diff --git a/Jenkinsfile b/Jenkinsfile
index 6d563d132b30e8c27f8c57f6f03f5d733703d3f3..08b6121f12916a8be712dbc4585f167d4dc679f0 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -118,6 +118,22 @@ pipeline {
             date'''
           }
         }
+       stage('connector'){
+         agent{label "release"}
+         steps{
+            sh'''
+            cd ${WORKSPACE}
+            git checkout develop
+            cd tests/gotest
+            bash batchtest.sh
+            cd ${WORKSPACE}/tests/examples/JDBC/JDBCDemo/
+            mvn clean package assembly:single >/dev/null 
+            java -jar target/jdbcChecker-SNAPSHOT-jar-with-dependencies.jar -host 127.0.0.1
+            cd ${WORKSPACE}/tests/examples/python/PYTHONConnectorChecker
+            python3 PythonChecker.py
+            '''
+         }
+       }
 
       }
     }
diff --git a/documentation20/webdocs/markdowndocs/cluster-ch.md b/documentation20/webdocs/markdowndocs/cluster-ch.md
index 10579df79a2573fef8fdcb16a239580c96ce711a..10c28c284c870d1a522a178beb5303901f079a5a 100644
--- a/documentation20/webdocs/markdowndocs/cluster-ch.md
+++ b/documentation20/webdocs/markdowndocs/cluster-ch.md
@@ -213,8 +213,6 @@ SHOW MNODES;
 
 ## Arbitrator的使用
 
-如果副本数为偶数，当一个vnode group里一半或超过一半的vnode不工作时，是无法从中选出master的。同理，一半或超过一半的mnode不工作时，是无法选出mnode的master的，因为存在“split brain”问题。为解决这个问题，TDengine引入了arbitrator的概念。Arbitrator模拟一个vnode或mnode在工作，但只简单的负责网络连接，不处理任何数据插入或访问。只要包含arbitrator在内，超过半数的vnode或mnode工作，那么该vnode group或mnode组就可以正常的提供数据插入或查询服务。比如对于副本数为2的情形，如果一个节点A离线，但另外一个节点B正常，而且能连接到arbitrator, 那么节点B就能正常工作。
+如果副本数为偶数，当一个vnode group里一半vnode不工作时，是无法从中选出master的。同理，一半mnode不工作时，是无法选出mnode的master的，因为存在“split brain”问题。为解决这个问题，TDengine引入了arbitrator的概念。Arbitrator模拟一个vnode或mnode在工作，但只简单的负责网络连接，不处理任何数据插入或访问。只要包含arbitrator在内，超过半数的vnode或mnode工作，那么该vnode group或mnode组就可以正常的提供数据插入或查询服务。比如对于副本数为2的情形，如果一个节点A离线，但另外一个节点B正常，而且能连接到arbitrator, 那么节点B就能正常工作。
 
-下载最新arbitrator及之前版本的安装包，请点击[安装包下载](https://www.taosdata.com/cn/all-downloads/)，在TDengine Arbitrator Linux一节中，选择适合的版本下载并安装。
-
-TDengine Arbitrator安装包里带有一个执行程序tarbitrator, 找任何一台Linux服务器运行它即可。该程序对系统资源几乎没有要求，只需要保证有网络连接即可。该应用的命令行参数`-p`可以指定其对外服务的端口号，缺省是6042。配置每个taosd实例时，可以在配置文件taos.cfg里将参数arbitrator设置为arbitrator的End Point。如果该参数配置了，当副本数为偶数数，系统将自动连接配置的arbitrator。
+TDengine提供一个执行程序tarbitrator, 找任何一台Linux服务器运行它即可。请点击[安装包下载](https://www.taosdata.com/cn/all-downloads/)，在TDengine Arbitrator Linux一节中，选择适合的版本下载并安装。该程序对系统资源几乎没有要求，只需要保证有网络连接即可。该应用的命令行参数`-p`可以指定其对外服务的端口号，缺省是6042。配置每个taosd实例时，可以在配置文件taos.cfg里将参数arbitrator设置为arbitrator的End Point。如果该参数配置了，当副本数为偶数数，系统将自动连接配置的arbitrator。如果副本数为奇数，即使配置了arbitrator, 系统也不会去建立连接。
diff --git a/src/balance/src/balance.c b/src/balance/src/balance.c
index 0fa4b3f34615aad3fb749d44cb27b3feab10f49c..0e9bb85b25defd169fea8711d3e0b40304500de4 100644
--- a/src/balance/src/balance.c
+++ b/src/balance/src/balance.c
@@ -216,8 +216,8 @@ static bool balanceCheckVgroupReady(SVgObj *pVgroup, SVnodeGid *pRmVnode) {
     SVnodeGid *pVnode = pVgroup->vnodeGid + i;
     if (pVnode == pRmVnode) continue;
 
-    mTrace("vgId:%d, change vgroup status, dnode:%d status:%d", pVgroup->vgId, pVnode->pDnode->dnodeId,
-           pVnode->pDnode->status);
+    mTrace("vgId:%d, check vgroup status, dnode:%d status:%d, vnode role:%s", pVgroup->vgId, pVnode->pDnode->dnodeId,
+           pVnode->pDnode->status, syncRole[pVnode->role]);
     if (pVnode->pDnode->status == TAOS_DN_STATUS_DROPPING) continue;
     if (pVnode->pDnode->status == TAOS_DN_STATUS_OFFLINE) continue;
 
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index e99297ef16907facd8b6c89885140c442de2890d..9730a27ab3a9b192856ca4e7d9237eb460b2d8d8 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -604,7 +604,8 @@ static UNUSED_FUNC bool tscKillQueryInDnode(SSqlObj* pSql) {
     return true;
   }
 
