diff --git a/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md b/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md
index 3c7f6987c72c064810c0666a55bd53511d4f67a4..e0acaee137eb8f4d65e95ae97be7bbc8988cb122 100644
--- a/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md	
+++ b/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md	
@@ -1019,5 +1019,5 @@ SELECT AVG(current),MAX(current),LEASTSQUARES(current, start_val, step_val), PER
 - 表名最大长度为193，每行数据最大长度16k个字符
 - 列名最大长度为65，最多允许1024列，最少需要2列，第一列必须是时间戳
 - 标签最多允许128个，可以0个，标签总长度不超过16k个字符
-- SQL语句最大长度65480个字符，但可通过系统配置参数maxSQLLength修改，最长可配置为8M
+- SQL语句最大长度65480个字符，但可通过系统配置参数maxSQLLength修改，最长可配置为1M
 - 库的数目，超级表的数目、表的数目，系统不做限制，仅受系统资源限制
diff --git a/documentation20/webdocs/markdowndocs/architecture-ch.md b/documentation20/webdocs/markdowndocs/architecture-ch.md
index a279875649503c64861f7b42b64741967f75aa69..460e655f5f9af77b63417eb6f6ba633030ace9d3 100644
--- a/documentation20/webdocs/markdowndocs/architecture-ch.md
+++ b/documentation20/webdocs/markdowndocs/architecture-ch.md
@@ -67,7 +67,7 @@ TDengine 分布式架构的逻辑结构图如下：
 <center> 图 1 TDengine架构示意图  </center>
 一个完整的 TDengine 系统是运行在一到多个物理节点上的，逻辑上，它包含数据节点(dnode)、TDengine客户端(taosc)以及应用(app)。系统中存在一到多个数据节点，这些数据节点组成一个集群(cluster)。应用通过taosc的API与TDengine集群进行互动。下面对每个逻辑单元进行简要介绍。
 
-**物理节点(pnode):** pnode是一独立运行、拥有自己的计算、存储和网络能力的计算机，可以是安装有OS的物理机、虚拟机或容器。物理节点由其配置的 FQDN(Fully Qualified Domain Name)来标识。
+**物理节点(pnode):** pnode是一独立运行、拥有自己的计算、存储和网络能力的计算机，可以是安装有OS的物理机、虚拟机或容器。物理节点由其配置的 FQDN(Fully Qualified Domain Name)来标识。TDengine完全依赖FQDN来进行网络通讯，如果不了解FQDN，请看博文《[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)》。
 
 **数据节点(dnode):** dnode 是 TDengine 服务器侧执行代码 taosd 在物理节点上的一个运行实例，一个工作的系统必须有至少一个数据节点。dnode包含零到多个逻辑的虚拟节点(VNODE)，零或者至多一个逻辑的管理节点(mnode)。dnode在系统中的唯一标识由实例的End Point (EP )决定。EP是dnode所在物理节点的FQDN (Fully Qualified Domain Name)和系统所配置的网络端口号(Port)的组合。通过配置不同的端口，一个物理节点(一台物理机、虚拟机或容器）可以运行多个实例，或有多个数据节点。
 
diff --git a/documentation20/webdocs/markdowndocs/cluster-ch.md b/documentation20/webdocs/markdowndocs/cluster-ch.md
index 193de729ba9ccf9c1efba53520ac2d69f5f51d87..c36819e5c7ba691f6e6da1f2a858df6ba6b8427d 100644
--- a/documentation20/webdocs/markdowndocs/cluster-ch.md
+++ b/documentation20/webdocs/markdowndocs/cluster-ch.md
@@ -2,13 +2,13 @@
 
 多个TDengine服务器，也就是多个taosd的运行实例可以组成一个集群，以保证TDengine的高可靠运行，并提供水平扩展能力。要了解TDengine 2.0的集群管理，需要对集群的基本概念有所了解，请看TDengine 2.0整体架构一章。而且在安装集群之前，先请按照[《立即开始》](https://www.taosdata.com/cn/getting-started20/)一章安装并体验单节点功能。
 
-集群的每个数据节点是由End Point来唯一标识的，End Point是由FQDN(Fully Qualified Domain Name)外加Port组成，比如 h1.taosdata.com:6030。一般FQDN就是服务器的hostname，可通过Linux命令`hostname -f`获取,FQDN配置参考：[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)。端口是这个数据节点对外服务的端口号，缺省是6030，但可以通过taos.cfg里配置参数serverPort进行修改。一个物理节点可能配置了多个hostname, TDengine会自动获取第一个，但也可以通过taos.cfg里配置参数fqdn进行指定。如果习惯IP地址直接访问，可以将参数fqdn设置为本节点的IP地址。
+集群的每个数据节点是由End Point来唯一标识的，End Point是由FQDN(Fully Qualified Domain Name)外加Port组成，比如 h1.taosdata.com:6030。一般FQDN就是服务器的hostname，可通过Linux命令`hostname -f`获取（如何配置FQDN，请参考：[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)）。端口是这个数据节点对外服务的端口号，缺省是6030，但可以通过taos.cfg里配置参数serverPort进行修改。一个物理节点可能配置了多个hostname, TDengine会自动获取第一个，但也可以通过taos.cfg里配置参数fqdn进行指定。如果习惯IP地址直接访问，可以将参数fqdn设置为本节点的IP地址。
 
