diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 9f58fe13906873af73c244c210c0a03ebaa33705..df176314e5cb1371dd5465c8a24ae4e7b77e74ab 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -40,7 +40,7 @@ uint32_t tsServerIp;
 
 int (*tscBuildMsg[TSDB_SQL_MAX])(SSqlObj *pSql);
 int (*tscProcessMsgRsp[TSDB_SQL_MAX])(SSqlObj *pSql);
-void (*tscUpdateVnodeMsg[TSDB_SQL_MAX])(SSqlObj *pSql);
+void (*tscUpdateVnodeMsg[TSDB_SQL_MAX])(SSqlObj *pSql, char* buf);
 void tscProcessActivityTimer(void *handle, void *tmrId);
 int tscKeepConn[TSDB_SQL_MAX] = {0};
 
@@ -206,10 +206,24 @@ int tscSendMsgToServer(SSqlObj *pSql) {
   }
 
   if (pSql->thandle) {
+    /*
+     * the total length of message
+     * rpc header + actual message body + digest
+     *
+     * the pSql object may be released automatically during insert procedure, in which the access of
+     * message body by using "if (pHeader->msgType & 1)" may cause the segment fault.
+     *
+     */
+    int32_t totalMsgLen = pSql->cmd.payloadLen + tsRpcHeadSize + sizeof(STaosDigest);
+
+    // the memory will be released by taosProcessResponse, so no memory leak here
+    char* buf = malloc(totalMsgLen);
+    memcpy(buf, pSql->cmd.payload, totalMsgLen);
+
     tscTrace("%p msg:%s is sent to server", pSql, taosMsg[pSql->cmd.msgType]);
-    char *pStart = taosBuildReqHeader(pSql->thandle, pSql->cmd.msgType, pSql->cmd.payload);
+    char *pStart = taosBuildReqHeader(pSql->thandle, pSql->cmd.msgType, buf);
     if (pStart) {
-      if (tscUpdateVnodeMsg[pSql->cmd.command]) (*tscUpdateVnodeMsg[pSql->cmd.command])(pSql);
+      if (tscUpdateVnodeMsg[pSql->cmd.command]) (*tscUpdateVnodeMsg[pSql->cmd.command])(pSql, buf);
       int ret = taosSendMsgToPeerH(pSql->thandle, pStart, pSql->cmd.payloadLen, pSql);
       if (ret >= 0) code = 0;
       tscTrace("%p send msg ret:%d code:%d sig:%p", pSql, ret, code, pSql->signature);
@@ -1007,12 +1021,12 @@ int tscBuildRetrieveMsg(SSqlObj *pSql) {
   return msgLen;
 }
 
-void tscUpdateVnodeInSubmitMsg(SSqlObj *pSql) {
+void tscUpdateVnodeInSubmitMsg(SSqlObj *pSql, char* buf) {
   SShellSubmitMsg *pShellMsg;
   char *           pMsg;
   SMeterMeta *     pMeterMeta = pSql->cmd.pMeterMeta;
 
-  pMsg = pSql->cmd.payload + tsRpcHeadSize;
+  pMsg = buf + tsRpcHeadSize;
 
   pShellMsg = (SShellSubmitMsg *)pMsg;
   pShellMsg->vnode = htons(pMeterMeta->vpeerDesc[pSql->index].vnode);
@@ -1042,9 +1056,9 @@ int tscBuildSubmitMsg(SSqlObj *pSql) {
   return msgLen;
 }
 
-void tscUpdateVnodeInQueryMsg(SSqlObj *pSql) {
+void tscUpdateVnodeInQueryMsg(SSqlObj *pSql, char* buf) {
   SSqlCmd *pCmd = &pSql->cmd;
-  char *   pStart = pCmd->payload + tsRpcHeadSize;
+  char *   pStart = buf + tsRpcHeadSize;
 
   SQueryMeterMsg *pQueryMsg = (SQueryMeterMsg *)pStart;
 