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+
   if ((pQueryInfo == NULL) || tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
     return true;
   }
@@ -718,6 +719,7 @@ static void tscKillSTableQuery(SSqlObj *pSql) {
   SSqlCmd* pCmd = &pSql->cmd;
 
   SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
+
   if (!tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
     return;
   }
@@ -766,6 +768,7 @@ void taos_stop_query(TAOS_RES *res) {
   pSql->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
 
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
+
   if (tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
     assert(pSql->pRpcCtx == NULL);
     tscKillSTableQuery(pSql);
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 1a8ed2e72520625d2b7fed35750994232d761224..e53b58daa27b23f32c4487b38c8de8b3afd7cb7f 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -114,9 +114,9 @@ bool tscIsTwoStageSTableQuery(SQueryInfo* pQueryInfo, int32_t tableIndex) {
   }
   
   // for select query super table, the super table vgroup list can not be null in any cases.
-  if (pQueryInfo->command == TSDB_SQL_SELECT && UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
-//    assert(pTableMetaInfo->vgroupList != NULL);  // if retrieve vgroupInfo failed, the value may be null
-  }
+  // if (pQueryInfo->command == TSDB_SQL_SELECT && UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+  //   assert(pTableMetaInfo->vgroupList != NULL);
+  // }
   
   if ((pQueryInfo->type & TSDB_QUERY_TYPE_FREE_RESOURCE) == TSDB_QUERY_TYPE_FREE_RESOURCE) {
     return false;
diff --git a/src/connector/python/linux/python2/taos/cursor.py b/src/connector/python/linux/python2/taos/cursor.py
index 8c268d8afba2b971709fba6f157abfebdc8dfd1a..37c02d330e856717b5ed0bdac76723cf64d3860b 100644
--- a/src/connector/python/linux/python2/taos/cursor.py
+++ b/src/connector/python/linux/python2/taos/cursor.py
@@ -192,8 +192,10 @@ class TDengineCursor(object):
         buffer = [[] for i in range(len(self._fields))]
         self._rowcount = 0
         while True:
-            block, num_of_fields = CTaosInterface.fetchBlock(
-                self._result, self._fields)
+            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
             if num_of_fields == 0:
                 break
             self._rowcount += num_of_fields
diff --git a/src/connector/python/linux/python3/taos/cursor.py b/src/connector/python/linux/python3/taos/cursor.py
index 3f0f315d3388fcac1c752c847b7fa1c412b06749..ec7a85ee1a3f8cb0cd49aca8c2a4242dca89021e 100644
--- a/src/connector/python/linux/python3/taos/cursor.py
+++ b/src/connector/python/linux/python3/taos/cursor.py
@@ -207,8 +207,10 @@ class TDengineCursor(object):
         buffer = [[] for i in range(len(self._fields))]
         self._rowcount = 0
         while True:
-            block, num_of_fields = CTaosInterface.fetchBlock(
-                self._result, self._fields)
+            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
             if num_of_fields == 0:
                 break
             self._rowcount += num_of_fields
diff --git a/src/connector/python/windows/python2/taos/cursor.py b/src/connector/python/windows/python2/taos/cursor.py
index 7eee3bfc8f8559454f53aa967f5ad0294a1cb2bf..8714fe77cb739f23f79247a41d72aa127b6d6d25 100644
--- a/src/connector/python/windows/python2/taos/cursor.py
+++ b/src/connector/python/windows/python2/taos/cursor.py
@@ -142,6 +142,9 @@ class TDengineCursor(object):
         self._rowcount = 0
         while True:
             block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
             if num_of_fields == 0: break
             self._rowcount += num_of_fields
             for i in range(len(self._fields)):
diff --git a/src/connector/python/windows/python3/taos/cursor.py b/src/connector/python/windows/python3/taos/cursor.py
index 5f5aa4e1d7d9b454132f533a9e84cca2859db735..c2c442b06ee71ae90ec63662886c709e38d4d2ad 100644
--- a/src/connector/python/windows/python3/taos/cursor.py
+++ b/src/connector/python/windows/python3/taos/cursor.py
@@ -142,6 +142,9 @@ class TDengineCursor(object):
         self._rowcount = 0
         while True:
             block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
             if num_of_fields == 0: break
             self._rowcount += num_of_fields
             for i in range(len(self._fields)):
diff --git a/src/dnode/src/dnodeVRead.c b/src/dnode/src/dnodeVRead.c
index f6909e54d41a4ce5936ba4b1b3ff1c79e8766564..e61158ef30dddd6037af36c61be1fd522f8af10b 100644
--- a/src/dnode/src/dnodeVRead.c
+++ b/src/dnode/src/dnodeVRead.c
@@ -189,7 +189,6 @@ void dnodeSendRpcReadRsp(void *pVnode, SReadMsg *pRead, int32_t code) {
 void dnodeDispatchNonRspMsg(void *pVnode, SReadMsg *pRead, int32_t code) {
   rpcFreeCont(pRead->rpcMsg.pCont);
   vnodeRelease(pVnode);
-  return;
 }
 
 static void *dnodeProcessReadQueue(void *param) {
diff --git a/src/inc/vnode.h b/src/inc/vnode.h
index 15ddb6afee7c3ac2914df8133df24f6ef80a0a8a..ed6c232fdb35efbe7733f88a66f847fd221edf91 100644
--- a/src/inc/vnode.h
+++ b/src/inc/vnode.h
@@ -41,6 +41,8 @@ typedef struct {
   SRpcMsg  rpcMsg;
 } SReadMsg;
 
