LEN];
+  int32_t status;       // 0 - uninitialized, 1 - wait rebalance, 2- normal
+  SList  *consumerIds;  // SList<int64_t>
+  SList  *idleVGroups;  // SList<int32_t>
+} SMqCGroup;
+
+typedef struct SMqTopicObj {
+  char      name[TSDB_TOPIC_FNAME_LEN];
+  char      db[TSDB_DB_FNAME_LEN];
+  int64_t   createTime;
+  int64_t   updateTime;
+  uint64_t  uid;
+  uint64_t  dbUid;
+  int32_t   version;
+  SRWLatch  lock;
+  int32_t   sqlLen;
+  char     *sql;
+  char     *logicalPlan;
+  char     *physicalPlan;
+  SHashObj *cgroups;  // SHashObj<SMqCGroup>
+} SMqTopicObj;
+
+// TODO: add cache and change name to id
+typedef struct SMqConsumerTopic {
+  char   name[TSDB_TOPIC_FNAME_LEN];
+  SList *vgroups;  // SList<int32_t>
+} SMqConsumerTopic;
+
+typedef struct SMqConsumerObj {
+  SRWLatch lock;
+  int64_t  consumerId;
+  char     cgroup[TSDB_CONSUMER_GROUP_LEN];
+  SArray  *topics;  // SArray<SMqConsumerTopic>
+} SMqConsumerObj;
+
 typedef struct SMqSubConsumerObj {
   int64_t consumerUid;  // if -1, unassigned
-  SList*   vgId;        //SList<int32_t>
+  SList  *vgId;         // SList<int32_t>
 } SMqSubConsumerObj;
 
 typedef struct SMqSubCGroupObj {
   char   name[TSDB_CONSUMER_GROUP_LEN];
-  SList* consumers;     //SList<SMqConsumerObj>
+  SList *consumers;  // SList<SMqConsumerObj>
 } SMqSubCGroupObj;
 
 typedef struct SMqSubTopicObj {
@@ -332,32 +375,33 @@ typedef struct SMqSubTopicObj {
   int32_t  version;
   SRWLatch lock;
   int32_t  sqlLen;
-  char*    sql;
-  char*    logicalPlan;
-  char*    physicalPlan;
-  SList*   cgroups;     //SList<SMqSubCGroupObj>
+  char    *sql;
+  char    *logicalPlan;
+  char    *physicalPlan;
+  SList   *cgroups;  // SList<SMqSubCGroupObj>
 } SMqSubTopicObj;
 
 typedef struct SMqConsumerSubObj {
   int64_t topicUid;
-  SList*  vgIds;        //SList<int64_t>
+  SList  *vgIds;  // SList<int64_t>
 } SMqConsumerSubObj;
 
 typedef struct SMqConsumerHbObj {
   int64_t consumerId;
-  SList*  consumerSubs; //SList<SMqConsumerSubObj>
+  SList  *consumerSubs;  // SList<SMqConsumerSubObj>
 } SMqConsumerHbObj;
 
 typedef struct SMqVGroupSubObj {
   int64_t topicUid;
-  SList*  consumerIds;  //SList<int64_t>
+  SList  *consumerIds;  // SList<int64_t>
 } SMqVGroupSubObj;
 
 typedef struct SMqVGroupHbObj {
   int64_t vgId;
-  SList*  vgSubs;       //SList<SMqVGroupSubObj>
+  SList  *vgSubs;  // SList<SMqVGroupSubObj>
 } SMqVGroupHbObj;
 
+#if 0
 typedef struct SCGroupObj {
   char     name[TSDB_TOPIC_FNAME_LEN];
   int64_t  createTime;
@@ -368,24 +412,7 @@ typedef struct SCGroupObj {
   SRWLatch lock;
   SList*   consumerIds;
 } SCGroupObj;
-
-typedef struct {
-  char     name[TSDB_TOPIC_FNAME_LEN];
-  char     db[TSDB_DB_FNAME_LEN];
-  int64_t  createTime;
-  int64_t  updateTime;
-  uint64_t uid;
-  uint64_t dbUid;
-  int32_t  version;
-  SRWLatch lock;
-  int32_t  execLen;
-  void*    executor;
-  int32_t  sqlLen;
-  char*    sql;
-  char*    logicalPlan;
-  char*    physicalPlan;
-  SList*   consumerIds; 
-} STopicObj;
+#endif
 
 typedef struct SMnodeMsg {
   char    user[TSDB_USER_LEN];
diff --git a/source/dnode/mnode/impl/inc/mndTopic.h b/source/dnode/mnode/impl/inc/mndTopic.h
index d092f47d4b..fd82c60d37 100644
--- a/source/dnode/mnode/impl/inc/mndTopic.h
+++ b/source/dnode/mnode/impl/inc/mndTopic.h
@@ -25,8 +25,11 @@ extern "C" {
 int32_t mndInitTopic(SMnode *pMnode);
 void    mndCleanupTopic(SMnode *pMnode);
 
-STopicObj *mndAcquireTopic(SMnode *pMnode, char *topicName);
-void       mndReleaseTopic(SMnode *pMnode, STopicObj *pTopic);
+SMqTopicObj *mndAcquireTopic(SMnode *pMnode, char *topicName);
+void         mndReleaseTopic(SMnode *pMnode, SMqTopicObj *pTopic);
+
+SSdbRaw *mndTopicActionEncode(SMqTopicObj *pTopic);
+SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/mnode/impl/src/mndConsumer.c b/source/dnode/mnode/impl/src/mndConsumer.c
index 5391b0f73e..eeb011c084 100644
--- a/source/dnode/mnode/impl/src/mndConsumer.c
+++ b/source/dnode/mnode/impl/src/mndConsumer.c
@@ -24,16 +24,17 @@
 #include "mndTrans.h"
 #include "mndUser.h"
 #include "mndVgroup.h"
+#include "tcompare.h"
 #include "tname.h"
 
 #define MND_CONSUMER_VER_NUMBER 1
 #define MND_CONSUMER_RESERVE_SIZE 64
 
-static SSdbRaw *mndConsumerActionEncode(SConsumerObj *pConsumer);
+static SSdbRaw *mndConsumerActionEncode(SMqConsumerObj *pConsumer);
 static SSdbRow *mndConsumerActionDecode(SSdbRaw *pRaw);
-static int32_t  mndConsumerActionInsert(SSdb *pSdb, SConsumerObj *pConsumer);
-static int32_t  mndConsumerActionDelete(SSdb *pSdb, SConsumerObj *pConsumer);
-static int32_t  mndConsumerActionUpdate(SSdb *pSdb, SConsumerObj *pConsumer, SConsumerObj *pNewConsumer);
+static int32_t  mndConsumerActionInsert(SSdb *pSdb, SMqConsumerObj *pConsumer);
+static int32_t  mndConsumerActionDelete(SSdb *pSdb, SMqConsumerObj *pConsumer);
+static int32_t  mndConsumerActionUpdate(SSdb *pSdb, SMqConsumerObj *pConsumer, SMqConsumerObj *pNewConsumer);
 static int32_t  mndProcessCreateConsumerMsg(SMnodeMsg *pMsg);
 static int32_t  mndProcessDropConsumerMsg(SMnodeMsg *pMsg);
 static int32_t  mndProcessDropConsumerInRsp(SMnodeMsg *pMsg);
@@ -57,8 +58,8 @@ int32_t mndInitConsumer(SMnode *pMnode) {
                      .deleteFp = (SdbDeleteFp)mndConsumerActionDelete};
 
