diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index eda6db8a2b5557bca3f567f53cde6e80b6e876af..26fe19d8be5d84b2b3430bc53bbc2cdcf50f7e32 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -248,6 +248,8 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
   SSqlRes *pRes = &pSql->res;
   SSqlCmd *pCmd = &pSql->cmd;
 
+  assert(*pSql->self == pSql);
+
   if (pObj->signature != pObj) {
     tscDebug("%p DB connection is closed, cmd:%d pObj:%p signature:%p", pSql, pCmd->command, pObj, pObj->signature);
 
@@ -263,6 +265,9 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     tscDebug("%p sqlObj needs to be released or DB connection is closed, cmd:%d type:%d, pObj:%p signature:%p",
         pSql, pCmd->command, pQueryInfo->type, pObj, pObj->signature);
 
+    void** p1 = p;
+    taosCacheRelease(tscObjCache, (void**) &p1, false);
+
     taosCacheRelease(tscObjCache, (void**) &p, true);
     rpcFreeCont(rpcMsg->pCont);
     return;
@@ -368,21 +373,20 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     rpcMsg->code = (*tscProcessMsgRsp[pCmd->command])(pSql);
   }
 
-  bool shouldFree = false;
+  bool shouldFree = tscShouldBeFreed(pSql);;
   if (rpcMsg->code != TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
     rpcMsg->code = (pRes->code == TSDB_CODE_SUCCESS) ? (int32_t)pRes->numOfRows : pRes->code;
-    
-    shouldFree = tscShouldBeFreed(pSql);
     (*pSql->fp)(pSql->param, pSql, rpcMsg->code);
-
-    if (shouldFree) {
-      void** p1 = p;
-      taosCacheRelease(tscObjCache, (void **)&p1, true);
-      tscDebug("%p sqlObj is automatically freed", pSql);
-    }
   }
 
+  void** p1 = p;
   taosCacheRelease(tscObjCache, (void**) &p, false);
+
+  if (shouldFree) {
+    taosCacheRelease(tscObjCache, (void **)&p1, true);
+    tscDebug("%p sqlObj is automatically freed", pSql);
+  }
+
   rpcFreeCont(rpcMsg->pCont);
 }
 
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index 33996307ad6ecb53f82c9aae4aaf8ae08b57a9e7..58859e944cc7e367da9ed924d8755d15b9a8c2bb 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -26,6 +26,7 @@
 #include "tsclient.h"
 #include "ttokendef.h"
 #include "tutil.h"
+#include "tscProfile.h"
 
 static bool validImpl(const char* str, size_t maxsize) {
   if (str == NULL) {
@@ -536,39 +537,53 @@ int taos_select_db(TAOS *taos, const char *db) {
 }
 
 // send free message to vnode to free qhandle and corresponding resources in vnode
-//static bool tscKillQueryInVnode(SSqlObj* pSql) {
-//  SSqlCmd* pCmd = &pSql->cmd;
-//  SSqlRes* pRes = &pSql->res;
-//
-//  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
-//  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
-//
-//  if (tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
-//    return false;
-//  }
-//
-//  if (pRes->code == TSDB_CODE_SUCCESS && pRes->completed == false && (pSql->pStream == NULL && pTableMetaInfo->pTableMeta != NULL) &&
-//      (pCmd->command == TSDB_SQL_SELECT ||
-//       pCmd->command == TSDB_SQL_SHOW ||
-//       pCmd->command == TSDB_SQL_RETRIEVE ||
-//       pCmd->command == TSDB_SQL_FETCH)) {
-//
-//    pCmd->command = (pCmd->command > TSDB_SQL_MGMT) ? TSDB_SQL_RETRIEVE : TSDB_SQL_FETCH;
-//    tscDebug("%p send msg to dnode to free qhandle ASAP, command:%s, ", pSql, sqlCmd[pCmd->command]);
-//    tscProcessSql(pSql);
-//    return true;
-//  }
-//
-//  return false;
-//}
+static bool tscKillQueryInDnode(SSqlObj* pSql) {
+  SSqlCmd* pCmd = &pSql->cmd;
+  SSqlRes* pRes = &pSql->res;
+
+  if (pRes == NULL || pRes->qhandle == 0) {
+    return true;
+  }
+
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  if ((pQueryInfo == NULL) || tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
+    return true;
+  }
+
+  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  tscRemoveFromSqlList(pSql);
+
+  int32_t cmd = pCmd->command;
+  if (pRes->code == TSDB_CODE_SUCCESS && pRes->completed == false && pSql->pStream == NULL && (pTableMetaInfo->pTableMeta != NULL) &&
+      (cmd == TSDB_SQL_SELECT ||
+       cmd == TSDB_SQL_SHOW ||
+       cmd == TSDB_SQL_RETRIEVE ||
+       cmd == TSDB_SQL_FETCH)) {
+    pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
+    pCmd->command = (pCmd->command > TSDB_SQL_MGMT) ? TSDB_SQL_RETRIEVE : TSDB_SQL_FETCH;
+    tscDebug("%p send msg to dnode to free qhandle ASAP before free sqlObj, command:%s, ", pSql, sqlCmd[pCmd->command]);
+
+    tscProcessSql(pSql);
+    return false;
+  }
+
+  return true;
+}
 
 void taos_free_result(TAOS_RES *res) {
-  if (res == NULL) {
+  SSqlObj* pSql = (SSqlObj*) res;
+  if (pSql == NULL || pSql->signature != pSql) {
+    tscError("%p already released sqlObj", res);
     return;
   }
 