+extern char *vnodeStatus[];
+
 int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg);
 int32_t vnodeDrop(int32_t vgId);
 int32_t vnodeOpen(int32_t vgId, char *rootDir);
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index fc76e3dce39dc2f6eeee3aac19d13f2dc605c1a1..f8f99e22c6f437b1eece0d704c8c4551bc434110 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -111,7 +111,6 @@ void mnodeReleaseConn(SConnObj *pConn) {
 }
 
 SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t port) {
-  uint64_t expireTime = CONN_KEEP_TIME * 1000 + (uint64_t)taosGetTimestampMs();
   SConnObj *pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
   if (pConn == NULL) {
     mDebug("connId:%d, is already destroyed, user:%s ip:%s:%u", connId, user, taosIpStr(ip), port);
@@ -126,7 +125,7 @@ SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t po
   }
 
   // mDebug("connId:%d, is incoming, user:%s ip:%s:%u", connId, pConn->user, taosIpStr(pConn->ip), pConn->port);
-  pConn->lastAccess = expireTime;
+  pConn->lastAccess = CONN_KEEP_TIME * 1000 + (uint64_t)taosGetTimestampMs();
   return pConn;
 }
 
@@ -626,7 +625,7 @@ static int32_t mnodeProcessKillConnectionMsg(SMnodeMsg *pMsg) {
 
   SCMKillConnMsg *pKill = pMsg->rpcMsg.pCont;
   int32_t connId = atoi(pKill->queryId);
-  SConnObj *      pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
+  SConnObj *pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
   if (pConn == NULL) {
     mError("connId:%s, failed to kill, conn not exist", pKill->queryId);
     return TSDB_CODE_MND_INVALID_CONN_ID;
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index f6c2ce29d63212400eef8b1f6d535237af37b57a..3cb8db9fafe4ea8fa985377424152c7d0daecf12 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -7118,6 +7118,7 @@ void qCleanupQueryMgmt(void* pQMgmt) {
 
 void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
   if (pMgmt == NULL) {
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
     return NULL;
   }
 
@@ -7126,6 +7127,7 @@ void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
   SQueryMgmt *pQueryMgmt = pMgmt;
   if (pQueryMgmt->qinfoPool == NULL) {
     qError("QInfo:%p failed to add qhandle into qMgmt, since qMgmt is closed", (void *)qInfo);
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
     return NULL;
   }
 
@@ -7133,6 +7135,7 @@ void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
   if (pQueryMgmt->closed) {
 //    pthread_mutex_unlock(&pQueryMgmt->lock);
     qError("QInfo:%p failed to add qhandle into cache, since qMgmt is colsing", (void *)qInfo);
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
     return NULL;
   } else {
     TSDB_CACHE_PTR_TYPE handleVal = (TSDB_CACHE_PTR_TYPE) qInfo;
diff --git a/src/vnode/src/vnodeMain.c b/src/vnode/src/vnodeMain.c
index a9bcf948b6cb00c25a0b283a0cb63126925abd8c..bc728e86d917c649f1c6eb04e870c0261814a904 100644
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@@ -56,6 +56,14 @@ int     syncGetNodesRole(tsync_h shandle, SNodesRole * cfg) { return 0; }
 void    syncConfirmForward(tsync_h shandle, uint64_t version, int32_t code) {}
 #endif
 
+char* vnodeStatus[] = {
+  "init",
+  "ready",
+  "closing",
+  "updating",
+  "reset"
+};
+
 int32_t vnodeInitResources() {
   int code = syncInit();
   if (code != 0) return code;
@@ -74,6 +82,7 @@ int32_t vnodeInitResources() {
 
 void vnodeCleanupResources() {
   if (tsDnodeVnodesHash != NULL) {
+    vDebug("vnode list is cleanup");
     taosHashCleanup(tsDnodeVnodesHash);
     tsDnodeVnodesHash = NULL;
   }
@@ -84,9 +93,10 @@ void vnodeCleanupResources() {
 int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
   int32_t code;
 
-  SVnodeObj *pTemp = (SVnodeObj *)taosHashGet(tsDnodeVnodesHash, (const char *)&pVnodeCfg->cfg.vgId, sizeof(int32_t));
-  if (pTemp != NULL) {
-    vInfo("vgId:%d, vnode already exist, pVnode:%p", pVnodeCfg->cfg.vgId, pTemp);
+  SVnodeObj *pVnode = vnodeAcquire(pVnodeCfg->cfg.vgId);
+  if (pVnode != NULL) {
+    vDebug("vgId:%d, vnode already exist, refCount:%d pVnode:%p", pVnodeCfg->cfg.vgId, pVnode->refCount, pVnode);
+    vnodeRelease(pVnode);
     return TSDB_CODE_SUCCESS;
   }
 
@@ -143,22 +153,24 @@ int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
     return TSDB_CODE_VND_INIT_FAILED;
   }
 
-  vInfo("vgId:%d, vnode is created, walLevel:%d fsyncPeriod:%d", pVnodeCfg->cfg.vgId, pVnodeCfg->cfg.walLevel, pVnodeCfg->cfg.fsyncPeriod);
+  vInfo("vgId:%d, vnode dir is created, walLevel:%d fsyncPeriod:%d", pVnodeCfg->cfg.vgId, pVnodeCfg->cfg.walLevel,
+        pVnodeCfg->cfg.fsyncPeriod);
   code = vnodeOpen(pVnodeCfg->cfg.vgId, rootDir);
 
   return code;
 }
 
 int32_t vnodeDrop(int32_t vgId) {
-  SVnodeObj **ppVnode = (SVnodeObj **)taosHashGet(tsDnodeVnodesHash, (const char *)&vgId, sizeof(int32_t));
-  if (ppVnode == NULL || *ppVnode == NULL) {
-    vDebug("vgId:%d, failed to drop, vgId not find", vgId);
+  SVnodeObj *pVnode = vnodeAcquire(vgId);
+  if (pVnode == NULL) {
+    vDebug("vgId:%d, failed to drop, vnode not find", vgId);
     return TSDB_CODE_VND_INVALID_VGROUP_ID;
   }
 