   mndSetMsgHandle(pMnode, TDMT_MND_SUBSCRIBE, mndProcessSubscribeReq);
-  mndSetMsgHandle(pMnode, TDMT_MND_SUBSCRIBE_RSP, mndProcessSubscribeRsp);
-  mndSetMsgHandle(pMnode, TDMT_VND_SUBSCRIBE, mndProcessSubscribeInternalReq);
+  /*mndSetMsgHandle(pMnode, TDMT_MND_SUBSCRIBE_RSP, mndProcessSubscribeRsp);*/
+  /*mndSetMsgHandle(pMnode, TDMT_VND_SUBSCRIBE, mndProcessSubscribeInternalReq);*/
   mndSetMsgHandle(pMnode, TDMT_VND_SUBSCRIBE_RSP, mndProcessSubscribeInternalRsp);
 
   return sdbSetTable(pMnode->pSdb, table);
@@ -66,85 +67,41 @@ int32_t mndInitConsumer(SMnode *pMnode) {
 
 void mndCleanupConsumer(SMnode *pMnode) {}
 
-static SSdbRaw *mndCGroupActionEncode(SCGroupObj *pCGroup) {
-  int32_t  size = sizeof(SConsumerObj) + MND_CONSUMER_RESERVE_SIZE;
+static void *mndBuildMqVGroupSetReq(SMnode *pMnode, char *topicName, int32_t vgId, int64_t consumerId, char *cgroup) {
+  return 0;
+}
+
+static SSdbRaw *mndConsumerActionEncode(SMqConsumerObj *pConsumer) {
+  int32_t  size = sizeof(SMqConsumerObj) + MND_CONSUMER_RESERVE_SIZE;
   SSdbRaw *pRaw = sdbAllocRaw(SDB_CONSUMER, MND_CONSUMER_VER_NUMBER, size);
   if (pRaw == NULL) return NULL;
 
   int32_t dataPos = 0;
-  SDB_SET_BINARY(pRaw, dataPos, pCGroup->name, TSDB_TABLE_FNAME_LEN);
-  SDB_SET_INT64(pRaw, dataPos, pCGroup->createTime);
-  SDB_SET_INT64(pRaw, dataPos, pCGroup->updateTime);
-  SDB_SET_INT64(pRaw, dataPos, pCGroup->uid);
-  /*SDB_SET_INT64(pRaw, dataPos, pConsumer->dbUid);*/
-  SDB_SET_INT32(pRaw, dataPos, pCGroup->version);
-
-  int32_t sz = listNEles(pCGroup->consumerIds);
-  SDB_SET_INT32(pRaw, dataPos, sz);
-
-  SListIter iter;
-  tdListInitIter(pCGroup->consumerIds, &iter, TD_LIST_FORWARD);
-  SListNode *pn = NULL;
-  while ((pn = tdListNext(&iter)) != NULL) {
-    int64_t consumerId = *(int64_t *)pn->data;
-    SDB_SET_INT64(pRaw, dataPos, consumerId);
+  int32_t topicNum = taosArrayGetSize(pConsumer->topics);
+  SDB_SET_INT64(pRaw, dataPos, pConsumer->consumerId);
+  int32_t len = strlen(pConsumer->cgroup);
+  SDB_SET_INT32(pRaw, dataPos, len);
+  SDB_SET_BINARY(pRaw, dataPos, pConsumer->cgroup, len);
+  SDB_SET_INT32(pRaw, dataPos, topicNum);
+  for (int i = 0; i < topicNum; i++) {
+    int32_t           len;
+    SMqConsumerTopic *pConsumerTopic = taosArrayGet(pConsumer->topics, i);
+    len = strlen(pConsumerTopic->name);
+    SDB_SET_INT32(pRaw, dataPos, len);
+    SDB_SET_BINARY(pRaw, dataPos, pConsumerTopic->name, len);
+    int vgSize;
+    if (pConsumerTopic->vgroups == NULL) {
+      vgSize = 0;
+    } else {
+      vgSize = listNEles(pConsumerTopic->vgroups);
+    }
+    SDB_SET_INT32(pRaw, dataPos, vgSize);
+    for (int j = 0; j < vgSize; j++) {
+      // SList* head;
+      /*SDB_SET_INT64(pRaw, dataPos, 0[> change to list item <]);*/
+    }
   }
 
-  SDB_SET_RESERVE(pRaw, dataPos, MND_CONSUMER_RESERVE_SIZE);
-  SDB_SET_DATALEN(pRaw, dataPos);
-  return pRaw;
-}
-
-static SSdbRow *mndCGroupActionDecode(SSdbRaw *pRaw) {
-  int8_t sver = 0;
-  if (sdbGetRawSoftVer(pRaw, &sver) != 0) return NULL;
-
-  if (sver != MND_CONSUMER_VER_NUMBER) {
-    terrno = TSDB_CODE_SDB_INVALID_DATA_VER;
-    mError("failed to decode cgroup since %s", terrstr());
-    return NULL;
-  }
-
-  // TODO: maximum size is not known
-  int32_t     size = sizeof(SCGroupObj) + 128 * sizeof(int64_t);
-  SSdbRow    *pRow = sdbAllocRow(size);
-  SCGroupObj *pCGroup = sdbGetRowObj(pRow);
-  if (pCGroup == NULL) return NULL;
-
-  int32_t dataPos = 0;
-  SDB_GET_BINARY(pRaw, pRow, dataPos, pCGroup->name, TSDB_TABLE_FNAME_LEN);
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pCGroup->createTime);
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pCGroup->updateTime);
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pCGroup->uid);
-  /*SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->dbUid);*/
-  SDB_GET_INT32(pRaw, pRow, dataPos, &pCGroup->version);
-
-  int32_t sz;
-  SDB_GET_INT32(pRaw, pRow, dataPos, &sz);
-  // TODO: free list when failing
-  tdListInit(pCGroup->consumerIds, sizeof(int64_t));
-  for (int i = 0; i < sz; i++) {
-    int64_t consumerId;
-    SDB_GET_INT64(pRaw, pRow, dataPos, &consumerId);
-    tdListAppend(pCGroup->consumerIds, &consumerId);
-  }
-
-  SDB_GET_RESERVE(pRaw, pRow, dataPos, MND_CONSUMER_RESERVE_SIZE);
-  return pRow;
-}
-
-static SSdbRaw *mndConsumerActionEncode(SConsumerObj *pConsumer) {
-  int32_t  size = sizeof(SConsumerObj) + MND_CONSUMER_RESERVE_SIZE;
-  SSdbRaw *pRaw = sdbAllocRaw(SDB_CONSUMER, MND_CONSUMER_VER_NUMBER, size);
-  if (pRaw == NULL) return NULL;
-
-  int32_t dataPos = 0;
-  SDB_SET_INT64(pRaw, dataPos, pConsumer->uid);
-  SDB_SET_INT64(pRaw, dataPos, pConsumer->createTime);
-  SDB_SET_INT64(pRaw, dataPos, pConsumer->updateTime);
-  /*SDB_SET_INT64(pRaw, dataPos, pConsumer->dbUid);*/
-  SDB_SET_INT32(pRaw, dataPos, pConsumer->version);
-
   SDB_SET_RESERVE(pRaw, dataPos, MND_CONSUMER_RESERVE_SIZE);
   SDB_SET_DATALEN(pRaw, dataPos);
 