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 34dea0be9e835ae7225d8fe0f886b78a2a827413..381bd79bf81afd19c4c5e545d8b75173f898a6cd 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -110,7 +110,7 @@ void taos_init_imp() {
   rpcInit.numOfChanns = tscNumOfThreads;
   rpcInit.sessionsPerChann = tsMaxVnodeConnections / tscNumOfThreads;
   rpcInit.idMgmt = TAOS_ID_FREE;
-  rpcInit.noFree = 1;
+  rpcInit.noFree = 0;
   rpcInit.connType = TAOS_CONN_UDP;
   rpcInit.qhandle = tscQhandle;
   pVnodeConn = taosOpenRpc(&rpcInit);
@@ -131,7 +131,7 @@ void taos_init_imp() {
   rpcInit.numOfChanns = 1;
   rpcInit.sessionsPerChann = tsMaxMgmtConnections;
   rpcInit.idMgmt = TAOS_ID_FREE;
-  rpcInit.noFree = 1;
+  rpcInit.noFree = 0;
   rpcInit.connType = TAOS_CONN_UDP;
   rpcInit.qhandle = tscQhandle;
   pTscMgmtConn = taosOpenRpc(&rpcInit);
diff --git a/src/system/inc/vnodeUtil.h b/src/system/inc/vnodeUtil.h
index 2f619c85aa83bffd6b30c4f2f0d6be4c4d3eda2f..b7efcfaa38870b4eaee009d6eccfd6cb75e7d307 100644
--- a/src/system/inc/vnodeUtil.h
+++ b/src/system/inc/vnodeUtil.h
@@ -75,7 +75,7 @@ int32_t vnodeIncQueryRefCount(SQueryMeterMsg *pQueryMsg, SMeterSidExtInfo **pSid
 
 void vnodeDecQueryRefCount(SQueryMeterMsg *pQueryMsg, SMeterObj **pMeterObjList, int32_t numOfInc);
 
-int32_t vnodeTransferMeterState(SMeterObj* pMeterObj, int32_t state);
+int32_t vnodeSetMeterState(SMeterObj* pMeterObj, int32_t state);
 void vnodeClearMeterState(SMeterObj* pMeterObj, int32_t state);
 bool vnodeIsMeterState(SMeterObj* pMeterObj, int32_t state);
 void vnodeSetMeterDeleting(SMeterObj* pMeterObj);
diff --git a/src/system/src/vnodeImport.c b/src/system/src/vnodeImport.c
index d2493a5830674c29a9d76916126663622a5e5543..92ecaa7e0120bb36b9b21f574af95cef4003987b 100644
--- a/src/system/src/vnodeImport.c
+++ b/src/system/src/vnodeImport.c
@@ -285,7 +285,7 @@ void vnodeProcessImportTimer(void *param, void *tmrId) {
   pImport->retry++;
 
   //slow query will block the import operation
-  int32_t state = vnodeTransferMeterState(pObj, TSDB_METER_STATE_IMPORTING);
+  int32_t state = vnodeSetMeterState(pObj, TSDB_METER_STATE_IMPORTING);
   if (state >= TSDB_METER_STATE_DELETING) {
     dError("vid:%d sid:%d id:%s, meter is deleted, failed to import, state:%d",
            pObj->vnode, pObj->sid, pObj->meterId, state);
@@ -887,7 +887,7 @@ int vnodeImportPoints(SMeterObj *pObj, char *cont, int contLen, char source, voi
 
   if (*((TSKEY *)(pSubmit->payLoad + (rows - 1) * pObj->bytesPerPoint)) > pObj->lastKey) {
     vnodeClearMeterState(pObj, TSDB_METER_STATE_IMPORTING);
-    vnodeTransferMeterState(pObj, TSDB_METER_STATE_INSERT);
+    vnodeSetMeterState(pObj, TSDB_METER_STATE_INSERT);
     code = vnodeInsertPoints(pObj, cont, contLen, TSDB_DATA_SOURCE_LOG, NULL, pObj->sversion, &pointsImported);
 
     if (pShell) {
diff --git a/src/system/src/vnodeMeter.c b/src/system/src/vnodeMeter.c
index b8961e98ec4d75b5aafcbbd96529784ed92ae98b..62b6b64e22407defa861e94a3bb25d87cfcca646 100644
--- a/src/system/src/vnodeMeter.c
+++ b/src/system/src/vnodeMeter.c
@@ -676,7 +676,7 @@ void vnodeUpdateMeter(void *param, void *tmrId) {
     return;
   }
 