-  SVnodeObj *pVnode = *ppVnode;
-  vTrace("vgId:%d, vnode will be dropped, refCount:%d", pVnode->vgId, pVnode->refCount);
+  vInfo("vgId:%d, vnode will be dropped, refCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
   pVnode->dropped = 1;
+
+  vnodeRelease(pVnode);
   vnodeCleanUp(pVnode);
 
   return TSDB_CODE_SUCCESS;
@@ -340,11 +352,11 @@ int32_t vnodeOpen(int32_t vnode, char *rootDir) {
 }
 
 int32_t vnodeClose(int32_t vgId) {
-  SVnodeObj **ppVnode = (SVnodeObj **)taosHashGet(tsDnodeVnodesHash, (const char *)&vgId, sizeof(int32_t));
-  if (ppVnode == NULL || *ppVnode == NULL) return 0;
+  SVnodeObj *pVnode = vnodeAcquire(vgId);
+  if (pVnode == NULL) return 0;
 
-  SVnodeObj *pVnode = *ppVnode;
-  vDebug("vgId:%d, vnode will be closed", pVnode->vgId);
+  vDebug("vgId:%d, vnode will be closed, pVnode:%p", pVnode->vgId, pVnode);
+  vnodeRelease(pVnode);
   vnodeCleanUp(pVnode);
 
   return 0;
@@ -355,21 +367,27 @@ void vnodeRelease(void *pVnodeRaw) {
   int32_t    vgId = pVnode->vgId;
 
   int32_t refCount = atomic_sub_fetch_32(&pVnode->refCount, 1);
+  vTrace("vgId:%d, release vnode, refCount:%d pVnode:%p", vgId, refCount, pVnode);
   assert(refCount >= 0);
 
   if (refCount > 0) {
-    vDebug("vgId:%d, release vnode, refCount:%d", vgId, refCount);
-    if (pVnode->status == TAOS_VN_STATUS_RESET && refCount == 2) 
+    if (pVnode->status == TAOS_VN_STATUS_RESET && refCount == 2) {
       tsem_post(&pVnode->sem);
+    }
     return;
   }
 
-  qCleanupQueryMgmt(pVnode->qMgmt);
-  pVnode->qMgmt = NULL;
+  vDebug("vgId:%d, vnode will be destroyed, refCount:%d pVnode:%p", vgId, refCount, pVnode);
+
+  if (pVnode->qMgmt) {
+    qCleanupQueryMgmt(pVnode->qMgmt);
+    pVnode->qMgmt = NULL;
+  }
 
-  if (pVnode->tsdb)
+  if (pVnode->tsdb) {
     tsdbCloseRepo(pVnode->tsdb, 1);
-  pVnode->tsdb = NULL;
+    pVnode->tsdb = NULL;
+  }
 
   // stop continuous query
   if (pVnode->cq) {
@@ -378,18 +396,21 @@ void vnodeRelease(void *pVnodeRaw) {
     cqClose(cq);
   }
 
-  if (pVnode->wal) 
+  if (pVnode->wal) {
     walClose(pVnode->wal);
-  pVnode->wal = NULL;
+    pVnode->wal = NULL;
+  }
 
-  if (pVnode->wqueue) 
+  if (pVnode->wqueue) {
     dnodeFreeVnodeWqueue(pVnode->wqueue);
-  pVnode->wqueue = NULL;
+    pVnode->wqueue = NULL;
+  }
 
-  if (pVnode->rqueue) 
+  if (pVnode->rqueue) {
     dnodeFreeVnodeRqueue(pVnode->rqueue);
-  pVnode->rqueue = NULL;
- 
+    pVnode->rqueue = NULL;
+  }
+
   taosTFree(pVnode->rootDir);
 
   if (pVnode->dropped) {
@@ -413,22 +434,31 @@ void vnodeRelease(void *pVnodeRaw) {
   free(pVnode);
 
   int32_t count = taosHashGetSize(tsDnodeVnodesHash);
-  vDebug("vgId:%d, vnode is released, vnodes:%d", vgId, count);
+  vDebug("vgId:%d, vnode is destroyed, vnodes:%d", vgId, count);
+}
+
+static void vnodeIncRef(void *ptNode) {
+  assert(ptNode != NULL);
+
+  SVnodeObj **ppVnode = (SVnodeObj **)ptNode;
+  assert(ppVnode);
+  assert(*ppVnode);
+
+  SVnodeObj *pVnode = *ppVnode;
+  atomic_add_fetch_32(&pVnode->refCount, 1);
+  vTrace("vgId:%d, get vnode, refCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
 }
 
 void *vnodeAcquire(int32_t vgId) {
-  SVnodeObj **ppVnode = (SVnodeObj **)taosHashGet(tsDnodeVnodesHash, (const char *)&vgId, sizeof(int32_t));
+  SVnodeObj **ppVnode = taosHashGetCB(tsDnodeVnodesHash, &vgId, sizeof(int32_t), vnodeIncRef, NULL, sizeof(void *));
+
   if (ppVnode == NULL || *ppVnode == NULL) {
     terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
-    vInfo("vgId:%d, not exist", vgId);
+    vDebug("vgId:%d, not exist", vgId);
     return NULL;
   }
 