@@ -161,56 +118,67 @@ static SSdbRow *mndConsumerActionDecode(SSdbRaw *pRaw) {
     return NULL;
   }
 
-  int32_t       size = sizeof(SConsumerObj) + TSDB_MAX_COLUMNS * sizeof(SSchema);
-  SSdbRow      *pRow = sdbAllocRow(size);
-  SConsumerObj *pConsumer = sdbGetRowObj(pRow);
+  int32_t         size = sizeof(SMqConsumerObj);
+  SSdbRow        *pRow = sdbAllocRow(size);
+  SMqConsumerObj *pConsumer = sdbGetRowObj(pRow);
   if (pConsumer == NULL) return NULL;
 
   int32_t dataPos = 0;
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->uid);
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->createTime);
-  SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->updateTime);
-  /*SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->dbUid);*/
-  SDB_GET_INT32(pRaw, pRow, dataPos, &pConsumer->version);
+  SDB_GET_INT64(pRaw, pRow, dataPos, &pConsumer->consumerId);
+  int32_t len, topicNum;
+  SDB_GET_INT32(pRaw, pRow, dataPos, &len);
+  SDB_GET_BINARY(pRaw, pRow, dataPos, pConsumer->cgroup, len);
+  SDB_GET_INT32(pRaw, pRow, dataPos, &topicNum);
+  for (int i = 0; i < topicNum; i++) {
+    int32_t           topicLen;
+    SMqConsumerTopic *pConsumerTopic = malloc(sizeof(SMqConsumerTopic));
+    if (pConsumerTopic == NULL) {
+      terrno = TSDB_CODE_OUT_OF_MEMORY;
+      // TODO
+      return NULL;
+    }
+    /*pConsumerTopic->vgroups = taosArrayInit(topicNum, sizeof(SMqConsumerTopic));*/
+    SDB_GET_INT32(pRaw, pRow, dataPos, &topicLen);
+    SDB_GET_BINARY(pRaw, pRow, dataPos, pConsumerTopic->name, topicLen);
+    int32_t vgSize;
+    SDB_GET_INT32(pRaw, pRow, dataPos, &vgSize);
+  }
 
   SDB_GET_RESERVE(pRaw, pRow, dataPos, MND_CONSUMER_RESERVE_SIZE);
 
   return pRow;
 }
 
-static int32_t mndConsumerActionInsert(SSdb *pSdb, SConsumerObj *pConsumer) {
-  mTrace("consumer:%ld, perform insert action", pConsumer->uid);
+static int32_t mndConsumerActionInsert(SSdb *pSdb, SMqConsumerObj *pConsumer) {
+  mTrace("consumer:%ld, perform insert action", pConsumer->consumerId);
   return 0;
 }
 
-static int32_t mndConsumerActionDelete(SSdb *pSdb, SConsumerObj *pConsumer) {
-  mTrace("consumer:%ld, perform delete action", pConsumer->uid);
+static int32_t mndConsumerActionDelete(SSdb *pSdb, SMqConsumerObj *pConsumer) {
+  mTrace("consumer:%ld, perform delete action", pConsumer->consumerId);
   return 0;
 }
 
-static int32_t mndConsumerActionUpdate(SSdb *pSdb, SConsumerObj *pOldConsumer, SConsumerObj *pNewConsumer) {
-  mTrace("consumer:%ld, perform update action", pOldConsumer->uid);
-  atomic_exchange_32(&pOldConsumer->updateTime, pNewConsumer->updateTime);
-  atomic_exchange_32(&pOldConsumer->version, pNewConsumer->version);
-
-  taosWLockLatch(&pOldConsumer->lock);
+static int32_t mndConsumerActionUpdate(SSdb *pSdb, SMqConsumerObj *pOldConsumer, SMqConsumerObj *pNewConsumer) {
+  mTrace("consumer:%ld, perform update action", pOldConsumer->consumerId);
 
   // TODO handle update
+  /*taosWLockLatch(&pOldConsumer->lock);*/
+  /*taosWUnLockLatch(&pOldConsumer->lock);*/
 
-  taosWUnLockLatch(&pOldConsumer->lock);
   return 0;
 }
 
-SConsumerObj *mndAcquireConsumer(SMnode *pMnode, int32_t consumerId) {
-  SSdb         *pSdb = pMnode->pSdb;
-  SConsumerObj *pConsumer = sdbAcquire(pSdb, SDB_CONSUMER, &consumerId);
+SMqConsumerObj *mndAcquireConsumer(SMnode *pMnode, int32_t consumerId) {
+  SSdb           *pSdb = pMnode->pSdb;
+  SMqConsumerObj *pConsumer = sdbAcquire(pSdb, SDB_CONSUMER, &consumerId);
   if (pConsumer == NULL) {
     /*terrno = TSDB_CODE_MND_CONSUMER_NOT_EXIST;*/
   }
   return pConsumer;
 }
 