 TDengine的集群管理极其简单，除添加和删除节点需要人工干预之外，其他全部是自动完成，最大程度的降低了运维的工作量。本章对集群管理的操作做详细的描述。
 
 ## 准备工作
 
-**第零步**：规划集群所有物理节点的FQDN，将规划好的FQDN分别添加到每个物理节点的/etc/hostname；修改每个物理节点的/etc/hosts，将所有集群物理节点的IP与FQDN的对应添加好【如部署了DNS，请联系网络管理员在DNS上做好相关配置】；
+**第零步**：如果没有部署DNS服务，请规划集群所有物理节点的FQDN，然后按照《[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)》里的步骤，将所有集群物理节点的IP与FQDN的对应关系添加好。
 
 **第一步**：如果搭建集群的物理节点中，存有之前的测试数据、装过1.X的版本，或者装过其他版本的TDengine，请先将其删除，并清空所有数据，具体步骤请参考博客[《TDengine多种安装包的安装和卸载》](https://www.taosdata.com/blog/2019/08/09/566.html ) 
 **注意1：**因为FQDN的信息会写进文件，如果之前没有配置或者更改FQDN，且启动了TDengine。请一定在确保数据无用或者备份的前提下，清理一下之前的数据（rm -rf /var/lib/taos/）；
@@ -22,7 +22,8 @@ TDengine的集群管理极其简单，除添加和删除节点需要人工干预
 
 1. 每个物理节点上执行命令`hostname -f`，查看和确认所有节点的hostname是不相同的(应用驱动所在节点无需做此项检查)；
 2. 每个物理节点上执行`ping host`, 其中host是其他物理节点的hostname, 看能否ping通其它物理节点; 如果不能ping通，需要检查网络设置, 或/etc/hosts文件(Windows系统默认路径为C:\Windows\system32\drivers\etc\hosts)，或DNS的配置。如果无法ping通，是无法组成集群的；
-3. 每个数据节点的End Point就是输出的hostname外加端口号，比如h1.taosdata.com:6030
+3. 从应用运行的物理节点，ping taosd运行的数据节点，如果无法ping通，应用是无法连接taosd的，请检查应用所在物理节点的DNS设置或hosts文件；
+4. 每个数据节点的End Point就是输出的hostname外加端口号，比如h1.taosdata.com:6030
 
 **第五步**：修改TDengine的配置文件（所有节点的文件/etc/taos/taos.cfg都需要修改）。假设准备启动的第一个数据节点End Point为 h1.taosdata.com:6030, 其与集群配置相关参数如下：
 
@@ -30,8 +31,8 @@ TDengine的集群管理极其简单，除添加和删除节点需要人工干预
 // firstEp 是每个数据节点首次启动后连接的第一个数据节点
 firstEp               h1.taosdata.com:6030
 
-// 配置本数据节点的FQDN，如果本机只有一个hostname, 无需配置
-fqdn                  h1.taosdata.com
+// 必须配置为本数据节点的FQDN，如果本机只有一个hostname, 可注释掉本配置
+fqdn                  h1.taosdata.com  
 