-  SVnodeObj *pVnode = *ppVnode;
-  atomic_add_fetch_32(&pVnode->refCount, 1);
-  vDebug("vgId:%d, get vnode, refCount:%d", pVnode->vgId, pVnode->refCount);
-
-  return pVnode;
+  return *ppVnode;
 }
 
 void *vnodeAcquireRqueue(int32_t vgId) {
@@ -528,7 +558,7 @@ void vnodeSetAccess(SDMVgroupAccess *pAccess, int32_t numOfVnodes) {
     if (pVnode != NULL) {
       pVnode->accessState = pAccess[i].accessState;
       if (pVnode->accessState != TSDB_VN_ALL_ACCCESS) {
-        vDebug("vgId:%d, access state is set to %d", pAccess[i].vgId, pVnode->accessState)
+        vDebug("vgId:%d, access state is set to %d", pAccess[i].vgId, pVnode->accessState);
       }
       vnodeRelease(pVnode);
     }
@@ -538,11 +568,12 @@ void vnodeSetAccess(SDMVgroupAccess *pAccess, int32_t numOfVnodes) {
 static void vnodeCleanUp(SVnodeObj *pVnode) {
   // remove from hash, so new messages wont be consumed
   taosHashRemove(tsDnodeVnodesHash, (const char *)&pVnode->vgId, sizeof(int32_t));
-  int i = 0;
 
   if (pVnode->status != TAOS_VN_STATUS_INIT) {
     // it may be in updateing or reset state, then it shall wait
-    while (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_CLOSING) != TAOS_VN_STATUS_READY) {
+    int i = 0;
+    while (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_CLOSING) !=
+           TAOS_VN_STATUS_READY) {
       if (++i % 1000 == 0) {
         sched_yield();
       }
@@ -556,7 +587,7 @@ static void vnodeCleanUp(SVnodeObj *pVnode) {
     syncStop(sync);
   }
 
-  vTrace("vgId:%d, vnode will cleanup, refCount:%d", pVnode->vgId, pVnode->refCount);
+  vDebug("vgId:%d, vnode will cleanup, refCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
 
   // release local resources only after cutting off outside connections
   qQueryMgmtNotifyClosed(pVnode->qMgmt);
@@ -613,17 +644,19 @@ static int vnodeResetTsdb(SVnodeObj *pVnode)
   char rootDir[128] = "\0";
   sprintf(rootDir, "%s/tsdb", pVnode->rootDir);
 
-  if (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_RESET) != TAOS_VN_STATUS_READY)
+  if (atomic_val_compare_exchange_8(&pVnode->status, TAOS_VN_STATUS_READY, TAOS_VN_STATUS_RESET) != TAOS_VN_STATUS_READY) {
     return -1;
+  }
 
   void *tsdb = pVnode->tsdb;
   pVnode->tsdb = NULL;
 
   // acquire vnode
-  int32_t refCount = atomic_add_fetch_32(&pVnode->refCount, 1); 
+  int32_t refCount = atomic_add_fetch_32(&pVnode->refCount, 1);
 
-  if (refCount > 2) 
+  if (refCount > 2) {
     tsem_wait(&pVnode->sem);
+  }
 
   // close tsdb, then open tsdb
   tsdbCloseRepo(tsdb, 0);
diff --git a/src/vnode/src/vnodeRead.c b/src/vnode/src/vnodeRead.c
index a86d83cf2d739508487deb35944f6e2dc7c6dff9..11bf569a405ba0f20024bbd584090e0529ef925b 100644
--- a/src/vnode/src/vnodeRead.c
+++ b/src/vnode/src/vnodeRead.c
@@ -39,8 +39,7 @@ void vnodeInitReadFp(void) {
   vnodeProcessReadMsgFp[TSDB_MSG_TYPE_FETCH] = vnodeProcessFetchMsg;
 }
 
-int32_t vnodeProcessRead(void *param, SReadMsg *pReadMsg) {
-  SVnodeObj *pVnode = (SVnodeObj *)param;
+static int32_t vnodeProcessReadImp(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   int msgType = pReadMsg->rpcMsg.msgType;
 
   if (vnodeProcessReadMsgFp[msgType] == NULL) {
@@ -49,16 +48,23 @@ int32_t vnodeProcessRead(void *param, SReadMsg *pReadMsg) {
   }
 
   if (pVnode->status != TAOS_VN_STATUS_READY) {
-    vDebug("vgId:%d, msgType:%s not processed, vnode status is %d", pVnode->vgId, taosMsg[msgType], pVnode->status);
+    vDebug("vgId:%d, msgType:%s not processed, vnode status is %s", pVnode->vgId, taosMsg[msgType],
+           vnodeStatus[pVnode->status]);
     return TSDB_CODE_APP_NOT_READY;
   }
 
   // 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 (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]);
+    return TSDB_CODE_APP_NOT_READY;
+  }
 
-  // TODO: Later, let slave to support query
-  // if (pVnode->syncCfg.replica > 1 && pVnode->role != TAOS_SYNC_ROLE_MASTER) {
   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]);
@@ -68,6 +74,25 @@ int32_t vnodeProcessRead(void *param, SReadMsg *pReadMsg) {
   return (*vnodeProcessReadMsgFp[msgType])(pVnode, pReadMsg);
 }
 