-void mndReleaseConsumer(SMnode *pMnode, SConsumerObj *pConsumer) {
+void mndReleaseConsumer(SMnode *pMnode, SMqConsumerObj *pConsumer) {
   SSdb *pSdb = pMnode->pSdb;
   sdbRelease(pSdb, pConsumer);
 }
@@ -220,48 +188,185 @@ static int32_t mndProcessSubscribeReq(SMnodeMsg *pMsg) {
   char            *msgStr = pMsg->rpcMsg.pCont;
   SCMSubscribeReq *pSubscribe;
   tDeserializeSCMSubscribeReq(msgStr, pSubscribe);
-  int     topicNum = pSubscribe->topicNum;
   int64_t consumerId = pSubscribe->consumerId;
   char   *consumerGroup = pSubscribe->consumerGroup;
-  // get consumer group and add client into it
-  SCGroupObj *pCGroup = sdbAcquire(pMnode->pSdb, SDB_CGROUP, consumerGroup);
-  if (pCGroup != NULL) {
-    // iterate the list until finding the consumer
-    // add consumer to cgroup list if not found
-    // put new record
+
+  SArray *newSub = NULL;
+  int     newTopicNum = pSubscribe->topicNum;
+  if (newTopicNum) {
+    newSub = taosArrayInit(newTopicNum, sizeof(SMqConsumerTopic));
+  }
+  for (int i = 0; i < newTopicNum; i++) {
+    char             *topic = pSubscribe->topicName[i];
+    SMqConsumerTopic *pConsumerTopic = malloc(sizeof(SMqConsumerTopic));
+    if (pConsumerTopic == NULL) {
+      terrno = TSDB_CODE_OUT_OF_MEMORY;
+      // TODO: free
+      return -1;
+    }
+    pConsumerTopic->vgroups = tdListNew(sizeof(int64_t));
+    taosArrayPush(newSub, pConsumerTopic);
+    free(pConsumerTopic);
+  }
+  taosArraySortString(newSub, taosArrayCompareString);
+
+  SArray         *oldSub = NULL;
+  int             oldTopicNum = 0;
+  SMqConsumerObj *pConsumer = mndAcquireConsumer(pMnode, consumerId);
+  if (pConsumer == NULL) {
+    // create consumer
+    pConsumer = malloc(sizeof(SMqConsumerObj));
+    if (pConsumer == NULL) {
+      terrno = TSDB_CODE_OUT_OF_MEMORY;
+      return -1;
+    }
+    strcpy(pConsumer->cgroup, pSubscribe->consumerGroup);
+
+  } else {
+    oldSub = pConsumer->topics;
+    oldTopicNum = taosArrayGetSize(oldSub);
+  }
+  STrans *pTrans = mndTransCreate(pMnode, TRN_POLICY_RETRY, &pMsg->rpcMsg);
+  if (pTrans == NULL) {
+    return -1;
   }
 
-  SConsumerObj *pConsumer = mndAcquireConsumer(pMnode, consumerId);
-  if (pConsumer != NULL) {
-    //reset topic list
-  }
-
-  for (int i = 0; i < topicNum; i++) {
-    char *topicName = pSubscribe->topicName[i];
-    STopicObj *pTopic = mndAcquireTopic(pMnode, topicName);
-    //get 
-    // consumer id
-    SList *list = pTopic->consumerIds;
-    // add the consumer if not in the list
-    //
-    SList* topicList = pConsumer->topics;
-    //add to topic
+  int i = 0, j = 0;
+  while (i < newTopicNum || j < oldTopicNum) {
+    SMqConsumerTopic *pOldTopic = NULL;
+    SMqConsumerTopic *pNewTopic = NULL;
+    if (i >= newTopicNum) {
+      // encode unset topic msg to all vnodes related to that topic
+      pOldTopic = taosArrayGet(oldSub, j);
+      j++;
+    } else if (j >= oldTopicNum) {
+      pNewTopic = taosArrayGet(newSub, i);
+    } else {
+      pNewTopic = taosArrayGet(newSub, i);
+      pOldTopic = taosArrayGet(oldSub, j);
+
+      char *newName = pNewTopic->name;
+      char *oldName = pOldTopic->name;
+      int   comp = compareLenPrefixedStr(newName, oldName);
+      if (comp == 0) {
+        // do nothing
+        pOldTopic = pNewTopic = NULL;
+        i++;
+        j++;
+        continue;
+      } else if (comp < 0) {
+        pOldTopic = NULL;
+        i++;
+      } else {
+        pNewTopic = NULL;
+        j++;
+      }
+    }
+
+    if (pOldTopic != NULL) {
+      ASSERT(pNewTopic == NULL);
+      char     *oldTopicName = pOldTopic->name;
+      SList    *vgroups = pOldTopic->vgroups;
+      SListIter iter;
+      tdListInitIter(vgroups, &iter, TD_LIST_FORWARD);
+      SListNode *pn;
+
+      SMqTopicObj *pTopic = mndAcquireTopic(pMnode, oldTopicName);
+      ASSERT(pTopic != NULL);
+      SMqCGroup *pGroup = taosHashGet(pTopic->cgroups, pSubscribe->consumerGroup, strlen(pSubscribe->consumerGroup));
+      while ((pn = tdListNext(&iter)) != NULL) {
+        int32_t vgId = *(int64_t *)pn->data;
+        SVgObj *pVgObj = mndAcquireVgroup(pMnode, vgId);
+        // TODO release
+        if (pVgObj == NULL) {
+          // TODO handle error
+          continue;
+        }
+        // acquire and get epset
+        void *pMqVgSetReq =
+            mndBuildMqVGroupSetReq(pMnode, oldTopicName, vgId, pSubscribe->consumerId, pSubscribe->consumerGroup);
+        // TODO:serialize
+        if (pMsg == NULL) {
+          terrno = TSDB_CODE_OUT_OF_MEMORY;
+          return -1;
+        }
+        STransAction action = {0};
+        action.epSet = mndGetVgroupEpset(pMnode, pVgObj);
+        action.pCont = pMqVgSetReq;
+        action.contLen = 0;  // TODO
+        action.msgType = TDMT_VND_MQ_SET_CONN;
+        if (mndTransAppendRedoAction(pTrans, &action) != 0) {
+          free(pMqVgSetReq);
+          mndTransDrop(pTrans);
+          // TODO free
+          return -1;
+        }
+      }
+      taosHashRemove(pTopic->cgroups, pSubscribe->consumerGroup, strlen(pSubscribe->consumerGroup));
+
+    } else if (pNewTopic != NULL) {
+      ASSERT(pOldTopic == NULL);
+
+      char        *newTopicName = pNewTopic->name;
+      SMqTopicObj *pTopic = mndAcquireTopic(pMnode, newTopicName);
+      ASSERT(pTopic != NULL);
+
+      SMqCGroup *pGroup = taosHashGet(pTopic->cgroups, pSubscribe->consumerGroup, strlen(pSubscribe->consumerGroup));
+      if (pGroup == NULL) {
+        // add new group
+        pGroup = malloc(sizeof(SMqCGroup));
+        if (pGroup == NULL) {
+          terrno = TSDB_CODE_OUT_OF_MEMORY;
+          return -1;
+        }
+        pGroup->consumerIds = tdListNew(sizeof(int64_t));
+        if (pGroup->consumerIds == NULL) {
+          free(pGroup);
+          terrno = TSDB_CODE_OUT_OF_MEMORY;
+          return -1;
+        }
+        pGroup->status = 0;
+        // add into cgroups
+        taosHashPut(pTopic->cgroups, pSubscribe->consumerGroup, strlen(pSubscribe->consumerGroup), pGroup,
+                    sizeof(SMqCGroup));
+      }
+
+      // put the consumer into list
+      // rebalance will be triggered by timer
+      tdListAppend(pGroup->consumerIds, &pSubscribe->consumerId);
+
+      SSdbRaw *pTopicRaw = mndTopicActionEncode(pTopic);
+      sdbSetRawStatus(pTopicRaw, SDB_STATUS_READY);
+      // TODO: error handling
+      mndTransAppendRedolog(pTrans, pTopicRaw);
+    } else {
+      ASSERT(0);
+    }
+  }
+  // destroy old sub
+  taosArrayDestroy(oldSub);
+  // put new sub into consumerobj
+  pConsumer->topics = newSub;
+
+  // persist consumerObj
+  SSdbRaw *pConsumerRaw = mndConsumerActionEncode(pConsumer);
+  sdbSetRawStatus(pConsumerRaw, SDB_STATUS_READY);
+  // TODO: error handling
+  mndTransAppendRedolog(pTrans, pConsumerRaw);
+
+  if (mndTransPrepare(pMnode, pTrans) != 0) {
+    mError("trans:%d, failed to prepare since %s", pTrans->id, terrstr());
+    mndTransDrop(pTrans);
+    return -1;
   }
 