-  SSqlObj* pSql = (SSqlObj*) res;
-  taosCacheRelease(tscObjCache, (void**) &pSql->self, true);
+  assert(pSql->self != 0 && *pSql->self == pSql);
+
+  bool freeNow = tscKillQueryInDnode(pSql);
+  if (freeNow) {
+    tscDebug("%p free sqlObj in cache", pSql);
+    taosCacheRelease(tscObjCache, (void**) &pSql->self, true);
+  }
 }
 
 //static void doFreeResult(TAOS_RES *res) {
@@ -596,7 +611,7 @@ void taos_free_result(TAOS_RES *res) {
 //  }
 //
 //  pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
-//  if (!tscKillQueryInVnode(pSql)) {
+//  if (!tscKillQueryInDnode(pSql)) {
 //    tscFreeSqlObj(pSql);
 //    tscDebug("%p sqlObj is freed by app", pSql);
 //  }
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 47abe60dddcca94929ab5f223306dbf212dda36f..7d4369816a9fcc604adb9427796550fbccf9db2b 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -363,6 +363,7 @@ void tscPartiallyFreeSqlObj(SSqlObj* pSql) {
   
   taosTFree(pSql->pSubs);
   pSql->numOfSubs = 0;
+  pSql->self = 0;
   
   tscResetSqlCmdObj(pCmd, false);
 }
@@ -390,12 +391,36 @@ void tscFreeSqlObjInCache(void *pSql) {
   tscFreeSqlObj(*p);
 }
 
+static UNUSED_FUNC bool tscKillQueryInDnode(SSqlObj* pSql) {
+  SSqlCmd* pCmd = &pSql->cmd;
+  SSqlRes* pRes = &pSql->res;
+
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+
+  if (tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
+    return false;
+  }
+
+  int32_t cmd = pCmd->command;
+  if (pRes->code == TSDB_CODE_SUCCESS && pRes->completed == false && pSql->pStream == NULL && (pTableMetaInfo->pTableMeta != NULL) &&
+      (cmd == TSDB_SQL_SELECT || cmd == TSDB_SQL_SHOW || cmd == TSDB_SQL_RETRIEVE || cmd == TSDB_SQL_FETCH)) {
+    pCmd->command = (pCmd->command > TSDB_SQL_MGMT) ? TSDB_SQL_RETRIEVE : TSDB_SQL_FETCH;
+    tscDebug("%p send msg to dnode to free qhandle ASAP, command:%s, ", pSql, sqlCmd[pCmd->command]);
+    tscProcessSql(pSql);
+    return true;
+  }
+
+  return false;
+}
+
 void tscFreeSqlObj(SSqlObj* pSql) {
   if (pSql == NULL || pSql->signature != pSql) {
     return;
   }
 
-  tscDebug("%p start to free sql object", pSql);
+  tscDebug("%p start to free sqlObj", pSql);
+
   tscFreeSubobj(pSql);
   tscPartiallyFreeSqlObj(pSql);
 
@@ -412,6 +437,7 @@ void tscFreeSqlObj(SSqlObj* pSql) {
   tsem_destroy(&pSql->rspSem);
 
   free(pSql);
+  tscDebug("%p free sqlObj completed", pSql);
 }
 
 void tscDestroyDataBlock(STableDataBlocks* pDataBlock) {
@@ -423,7 +449,10 @@ void tscDestroyDataBlock(STableDataBlocks* pDataBlock) {
   taosTFree(pDataBlock->params);
 
   // free the refcount for metermeta
-  taosCacheRelease(tscCacheHandle, (void**)&(pDataBlock->pTableMeta), false);
+  if (pDataBlock->pTableMeta != NULL) {
+    taosCacheRelease(tscCacheHandle, (void**)&(pDataBlock->pTableMeta), false);
+  }
+
   taosTFree(pDataBlock);
 }
 
@@ -478,7 +507,10 @@ int32_t tscCopyDataBlockToPayload(SSqlObj* pSql, STableDataBlocks* pDataBlock) {
   // set the correct table meta object, the table meta has been locked in pDataBlocks, so it must be in the cache
   if (pTableMetaInfo->pTableMeta != pDataBlock->pTableMeta) {
     tstrncpy(pTableMetaInfo->name, pDataBlock->tableId, sizeof(pTableMetaInfo->name));
-    taosCacheRelease(tscCacheHandle, (void**)&(pTableMetaInfo->pTableMeta), false);
+
+    if (pTableMetaInfo->pTableMeta != NULL) {
+      taosCacheRelease(tscCacheHandle, (void**)&(pTableMetaInfo->pTableMeta), false);
+    }
 
     pTableMetaInfo->pTableMeta = taosCacheTransfer(tscCacheHandle, (void**)&pDataBlock->pTableMeta);
   } else {
@@ -758,6 +790,13 @@ void tscCloseTscObj(STscObj* pObj) {
     if (p == NULL) {
       break;
     }
+
+    tscDebug("%p waiting for sqlObj to be freed, %p", pObj, p);
+    taosMsleep(100);
+
+    // todo fix me!! two threads call taos_free_result will cause problem.
+    tscDebug("%p free :%p", pObj, p);
+    taos_free_result(p);
   }
 
   if (pObj->pDnodeConn != NULL) {
@@ -1703,7 +1742,10 @@ void tscClearTableMetaInfo(STableMetaInfo* pTableMetaInfo, bool removeFromCache)
     return;
   }
 
-  taosCacheRelease(tscCacheHandle, (void**)&(pTableMetaInfo->pTableMeta), removeFromCache);
+  if (pTableMetaInfo->pTableMeta != NULL) {
+    taosCacheRelease(tscCacheHandle, (void**)&(pTableMetaInfo->pTableMeta), removeFromCache);
+  }
+
   taosTFree(pTableMetaInfo->vgroupList);
   
   tscColumnListDestroy(pTableMetaInfo->tagColList);