diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 2eff96bac975caa878506e46094445289e5013ad..4e05e1ce4c7fea9719e6249bd4b8ed48e5dce4d4 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -168,6 +168,7 @@ static void tscProcessAsyncRetrieveImpl(void *param, TAOS_RES *tres, int numOfRo
   if (pCmd->command != TSDB_SQL_RETRIEVE_LOCALMERGE && pCmd->command < TSDB_SQL_LOCAL) {
     pCmd->command = (pCmd->command > TSDB_SQL_MGMT) ? TSDB_SQL_RETRIEVE : TSDB_SQL_FETCH;
   }
+
   tscProcessSql(pSql);
 }
 
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 1ae12aaf3dc1ba99cfc3e0b622bc3bb7e93983d0..564d5ae23f75a22a36d6538e56ef5a0f4655f162 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -339,7 +339,7 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcIpSet *pIpSet) {
   }
 
   if (rpcMsg->code != TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
-    rpcMsg->code = (pRes->code == TSDB_CODE_SUCCESS) ? pRes->numOfRows: pRes->code;
+    rpcMsg->code = (pRes->code == TSDB_CODE_SUCCESS)? pRes->numOfRows: pRes->code;
     
     bool shouldFree = tscShouldBeFreed(pSql);
     (*pSql->fp)(pSql->param, pSql, rpcMsg->code);
@@ -476,6 +476,8 @@ int tscBuildFetchMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     int32_t vgIndex = pTableMetaInfo->vgroupIndex;
     
     SVgroupsInfo* pVgroupInfo = pTableMetaInfo->vgroupList;
+    assert(pVgroupInfo->vgroups[vgIndex].vgId > 0 && vgIndex < pTableMetaInfo->vgroupList->numOfVgroups);
+
     pRetrieveMsg->header.vgId = htonl(pVgroupInfo->vgroups[vgIndex].vgId);
   } else {
     STableMeta* pTableMeta = pTableMetaInfo->pTableMeta;
@@ -549,6 +551,7 @@ static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char
       assert(index >= 0);
   
       if (pTableMetaInfo->vgroupList->numOfVgroups > 0) {
+        assert(index < pTableMetaInfo->vgroupList->numOfVgroups);
         pVgroupInfo = &pTableMetaInfo->vgroupList->vgroups[index];
       }
       tscDebug("%p query on stable, vgIndex:%d, numOfVgroups:%d", pSql, index, pTableMetaInfo->vgroupList->numOfVgroups);
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 6ec25aedf98b1f7c898dcb98b4545cf807055e2e..3e0fe0b4bec2c392c48fcbec84508ec5b1d3303a 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2008,7 +2008,7 @@ void tscTryQueryNextVnode(SSqlObj* pSql, __async_cb_func_t fp) {
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   
   int32_t totalVgroups = pTableMetaInfo->vgroupList->numOfVgroups;
-  while (++pTableMetaInfo->vgroupIndex < totalVgroups) {
+  if (++pTableMetaInfo->vgroupIndex < totalVgroups) {
     tscDebug("%p results from vgroup index:%d completed, try next:%d. total vgroups:%d. current numOfRes:%" PRId64, pSql,
              pTableMetaInfo->vgroupIndex - 1, pTableMetaInfo->vgroupIndex, totalVgroups, pRes->numOfClauseTotal);
 
@@ -2044,9 +2044,9 @@ void tscTryQueryNextVnode(SSqlObj* pSql, __async_cb_func_t fp) {
 
     // set the callback function
     pSql->fp = fp;
-    if (tscProcessSql(pSql) != 0) {
-      break;
-    }
+    tscProcessSql(pSql);
+  } else {
+    tscDebug("%p try all %d vnodes, query complete. current numOfRes:%" PRId64, pSql, totalVgroups, pRes->numOfClauseTotal);
   }
 }