+  // TODO: free memory
+  mndTransDrop(pTrans);
   return 0;
 }
 
-static int32_t mndProcessSubscribeRsp(SMnodeMsg *pMsg) { return 0; }
-
-static int32_t mndProcessSubscribeInternalReq(SMnodeMsg *pMsg) { return 0; }
-
 static int32_t mndProcessSubscribeInternalRsp(SMnodeMsg *pMsg) { return 0; }
 
-static int32_t mndProcessDropConsumerInRsp(SMnodeMsg *pMsg) {
-  mndTransProcessRsp(pMsg);
-  return 0;
-}
-
 static int32_t mndProcessConsumerMetaMsg(SMnodeMsg *pMsg) {
   SMnode        *pMnode = pMsg->pMnode;
   STableInfoMsg *pInfo = pMsg->rpcMsg.pCont;
@@ -339,7 +444,7 @@ static int32_t mndGetNumOfConsumers(SMnode *pMnode, char *dbName, int32_t *pNumO
   int32_t numOfConsumers = 0;
   void   *pIter = NULL;
   while (1) {
-    SConsumerObj *pConsumer = NULL;
+    SMqConsumerObj *pConsumer = NULL;
     pIter = sdbFetch(pSdb, SDB_CONSUMER, pIter, (void **)&pConsumer);
     if (pIter == NULL) break;
 
@@ -402,49 +507,6 @@ static int32_t mndGetConsumerMeta(SMnodeMsg *pMsg, SShowObj *pShow, STableMetaMs
   return 0;
 }
 
-static int32_t mndRetrieveCGroup(SMnodeMsg *pMsg, SShowObj *pShow, char *data, int32_t rows) {
-  SMnode       *pMnode = pMsg->pMnode;
-  SSdb         *pSdb = pMnode->pSdb;
-  int32_t       numOfRows = 0;
-  SCGroupObj   *pCGroup = NULL;
-  int32_t       cols = 0;
-  char         *pWrite;
-  char          prefix[64] = {0};
-
-  tstrncpy(prefix, pShow->db, 64);
-  strcat(prefix, TS_PATH_DELIMITER);
-  int32_t prefixLen = (int32_t)strlen(prefix);
-
-  while (numOfRows < rows) {
-    pShow->pIter = sdbFetch(pSdb, SDB_CONSUMER, pShow->pIter, (void **)&pCGroup);
-    if (pShow->pIter == NULL) break;
-
-    if (strncmp(pCGroup->name, prefix, prefixLen) != 0) {
-      sdbRelease(pSdb, pCGroup);
-      continue;
-    }
-
-    cols = 0;
-
-    char consumerName[TSDB_TABLE_NAME_LEN] = {0};
-    tstrncpy(consumerName, pCGroup->name + prefixLen, TSDB_TABLE_NAME_LEN);
-    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    STR_TO_VARSTR(pWrite, consumerName);
-    cols++;
-
-    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    *(int64_t *)pWrite = pCGroup->createTime;
-    cols++;
-
-    numOfRows++;
-    sdbRelease(pSdb, pCGroup);
-  }
-
-  pShow->numOfReads += numOfRows;
-  mndVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
-  return numOfRows;
-}
-
 static void mndCancelGetNextConsumer(SMnode *pMnode, void *pIter) {
   SSdb *pSdb = pMnode->pSdb;
   sdbCancelFetch(pSdb, pIter);
diff --git a/source/dnode/mnode/impl/src/mndTopic.c b/source/dnode/mnode/impl/src/mndTopic.c
index 24e32e07b4..4f6567a50a 100644
--- a/source/dnode/mnode/impl/src/mndTopic.c
+++ b/source/dnode/mnode/impl/src/mndTopic.c
@@ -14,6 +14,7 @@
  */
 
 #define _DEFAULT_SOURCE
+#include "mndTopic.h"
 #include "mndDb.h"
 #include "mndDnode.h"
 #include "mndMnode.h"
@@ -27,18 +28,16 @@
 #define MND_TOPIC_VER_NUMBER 1
 #define MND_TOPIC_RESERVE_SIZE 64
 
-static SSdbRaw *mndTopicActionEncode(STopicObj *pTopic);
-static SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw);
-static int32_t  mndTopicActionInsert(SSdb *pSdb, STopicObj *pTopic);
-static int32_t  mndTopicActionDelete(SSdb *pSdb, STopicObj *pTopic);
-static int32_t  mndTopicActionUpdate(SSdb *pSdb, STopicObj *pTopic, STopicObj *pNewTopic);
-static int32_t  mndProcessCreateTopicMsg(SMnodeMsg *pMsg);
-static int32_t  mndProcessDropTopicMsg(SMnodeMsg *pMsg);
-static int32_t  mndProcessDropTopicInRsp(SMnodeMsg *pMsg);
-static int32_t  mndProcessTopicMetaMsg(SMnodeMsg *pMsg);
-static int32_t  mndGetTopicMeta(SMnodeMsg *pMsg, SShowObj *pShow, STableMetaMsg *pMeta);
-static int32_t  mndRetrieveTopic(SMnodeMsg *pMsg, SShowObj *pShow, char *data, int32_t rows);
-static void     mndCancelGetNextTopic(SMnode *pMnode, void *pIter);
+static int32_t mndTopicActionInsert(SSdb *pSdb, SMqTopicObj *pTopic);
+static int32_t mndTopicActionDelete(SSdb *pSdb, SMqTopicObj *pTopic);
+static int32_t mndTopicActionUpdate(SSdb *pSdb, SMqTopicObj *pTopic, SMqTopicObj *pNewTopic);
+static int32_t mndProcessCreateTopicMsg(SMnodeMsg *pMsg);
+static int32_t mndProcessDropTopicMsg(SMnodeMsg *pMsg);
+static int32_t mndProcessDropTopicInRsp(SMnodeMsg *pMsg);
+static int32_t mndProcessTopicMetaMsg(SMnodeMsg *pMsg);
+static int32_t mndGetTopicMeta(SMnodeMsg *pMsg, SShowObj *pShow, STableMetaMsg *pMeta);
+static int32_t mndRetrieveTopic(SMnodeMsg *pMsg, SShowObj *pShow, char *data, int32_t rows);
+static void    mndCancelGetNextTopic(SMnode *pMnode, void *pIter);
 