+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;
@@ -175,11 +200,13 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
     // current connect is broken
     if (code == TSDB_CODE_SUCCESS) {
       handle = qRegisterQInfo(pVnode->qMgmt, (uint64_t)pQInfo);
-      if (handle == NULL) {  // failed to register qhandle, todo add error test case
+      if (handle == NULL) {  // failed to register qhandle
+        pRsp->code = terrno;
+        terrno = 0;
         vError("vgId:%d QInfo:%p register qhandle failed, return to app, code:%s", pVnode->vgId, (void *)pQInfo,
                tstrerror(pRsp->code));
-        pRsp->code = TSDB_CODE_QRY_INVALID_QHANDLE;
         qDestroyQueryInfo(pQInfo);  // destroy it directly
+        return pRsp->code;
       } else {
         assert(*handle == pQInfo);
         pRsp->qhandle = htobe64((uint64_t)pQInfo);
diff --git a/src/vnode/src/vnodeWrite.c b/src/vnode/src/vnodeWrite.c
index 0a139f6b81ff4e9d8a8fdbbe31aed0a3d2eb7041..492a396d936b0126c04ef093cfb1a820e3565e79 100644
--- a/src/vnode/src/vnodeWrite.c
+++ b/src/vnode/src/vnodeWrite.c
@@ -202,7 +202,7 @@ int vnodeWriteCqMsgToQueue(void *param, void *data, int type) {
   memcpy(pWal, pHead, size);
 
   atomic_add_fetch_32(&pVnode->refCount, 1);
-  vDebug("CQ: vgId:%d, get vnode wqueue, refCount:%d", pVnode->vgId, pVnode->refCount);
+  vTrace("CQ: vgId:%d, get vnode wqueue, refCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
 
   taosWriteQitem(pVnode->wqueue, type, pSync);
 
@@ -219,7 +219,7 @@ int vnodeWriteToQueue(void *param, void *data, int type) {
   memcpy(pWal, pHead, size);
 
   atomic_add_fetch_32(&pVnode->refCount, 1);
-  vDebug("vgId:%d, get vnode wqueue, refCount:%d", pVnode->vgId, pVnode->refCount);
+  vTrace("vgId:%d, get vnode wqueue, refCount:%d pVnode:%p", pVnode->vgId, pVnode->refCount, pVnode);
 
   taosWriteQitem(pVnode->wqueue, type, pWal);
 