-  int32_t state = vnodeTransferMeterState(pObj, TSDB_METER_STATE_UPDATING);
+  int32_t state = vnodeSetMeterState(pObj, TSDB_METER_STATE_UPDATING);
   if (state >= TSDB_METER_STATE_DELETING) {
     dError("vid:%d sid:%d id:%s, meter is deleted, failed to update, state:%d",
            pObj->vnode, pObj->sid, pObj->meterId, state);
diff --git a/src/system/src/vnodeShell.c b/src/system/src/vnodeShell.c
index 03ddf522cea5eabf60151a6aefdec88fa02045d9..fda92d5d4c02dce2b066d79831eb573c3c7e72c2 100644
--- a/src/system/src/vnodeShell.c
+++ b/src/system/src/vnodeShell.c
@@ -183,8 +183,8 @@ void vnodeCloseShellVnode(int vnode) {
    * 1. The msg, as well as SRpcConn may be in the task queue, free it immediate will cause crash
    * 2. Free connection may cause *(SRpcConn*)pObj->thandle to be invalid to access.
    */
-  dTrace("vid:%d, delay 5sec to free resources", vnode);
-  taosTmrStart(vnodeDelayedFreeResource, 5000, v, vnodeTmrCtrl);
+  dTrace("vid:%d, delay 500ms to free resources", vnode);
+  taosTmrStart(vnodeDelayedFreeResource, 500, v, vnodeTmrCtrl);
 }
 
 void vnodeCleanUpShell() {
@@ -508,9 +508,9 @@ int vnodeProcessShellSubmitRequest(char *pMsg, int msgLen, SShellObj *pObj) {
 
     int32_t state = TSDB_METER_STATE_READY;
     if (pSubmit->import) {
-      state = vnodeTransferMeterState(pMeterObj, TSDB_METER_STATE_IMPORTING);
+      state = vnodeSetMeterState(pMeterObj, TSDB_METER_STATE_IMPORTING);
     } else {
-      state = vnodeTransferMeterState(pMeterObj, TSDB_METER_STATE_INSERT);
+      state = vnodeSetMeterState(pMeterObj, TSDB_METER_STATE_INSERT);
     }
 
     if (state == TSDB_METER_STATE_READY) {
diff --git a/src/system/src/vnodeStream.c b/src/system/src/vnodeStream.c
index d7b7f62baefcc2247a0c6007c2459266ea95ec8c..a8dcff231d6d12e8bceed83e37b0fd51592f67ca 100644
--- a/src/system/src/vnodeStream.c
+++ b/src/system/src/vnodeStream.c
@@ -55,7 +55,7 @@ void vnodeProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row) {
 
   int32_t numOfPoints = 0;
 
-  int32_t state = vnodeTransferMeterState(pObj, TSDB_METER_STATE_INSERT);
+  int32_t state = vnodeSetMeterState(pObj, TSDB_METER_STATE_INSERT);
   if (state == TSDB_METER_STATE_READY) {
     vnodeInsertPoints(pObj, (char *)pMsg, contLen, TSDB_DATA_SOURCE_SHELL, NULL, pObj->sversion, &numOfPoints);
     vnodeClearMeterState(pObj, TSDB_METER_STATE_INSERT);
diff --git a/src/system/src/vnodeUtil.c b/src/system/src/vnodeUtil.c
index f97b7cb00bc4809e73f02fcdeca7dec990f13607..f9d1966378df2934461329d515d9a6292258dbf2 100644
--- a/src/system/src/vnodeUtil.c
+++ b/src/system/src/vnodeUtil.c
@@ -586,7 +586,7 @@ void vnodeUpdateQueryColumnIndex(SQuery* pQuery, SMeterObj* pMeterObj) {
   }
 }
 
-int32_t vnodeTransferMeterState(SMeterObj* pMeterObj, int32_t state) {
+int32_t vnodeSetMeterState(SMeterObj* pMeterObj, int32_t state) {
   return __sync_val_compare_and_swap(&pMeterObj->state, TSDB_METER_STATE_READY, state);
 }
 
@@ -619,7 +619,7 @@ bool vnodeIsSafeToDeleteMeter(SVnodeObj* pVnode, int32_t sid) {
     return true;
   }
 
-  int32_t prev = vnodeTransferMeterState(pObj, TSDB_METER_STATE_DELETING);
+  int32_t prev = vnodeSetMeterState(pObj, TSDB_METER_STATE_DELETING);
 
   /*
    * if the meter is not in ready/deleting state, it must be in insert/import/update,