 int32_t mndInitTopic(SMnode *pMnode) {
   SSdbTable table = {.sdbType = SDB_TOPIC,
@@ -58,8 +57,9 @@ int32_t mndInitTopic(SMnode *pMnode) {
 
 void mndCleanupTopic(SMnode *pMnode) {}
 
-static SSdbRaw *mndTopicActionEncode(STopicObj *pTopic) {
-  int32_t  size = sizeof(STopicObj) + MND_TOPIC_RESERVE_SIZE;
+SSdbRaw *mndTopicActionEncode(SMqTopicObj *pTopic) {
+  int32_t  len;
+  int32_t  size = sizeof(SMqTopicObj) + MND_TOPIC_RESERVE_SIZE;
   SSdbRaw *pRaw = sdbAllocRaw(SDB_TOPIC, MND_TOPIC_VER_NUMBER, size);
   if (pRaw == NULL) return NULL;
 
@@ -71,10 +71,15 @@ static SSdbRaw *mndTopicActionEncode(STopicObj *pTopic) {
   SDB_SET_INT64(pRaw, dataPos, pTopic->uid);
   SDB_SET_INT64(pRaw, dataPos, pTopic->dbUid);
   SDB_SET_INT32(pRaw, dataPos, pTopic->version);
-  SDB_SET_INT32(pRaw, dataPos, pTopic->execLen);
-  SDB_SET_BINARY(pRaw, dataPos, pTopic->executor, pTopic->execLen);
   SDB_SET_INT32(pRaw, dataPos, pTopic->sqlLen);
   SDB_SET_BINARY(pRaw, dataPos, pTopic->sql, pTopic->sqlLen);
+  SDB_SET_INT32(pRaw, dataPos, pTopic->sqlLen);
+  len = strlen(pTopic->logicalPlan);
+  SDB_SET_INT32(pRaw, dataPos, len);
+  SDB_SET_BINARY(pRaw, dataPos, pTopic->logicalPlan, len);
+  len = strlen(pTopic->physicalPlan);
+  SDB_SET_INT32(pRaw, dataPos, len);
+  SDB_SET_BINARY(pRaw, dataPos, pTopic->physicalPlan, len);
 
   SDB_SET_RESERVE(pRaw, dataPos, MND_TOPIC_RESERVE_SIZE);
   SDB_SET_DATALEN(pRaw, dataPos);
@@ -82,7 +87,7 @@ static SSdbRaw *mndTopicActionEncode(STopicObj *pTopic) {
   return pRaw;
 }
 
-static SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw) {
+SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw) {
   int8_t sver = 0;
   if (sdbGetRawSoftVer(pRaw, &sver) != 0) return NULL;
 
@@ -92,11 +97,12 @@ static SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw) {
     return NULL;
   }
 
-  int32_t    size = sizeof(STopicObj) + TSDB_MAX_COLUMNS * sizeof(SSchema);
-  SSdbRow   *pRow = sdbAllocRow(size);
-  STopicObj *pTopic = sdbGetRowObj(pRow);
+  int32_t      size = sizeof(SMqTopicObj) + TSDB_MAX_COLUMNS * sizeof(SSchema);
+  SSdbRow     *pRow = sdbAllocRow(size);
+  SMqTopicObj *pTopic = sdbGetRowObj(pRow);
   if (pTopic == NULL) return NULL;
 
+  int32_t len;
   int32_t dataPos = 0;
   SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->name, TSDB_TABLE_FNAME_LEN);
   SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->db, TSDB_DB_FNAME_LEN);
@@ -105,49 +111,51 @@ static SSdbRow *mndTopicActionDecode(SSdbRaw *pRaw) {
   SDB_GET_INT64(pRaw, pRow, dataPos, &pTopic->uid);
   SDB_GET_INT64(pRaw, pRow, dataPos, &pTopic->dbUid);
   SDB_GET_INT32(pRaw, pRow, dataPos, &pTopic->version);
-  SDB_GET_INT32(pRaw, pRow, dataPos, &pTopic->execLen);
-  SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->executor, pTopic->execLen);
   SDB_GET_INT32(pRaw, pRow, dataPos, &pTopic->sqlLen);
   SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->sql, pTopic->sqlLen);
+  SDB_GET_INT32(pRaw, pRow, dataPos, &len);
+  SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->logicalPlan, len);
+  SDB_GET_INT32(pRaw, pRow, dataPos, &len);
+  SDB_GET_BINARY(pRaw, pRow, dataPos, pTopic->physicalPlan, len);
 
   SDB_GET_RESERVE(pRaw, pRow, dataPos, MND_TOPIC_RESERVE_SIZE);
 
   return pRow;
 }
 
-static int32_t mndTopicActionInsert(SSdb *pSdb, STopicObj *pTopic) {
+static int32_t mndTopicActionInsert(SSdb *pSdb, SMqTopicObj *pTopic) {
   mTrace("topic:%s, perform insert action", pTopic->name);
   return 0;
 }
 
-static int32_t mndTopicActionDelete(SSdb *pSdb, STopicObj *pTopic) {
+static int32_t mndTopicActionDelete(SSdb *pSdb, SMqTopicObj *pTopic) {
   mTrace("topic:%s, perform delete action", pTopic->name);
   return 0;
 }
 
-static int32_t mndTopicActionUpdate(SSdb *pSdb, STopicObj *pOldTopic, STopicObj *pNewTopic) {
+static int32_t mndTopicActionUpdate(SSdb *pSdb, SMqTopicObj *pOldTopic, SMqTopicObj *pNewTopic) {
   mTrace("topic:%s, perform update action", pOldTopic->name);
   atomic_exchange_32(&pOldTopic->updateTime, pNewTopic->updateTime);
   atomic_exchange_32(&pOldTopic->version, pNewTopic->version);
 
   taosWLockLatch(&pOldTopic->lock);
-  
-  //TODO handle update
+
+  // TODO handle update
 
   taosWUnLockLatch(&pOldTopic->lock);
   return 0;
 }
 
-STopicObj *mndAcquireTopic(SMnode *pMnode, char *topicName) {
-  SSdb      *pSdb = pMnode->pSdb;
-  STopicObj *pTopic = sdbAcquire(pSdb, SDB_TOPIC, topicName);
+SMqTopicObj *mndAcquireTopic(SMnode *pMnode, char *topicName) {
+  SSdb        *pSdb = pMnode->pSdb;
+  SMqTopicObj *pTopic = sdbAcquire(pSdb, SDB_TOPIC, topicName);
   if (pTopic == NULL) {
     terrno = TSDB_CODE_MND_TOPIC_NOT_EXIST;
   }
   return pTopic;
 }
 