diff --git a/tests/pytest/concurrent_inquiry.py b/tests/pytest/concurrent_inquiry.py
index 2460900891cff4c7f37d4f0c1e782769e0e6b328..39a4cb48fdc22060f63f443a4ac8142cd6a6903e 100644
--- a/tests/pytest/concurrent_inquiry.py
+++ b/tests/pytest/concurrent_inquiry.py
@@ -12,108 +12,105 @@
 # -*- coding: utf-8 -*-
 import threading
 import taos
-
+import sys
 import json
 import time
 import random
 # query sql
 query_sql = [
 # first supertable
-"select count(*) from test.meters where c1 > 50;",
-"select count(*) from test.meters where c2 >= 50 and c2 < 100;",
-"select count(*) from test.meters where c3 != 5;",
+"select count(*) from test.meters ;",
 "select count(*) from test.meters where t3 > 2;",
 "select count(*) from test.meters where ts <> '2020-05-13 10:00:00.002';",
-"select count(*) from test.meters where t7 like 'fi%';",
-"select count(*) from test.meters where t7 like '_econd';",
+"select count(*) from test.meters where t7 like 'taos_1%';",
+"select count(*) from test.meters where t7 like '_____2';",
+"select count(*) from test.meters where t8 like '%思%';",
 "select count(*) from test.meters interval(1n) order by ts desc;",
-"select max(c0) from test.meters group by tbname",
-"select first(*)  from test.meters;",
-"select last(*)  from test.meters;",
+#"select max(c0) from test.meters group by tbname",
+"select first(ts)  from test.meters where t5 >5000 and t5<5100;",
+"select last(ts)  from test.meters where t5 >5000 and t5<5100;",
 "select last_row(*)  from test.meters;",
 "select twa(c1) from test.t1 where ts > 1500000001000  and ts < 1500000101000" ,
-"select avg(c1) from test.meters;",
+"select avg(c1) from test.meters where t5 >5000 and t5<5100;",
 "select bottom(c1, 2) from test.t1;",
 "select diff(c1) from test.t1;",
 "select leastsquares(c1, 1, 1) from test.t1  ;",
-"select max(c1) from test.meters;",
-"select min(c1) from test.meters;",
-"select c1 + c2 * c3 + c1 / c5 + c4 + c2 from test.t1;",
+"select max(c1) from test.meters where t5 >5000 and t5<5100;",
+"select min(c1) from test.meters where t5 >5000 and t5<5100;",
+"select c1 + c2 + c1 / c5 + c4 + c2 from test.t1;",
 "select percentile(c1, 50) from test.t1;",
 "select spread(c1) from test.t1  ;",
 "select stddev(c1) from test.t1;",
-"select sum(c1) from test.meters;",
-"select top(c1, 2) from test.meters;"
-"select twa(c6) from test.t1 where ts > 1500000001000  and ts < 1500000101000" ,
-"select avg(c6) from test.meters;",
-"select bottom(c6, 2) from test.t1;",
-"select diff(c6) from test.t1;",
-"select leastsquares(c6, 1, 1) from test.t1  ;",
-"select max(c6) from test.meters;",
-"select min(c6) from test.meters;",
-"select c6 + c2 * c3 + c6 / c5 + c4 + c2 from test.t1;",
-"select percentile(c6, 50) from test.t1;",
-"select spread(c6) from test.t1  ;",
-"select stddev(c6) from test.t1;",
-"select sum(c6) from test.meters;",
-"select top(c6, 2) from test.meters;",
+"select sum(c1) from test.meters where t5 >5000 and t5<5100;",
+"select top(c1, 2) from test.meters where t5 >5000 and t5<5100;"
+"select twa(c4) from test.t1 where ts > 1500000001000  and ts < 1500000101000" ,
+"select avg(c4) from test.meters where t5 >5000 and t5<5100;",
+"select bottom(c4, 2) from test.t1 where t5 >5000 and t5<5100;",
+"select diff(c4) from test.t1 where t5 >5000 and t5<5100;",
+"select leastsquares(c4, 1, 1) from test.t1  ;",
+"select max(c4) from test.meters where t5 >5000 and t5<5100;",
+"select min(c4) from test.meters where t5 >5000 and t5<5100;",
+"select c5 + c2  + c4 / c5 + c4 + c2 from test.t1 ;",
+"select percentile(c5, 50) from test.t1;",
+"select spread(c5) from test.t1  ;",
+"select stddev(c5) from test.t1 where t5 >5000 and t5<5100;",
+"select sum(c5) from test.meters where t5 >5000 and t5<5100;",
+"select top(c5, 2) from test.meters where t5 >5000 and t5<5100;",
 #all vnode
-"select count(*) from test.meters where t5 >2500 and t5<7500",       
-"select max(c0),avg(c1) from test.meters where t5 >2500 and t5<7500",
-"select sum(c5),avg(c1) from test.meters where t5 >2500 and t5<7500",
-"select max(c0),min(c6) from test.meters where t5 >2500 and t5<7500",
-"select min(c0),avg(c6) from test.meters where t5 >2500 and t5<7500",
+"select count(*) from test.meters where t5 >5000 and t5<5100",       
+"select max(c0),avg(c1) from test.meters where t5 >5000 and t5<5100",
+"select sum(c5),avg(c1) from test.meters where t5 >5000 and t5<5100",
+"select max(c0),min(c5) from test.meters where t5 >5000 and t5<5100",
+"select min(c0),avg(c5) from test.meters where t5 >5000 and t5<5100",
 # second supertable
-"select count(*) from test.meters1 where c1 > 50;",
-"select count(*) from test.meters1 where c2 >= 50 and c2 < 100;",
-"select count(*) from test.meters1 where c3 != 5;",
 "select count(*) from test.meters1 where t3 > 2;",
 "select count(*) from test.meters1 where ts <> '2020-05-13 10:00:00.002';",
-"select count(*) from test.meters1 where t7 like 'fi%';",
-"select count(*) from test.meters1 where t7 like '_econd';",
+"select count(*) from test.meters where t7 like 'taos_1%';",
+"select count(*) from test.meters where t7 like '_____2';",
+"select count(*) from test.meters where t8 like '%思%';",
 "select count(*) from test.meters1 interval(1n) order by ts desc;",
-"select max(c0) from test.meters1 group by tbname",
-"select first(*)  from test.meters1;",
-"select last(*)  from test.meters1;",
-"select last_row(*)  from test.meters1;",
+#"select max(c0) from test.meters1 group by tbname",
+"select first(ts)  from test.meters1 where t5 >5000 and t5<5100;",
+"select last(ts)  from test.meters1 where t5 >5000 and t5<5100;",
+"select last_row(*)  from test.meters1 ;",
 "select twa(c1) from test.m1 where ts > 1500000001000  and ts < 1500000101000" ,
-"select avg(c1) from test.meters1;",
-"select bottom(c1, 2) from test.m1;",
-"select diff(c1) from test.m1;",
+"select avg(c1) from test.meters1 where t5 >5000 and t5<5100;",
+"select bottom(c1, 2) from test.m1 where t5 >5000 and t5<5100;",
+"select diff(c1) from test.m1 ;",
 "select leastsquares(c1, 1, 1) from test.m1  ;",
-"select max(c1) from test.meters1;",
-"select min(c1) from test.meters1;",
-"select c1 + c2 * c3 + c1 / c5 + c3 + c2 from test.m1;",
+"select max(c1) from test.meters1 where t5 >5000 and t5<5100;",
+"select min(c1) from test.meters1 where t5 >5000 and t5<5100;",
+"select c1 + c2 + c1 / c0 + c2 from test.m1 ;",
 "select percentile(c1, 50) from test.m1;",
 "select spread(c1) from test.m1  ;",
 "select stddev(c1) from test.m1;",
-"select sum(c1) from test.meters1;",
-"select top(c1, 2) from test.meters1;",
-"select twa(c6) from test.m1 where ts > 1500000001000  and ts < 1500000101000" ,
-"select avg(c6) from test.meters1;",
-"select bottom(c6, 2) from test.m1;",
-"select diff(c6) from test.m1;",
-"select leastsquares(c6, 1, 1) from test.m1  ;",
-"select max(c6) from test.meters1;",
-"select min(c6) from test.meters1;",
-"select c6 + c2 * c3 + c6 / c5 + c3 + c2 from test.m1;",
-"select percentile(c6, 50) from test.m1;",
-"select spread(c6) from test.m1  ;",
-"select stddev(c6) from test.m1;",
-"select sum(c6) from test.meters1;",
-"select top(c6, 2) from test.meters1;",
-"select count(*) from test.meters1 where t5 >2500 and t5<7500",
+"select sum(c1) from test.meters1 where t5 >5000 and t5<5100;",
+"select top(c1, 2) from test.meters1 where t5 >5000 and t5<5100;",
+"select twa(c5) from test.m1 where ts > 1500000001000  and ts < 1500000101000" ,
+"select avg(c5) from test.meters1 where t5 >5000 and t5<5100;",
+"select bottom(c5, 2) from test.m1;",
+"select diff(c5) from test.m1;",
+"select leastsquares(c5, 1, 1) from test.m1  ;",
+"select max(c5) from test.meters1 where t5 >5000 and t5<5100;",
+"select min(c5) from test.meters1 where t5 >5000 and t5<5100;",
+"select c5 + c2  + c4 / c5  + c0 from test.m1;",
+"select percentile(c4, 50) from test.m1;",
+"select spread(c4) from test.m1  ;",
+"select stddev(c4) from test.m1;",
+"select sum(c4) from test.meters1 where t5 >5100 and t5<5300;",
+"select top(c4, 2) from test.meters1 where t5 >5100 and t5<5300;",
+"select count(*) from test.meters1 where t5 >5100 and t5<5300",
 #all vnode
-"select count(*) from test.meters1 where t5 >2500 and t5<7500",       
-"select max(c0),avg(c1) from test.meters1 where t5 >2500 and t5<7500",
-"select sum(c5),avg(c1) from test.meters1 where t5 >2500 and t5<7500",
-"select max(c0),min(c6) from test.meters1 where t5 >2500 and t5<7500",
-"select min(c0),avg(c6) from test.meters1 where t5 >2500 and t5<7500",
+"select count(*) from test.meters1 where t5 >5100 and t5<5300",       
+"select max(c0),avg(c1) from test.meters1 where t5 >5000 and t5<5100",
+"select sum(c5),avg(c1) from test.meters1 where t5 >5000 and t5<5100",
+"select max(c0),min(c5) from test.meters1 where t5 >5000 and t5<5100",
+"select min(c0),avg(c5) from test.meters1 where t5 >5000 and t5<5100",
 #join 
-"select * from meters,meters1 where meters.ts = meters1.ts and meters.t5 = meters1.t5",
-"select * from meters,meters1 where meters.ts = meters1.ts and meters.t7 = meters1.t7",
-"select * from meters,meters1 where meters.ts = meters1.ts and meters.t8 = meters1.t8",
-"select meters.ts,meters1.c2 from meters,meters1 where meters.ts = meters1.ts and meters.t8 = meters1.t8"
+# "select * from meters,meters1 where meters.ts = meters1.ts and meters.t5 = meters1.t5",
+# "select * from meters,meters1 where meters.ts = meters1.ts and meters.t7 = meters1.t7",
+# "select * from meters,meters1 where meters.ts = meters1.ts and meters.t8 = meters1.t8",
+# "select meters.ts,meters1.c2 from meters,meters1 where meters.ts = meters1.ts and meters.t8 = meters1.t8"
 ]
 