-void mndReleaseTopic(SMnode *pMnode, STopicObj *pTopic) {
+void mndReleaseTopic(SMnode *pMnode, SMqTopicObj *pTopic) {
   SSdb *pSdb = pMnode->pSdb;
   sdbRelease(pSdb, pTopic);
 }
@@ -162,7 +170,7 @@ static SDbObj *mndAcquireDbByTopic(SMnode *pMnode, char *topicName) {
   return mndAcquireDb(pMnode, db);
 }
 
-static SDDropTopicMsg *mndBuildDropTopicMsg(SMnode *pMnode, SVgObj *pVgroup, STopicObj *pTopic) {
+static SDDropTopicMsg *mndBuildDropTopicMsg(SMnode *pMnode, SVgObj *pVgroup, SMqTopicObj *pTopic) {
   int32_t contLen = sizeof(SDDropTopicMsg);
 
   SDDropTopicMsg *pDrop = calloc(1, contLen);
@@ -185,7 +193,7 @@ static int32_t mndCheckCreateTopicMsg(SCMCreateTopicReq *pCreate) {
 }
 
 static int32_t mndCreateTopic(SMnode *pMnode, SMnodeMsg *pMsg, SCMCreateTopicReq *pCreate, SDbObj *pDb) {
-  STopicObj topicObj = {0};
+  SMqTopicObj topicObj = {0};
   tstrncpy(topicObj.name, pCreate->name, TSDB_TABLE_FNAME_LEN);
   tstrncpy(topicObj.db, pDb->name, TSDB_DB_FNAME_LEN);
   topicObj.createTime = taosGetTimestampMs();
@@ -197,13 +205,14 @@ static int32_t mndCreateTopic(SMnode *pMnode, SMnodeMsg *pMsg, SCMCreateTopicReq
   SSdbRaw *pTopicRaw = mndTopicActionEncode(&topicObj);
   if (pTopicRaw == NULL) return -1;
   if (sdbSetRawStatus(pTopicRaw, SDB_STATUS_READY) != 0) return -1;
+  // TODO: replace with trans to support recovery
   return sdbWrite(pMnode->pSdb, pTopicRaw);
 }
 
 static int32_t mndProcessCreateTopicMsg(SMnodeMsg *pMsg) {
-  SMnode        *pMnode = pMsg->pMnode;
-  char *msgStr = pMsg->rpcMsg.pCont;
-  SCMCreateTopicReq* pCreate;
+  SMnode            *pMnode = pMsg->pMnode;
+  char              *msgStr = pMsg->rpcMsg.pCont;
+  SCMCreateTopicReq *pCreate;
   tDeserializeSCMCreateTopicReq(msgStr, pCreate);
 
   mDebug("topic:%s, start to create", pCreate->name);
@@ -213,7 +222,7 @@ static int32_t mndProcessCreateTopicMsg(SMnodeMsg *pMsg) {
     return -1;
   }
 
-  STopicObj *pTopic = mndAcquireTopic(pMnode, pCreate->name);
+  SMqTopicObj *pTopic = mndAcquireTopic(pMnode, pCreate->name);
   if (pTopic != NULL) {
     sdbRelease(pMnode->pSdb, pTopic);
     if (pCreate->igExists) {
@@ -245,9 +254,7 @@ static int32_t mndProcessCreateTopicMsg(SMnodeMsg *pMsg) {
   return TSDB_CODE_MND_ACTION_IN_PROGRESS;
 }
 
-static int32_t mndDropTopic(SMnode *pMnode, SMnodeMsg *pMsg, STopicObj *pTopic) {
-  return 0;
-}
+static int32_t mndDropTopic(SMnode *pMnode, SMnodeMsg *pMsg, SMqTopicObj *pTopic) { return 0; }
 
 static int32_t mndProcessDropTopicMsg(SMnodeMsg *pMsg) {
   SMnode        *pMnode = pMsg->pMnode;
@@ -255,7 +262,7 @@ static int32_t mndProcessDropTopicMsg(SMnodeMsg *pMsg) {
 
   mDebug("topic:%s, start to drop", pDrop->name);
 
-  STopicObj *pTopic = mndAcquireTopic(pMnode, pDrop->name);
+  SMqTopicObj *pTopic = mndAcquireTopic(pMnode, pDrop->name);
   if (pTopic == NULL) {
     if (pDrop->igNotExists) {
       mDebug("topic:%s, not exist, ignore not exist is set", pDrop->name);
@@ -361,7 +368,7 @@ static int32_t mndGetNumOfTopics(SMnode *pMnode, char *dbName, int32_t *pNumOfTo
   int32_t numOfTopics = 0;
   void   *pIter = NULL;
   while (1) {
-    STopicObj *pTopic = NULL;
+    SMqTopicObj *pTopic = NULL;
     pIter = sdbFetch(pSdb, SDB_TOPIC, pIter, (void **)&pTopic);
     if (pIter == NULL) break;
 
@@ -440,13 +447,13 @@ static void mndExtractTableName(char *tableId, char *name) {
 }
 
 static int32_t mndRetrieveTopic(SMnodeMsg *pMsg, SShowObj *pShow, char *data, int32_t rows) {
-  SMnode    *pMnode = pMsg->pMnode;
-  SSdb      *pSdb = pMnode->pSdb;
-  int32_t    numOfRows = 0;
-  STopicObj *pTopic = NULL;
-  int32_t    cols = 0;
-  char      *pWrite;
-  char       prefix[64] = {0};
+  SMnode      *pMnode = pMsg->pMnode;
+  SSdb        *pSdb = pMnode->pSdb;
+  int32_t      numOfRows = 0;
+  SMqTopicObj *pTopic = NULL;
+  int32_t      cols = 0;
+  char        *pWrite;
+  char         prefix[64] = {0};
 
   tstrncpy(prefix, pShow->db, 64);
   strcat(prefix, TS_PATH_DELIMITER);
diff --git a/source/libs/wal/src/walMeta.c b/source/libs/wal/src/walMeta.c
index 0f155f9553..6164ec2baf 100644
--- a/source/libs/wal/src/walMeta.c
+++ b/source/libs/wal/src/walMeta.c
@@ -261,15 +261,18 @@ int walLoadMeta(SWal* pWal) {
   memset(buf, 0, size + 5);
   int tfd = tfOpenRead(fnameStr);
   if (tfRead(tfd, buf, size) != size) {
+    tfClose(tfd);
     free(buf);
     return -1;
   }
   // load into fileInfoSet
   int code = walMetaDeserialize(pWal, buf);
   if (code != 0) {
+    tfClose(tfd);
     free(buf);
     return -1;
   }
+  tfClose(tfd);
   free(buf);
   return 0;
 }
diff --git a/source/libs/wal/src/walRead.c b/source/libs/wal/src/walRead.c
index c80fb4eed8..67c8694fd6 100644
--- a/source/libs/wal/src/walRead.c
+++ b/source/libs/wal/src/walRead.c
@@ -15,6 +15,7 @@
 
 #include "tfile.h"
 #include "walInt.h"
+#include "taoserror.h"
 
 SWalReadHandle *walOpenReadHandle(SWal *pWal) {
   SWalReadHandle *pRead = malloc(sizeof(SWalReadHandle));
@@ -30,6 +31,7 @@ SWalReadHandle *walOpenReadHandle(SWal *pWal) {
   pRead->status = 0;
   pRead->pHead = malloc(sizeof(SWalHead));
   if (pRead->pHead == NULL) {
+    terrno = TSDB_CODE_WAL_OUT_OF_MEMORY;
     free(pRead);
     return NULL;
   }
@@ -55,16 +57,19 @@ static int32_t walReadSeekFilePos(SWalReadHandle *pRead, int64_t fileFirstVer, i
   int64_t offset = (ver - fileFirstVer) * sizeof(SWalIdxEntry);
   code = tfLseek(idxTfd, offset, SEEK_SET);
   if (code < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   SWalIdxEntry entry;
   if (tfRead(idxTfd, &entry, sizeof(SWalIdxEntry)) != sizeof(SWalIdxEntry)) {
+    terrno = TSDB_CODE_WAL_FILE_CORRUPTED;
     return -1;
   }
   // TODO:deserialize
   ASSERT(entry.ver == ver);
   code = tfLseek(logTfd, entry.offset, SEEK_SET);
   if (code < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   return code;
@@ -79,6 +84,7 @@ static int32_t walReadChangeFile(SWalReadHandle *pRead, int64_t fileFirstVer) {
   walBuildLogName(pRead->pWal, fileFirstVer, fnameStr);
   int64_t logTfd = tfOpenRead(fnameStr);
   if (logTfd < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
 
@@ -100,6 +106,7 @@ static int32_t walReadSeekVer(SWalReadHandle *pRead, int64_t ver) {
     return 0;
   }
   if (ver > pWal->vers.lastVer || ver < pWal->vers.firstVer) {
+    terrno = TSDB_CODE_WAL_INVALID_VER;
     return -1;
   }
   if (ver < pWal->vers.snapshotVer) {
@@ -113,7 +120,6 @@ static int32_t walReadSeekVer(SWalReadHandle *pRead, int64_t ver) {
   if (pRead->curFileFirstVer != pRet->firstVer) {
     code = walReadChangeFile(pRead, pRet->firstVer);
     if (code < 0) {
-      // TODO: set error flag
       return -1;
     }
   }
@@ -132,7 +138,7 @@ int32_t walReadWithHandle(SWalReadHandle *pRead, int64_t ver) {
   // TODO: check wal life
   if (pRead->curVersion != ver) {
     code = walReadSeekVer(pRead, ver);
-    if (code != 0) {
+    if (code < 0) {
       return -1;
     }
   }
@@ -145,11 +151,13 @@ int32_t walReadWithHandle(SWalReadHandle *pRead, int64_t ver) {
   }
   code = walValidHeadCksum(pRead->pHead);
   if (code != 0) {
+    terrno = TSDB_CODE_WAL_FILE_CORRUPTED;
     return -1;
   }
   if (pRead->capacity < pRead->pHead->head.len) {
     void *ptr = realloc(pRead->pHead, sizeof(SWalHead) + pRead->pHead->head.len);
     if (ptr == NULL) {
+      terrno = TSDB_CODE_WAL_OUT_OF_MEMORY;
       return -1;
     }
     pRead->pHead = ptr;
@@ -163,6 +171,7 @@ int32_t walReadWithHandle(SWalReadHandle *pRead, int64_t ver) {
 
   code = walValidBodyCksum(pRead->pHead);
   if (code != 0) {
+    terrno = TSDB_CODE_WAL_FILE_CORRUPTED;
     return -1;
   }
   pRead->curVersion++;
diff --git a/source/libs/wal/src/walSeek.c b/source/libs/wal/src/walSeek.c
index 1f9b7b6e58..1d9f7bdf4d 100644
--- a/source/libs/wal/src/walSeek.c
+++ b/source/libs/wal/src/walSeek.c
@@ -30,17 +30,20 @@ static int walSeekFilePos(SWal* pWal, int64_t ver) {
   int64_t idxOff = walGetVerIdxOffset(pWal, ver);
   code = tfLseek(idxTfd, idxOff, SEEK_SET);
   if (code != 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   SWalIdxEntry entry;
   // TODO:deserialize
   code = tfRead(idxTfd, &entry, sizeof(SWalIdxEntry));
   if (code != 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   ASSERT(entry.ver == ver);
   code = tfLseek(logTfd, entry.offset, SEEK_CUR);
   if (code < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   return code;
@@ -56,11 +59,13 @@ int walChangeFileToLast(SWal* pWal) {
   walBuildIdxName(pWal, fileFirstVer, fnameStr);
   idxTfd = tfOpenReadWrite(fnameStr);
   if (idxTfd < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   walBuildLogName(pWal, fileFirstVer, fnameStr);
   logTfd = tfOpenReadWrite(fnameStr);
   if (logTfd < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   // switch file
@@ -76,11 +81,12 @@ int walChangeFile(SWal* pWal, int64_t ver) {
   code = tfClose(pWal->writeLogTfd);
   if (code != 0) {
     // TODO
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   code = tfClose(pWal->writeIdxTfd);
   if (code != 0) {
-    // TODO
+    terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
   SWalFileInfo tmpInfo;
@@ -113,6 +119,7 @@ int walSeekVer(SWal* pWal, int64_t ver) {
     return 0;
   }
   if (ver > pWal->vers.lastVer || ver < pWal->vers.firstVer) {
+    terrno = TSDB_CODE_WAL_INVALID_VER;
     return -1;
   }
   if (ver < pWal->vers.snapshotVer) {
diff --git a/source/libs/wal/src/walWrite.c b/source/libs/wal/src/walWrite.c
index c8ffd9d07d..5e26dd8278 100644
--- a/source/libs/wal/src/walWrite.c
+++ b/source/libs/wal/src/walWrite.c
@@ -25,6 +25,7 @@ int32_t walCommit(SWal *pWal, int64_t ver) {
   ASSERT(pWal->vers.commitVer >= pWal->vers.snapshotVer);
   ASSERT(pWal->vers.commitVer <= pWal->vers.lastVer);
   if (ver < pWal->vers.commitVer || ver > pWal->vers.lastVer) {
+    terrno = TSDB_CODE_WAL_INVALID_VER;
     return -1;
   }
   pWal->vers.commitVer = ver;
@@ -38,6 +39,7 @@ int32_t walRollback(SWal *pWal, int64_t ver) {
     return 0;
   }
   if (ver > pWal->vers.lastVer || ver < pWal->vers.commitVer) {
+    terrno = TSDB_CODE_WAL_INVALID_VER;
     return -1;
   }
   pthread_mutex_lock(&pWal->mutex);