 class ConcurrentInquiry:
@@ -121,7 +118,8 @@ class ConcurrentInquiry:
         self.numOfTherads = 50
         self.ts=1500000001000
         
-
+    def SetThreadsNum(self,num):
+        self.numOfTherads=num
     def query_thread(self,threadID):
         host = "10.211.55.14"
         user = "root"
@@ -142,12 +140,16 @@ class ConcurrentInquiry:
             for i in ran_query_sql:
                 print("Thread %d : %s"% (threadID,i))
                 try:
+                    start = time.time()
                     cl.execute(i)
                     cl.fetchall
+                    end = time.time()
+                    print("time cost :",end-start)
                 except Exception as e:
                     print(
                 "Failure thread%d, sql: %s,exception: %s" %
                 (threadID, str(i),str(e)))
+                    exit(-1)
                     
                 
             print("Thread %d: finishing" % threadID)
@@ -155,9 +157,9 @@ class ConcurrentInquiry:
         
 
     def run(self):
-       
+            
         threads = []
-        for i in range(50):
+        for i in range(self.numOfTherads):
             thread = threading.Thread(target=self.query_thread, args=(i,))
             threads.append(thread)
             thread.start()  
diff --git a/tests/pytest/fulltest.sh b/tests/pytest/fulltest.sh
index fd973b8b7604c9c6b7148a336ca1ac082cd1b548..4b27c42d3875fec5f645e73c3f081ec08329f607 100755
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@@ -149,6 +149,7 @@ python3 ./test.py -f query/queryNullValueTest.py
 python3 ./test.py -f query/queryInsertValue.py
 python3 ./test.py -f query/queryConnection.py
 python3 ./test.py -f query/natualInterval.py
+python3 ./test.py -f query/bug1471.py
 
 #stream
 python3 ./test.py -f stream/metric_1.py
diff --git a/tests/pytest/query/bug1471.py b/tests/pytest/query/bug1471.py
new file mode 100644
index 0000000000000000000000000000000000000000..f1cb0bdcdfbb085410d0001606208e11373687a1
--- /dev/null
+++ b/tests/pytest/query/bug1471.py
@@ -0,0 +1,73 @@
+###################################################################
+#           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 *
+from util.cases import *
+from util.sql import *
+import time
+import threading
+
+
+class myThread(threading.Thread):
+    def __init__(self, conn):
+        threading.Thread.__init__(self)
+        self.event = threading.Event()
+        self.conn = taos.connect(conn._host, port=conn._port, config=conn._config)
+
+    def run(self):
+        cur = self.conn.cursor()
+        self.event.wait()
+        cur.execute("drop database db")
+        cur.close()
+        self.conn.close()
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+    def run(self):
+        for i in range(50):
+            print("round", i)
+            thread = myThread(tdSql.cursor._connection)
+            thread.start()
+
+            tdSql.execute('reset query cache')
+            tdSql.execute('drop database if exists db')
+            tdSql.execute('create database db')
+            tdSql.execute('use db')
+            tdSql.execute("create table car (ts timestamp, s int)")
+            tdSql.execute("insert into car values('2020-10-19 17:00:00', 123)")
+
+            thread.event.set()
+            try:
+                tdSql.query("select s from car where ts = '2020-10-19 17:00:00'")
+            except Exception as e:
+                pass
+            else:
+                tdSql.checkData(0, 0, 123)
+
+            thread.join()
+            time.sleep(0.2)
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())