 // 配置本数据节点的端口号，缺省是6030
 serverPort            6030
@@ -40,7 +41,7 @@ serverPort            6030
 arbitrator            ha.taosdata.com:6042
 ```
 
-一定要修改的参数是firstEp和fqdn, 其他参数可不做任何修改，除非你很清楚为什么要修改。
+一定要修改的参数是firstEp和fqdn。在每个数据节点，firstEp需全部配置成一样，**但fqdn一定要配置成其所在数据节点的值**。其他参数可不做任何修改，除非你很清楚为什么要修改。
 
 **加入到集群中的数据节点dnode，涉及集群相关的下表11项参数必须完全相同，否则不能成功加入到集群中。**
 
@@ -114,6 +115,8 @@ taos>
 
 ## 数据节点管理
 
+上面已经介绍如何从零开始搭建集群。集群组建完后，还可以随时添加新的数据节点进行扩容，或删除数据节点，并检查集群当前状态。
+
 ### 添加数据节点
 
 执行CLI程序taos, 使用root账号登录进系统, 执行:
diff --git a/src/cq/src/cqMain.c b/src/cq/src/cqMain.c
index 758d620e571b387bbbe91101c89da3900019b6e3..d8f68f66a5b22fa2379b55a6a7f303c4e501c058 100644
--- a/src/cq/src/cqMain.c
+++ b/src/cq/src/cqMain.c
@@ -30,10 +30,12 @@
 #include "tlog.h"
 #include "twal.h"
 
-#define cError(...) { if (cqDebugFlag & DEBUG_ERROR) { taosPrintLog("ERROR CQ  ", cqDebugFlag, __VA_ARGS__); }}
-#define cWarn(...)  { if (cqDebugFlag & DEBUG_WARN)  { taosPrintLog("WARN CQ  ", cqDebugFlag, __VA_ARGS__); }}
+#define cFatal(...) { if (cqDebugFlag & DEBUG_FATAL) { taosPrintLog("CQ  FATAL ", 255, __VA_ARGS__); }}
+#define cError(...) { if (cqDebugFlag & DEBUG_ERROR) { taosPrintLog("CQ  ERROR ", 255, __VA_ARGS__); }}
+#define cWarn(...)  { if (cqDebugFlag & DEBUG_WARN)  { taosPrintLog("CQ  WARN ", 255, __VA_ARGS__); }}
+#define cInfo(...)  { if (cqDebugFlag & DEBUG_INFO)  { taosPrintLog("CQ  ", 255, __VA_ARGS__); }}
+#define cDebug(...) { if (cqDebugFlag & DEBUG_DEBUG) { taosPrintLog("CQ  ", cqDebugFlag, __VA_ARGS__); }}
 #define cTrace(...) { if (cqDebugFlag & DEBUG_TRACE) { taosPrintLog("CQ  ", cqDebugFlag, __VA_ARGS__); }}
-#define cPrint(...) { taosPrintLog("CQ  ", 255, __VA_ARGS__); }
 
 typedef struct {
   int      vgId;
@@ -94,7 +96,7 @@ void *cqOpen(void *ahandle, const SCqCfg *pCfg) {
 
   pthread_mutex_init(&pContext->mutex, NULL);
 
-  cTrace("vgId:%d, CQ is opened", pContext->vgId);
+  cInfo("vgId:%d, CQ is opened", pContext->vgId);
 
   return pContext;
 }
@@ -125,7 +127,7 @@ void cqClose(void *handle) {
   taosTmrCleanUp(pContext->tmrCtrl);
   pContext->tmrCtrl = NULL;
 
-  cTrace("vgId:%d, CQ is closed", pContext->vgId);
+  cInfo("vgId:%d, CQ is closed", pContext->vgId);
   free(pContext);
 }
 
@@ -133,7 +135,7 @@ void cqStart(void *handle) {
   SCqContext *pContext = handle;
   if (pContext->dbConn || pContext->master) return;
 
-  cTrace("vgId:%d, start all CQs", pContext->vgId);
+  cInfo("vgId:%d, start all CQs", pContext->vgId);
   pthread_mutex_lock(&pContext->mutex);
 
   pContext->master = 1;
@@ -149,7 +151,7 @@ void cqStart(void *handle) {
 
 void cqStop(void *handle) {
   SCqContext *pContext = handle;
-  cTrace("vgId:%d, stop all CQs", pContext->vgId);
+  cInfo("vgId:%d, stop all CQs", pContext->vgId);
   if (pContext->dbConn == NULL || pContext->master == 0) return;
 
   pthread_mutex_lock(&pContext->mutex);
@@ -160,7 +162,7 @@ void cqStop(void *handle) {
     if (pObj->pStream) {
       taos_close_stream(pObj->pStream);
       pObj->pStream = NULL;
-      cTrace("vgId:%d, id:%d CQ:%s is closed", pContext->vgId, pObj->tid, pObj->sqlStr);
+      cInfo("vgId:%d, id:%d CQ:%s is closed", pContext->vgId, pObj->tid, pObj->sqlStr);
     } else {
       taosTmrStop(pObj->tmrId);
       pObj->tmrId = 0;
@@ -188,7 +190,7 @@ void *cqCreate(void *handle, uint64_t uid, int tid, char *sqlStr, STSchema *pSch
   pObj->pSchema = tdDupSchema(pSchema);
   pObj->rowSize = schemaTLen(pSchema);
 
-  cTrace("vgId:%d, id:%d CQ:%s is created", pContext->vgId, pObj->tid, pObj->sqlStr);
+  cInfo("vgId:%d, id:%d CQ:%s is created", pContext->vgId, pObj->tid, pObj->sqlStr);
 
   pthread_mutex_lock(&pContext->mutex);
 
@@ -228,7 +230,7 @@ void cqDrop(void *handle) {
     pObj->tmrId = 0;
   }
 
-  cTrace("vgId:%d, id:%d CQ:%s is dropped", pContext->vgId, pObj->tid, pObj->sqlStr); 
+  cInfo("vgId:%d, id:%d CQ:%s is dropped", pContext->vgId, pObj->tid, pObj->sqlStr); 
   tdFreeSchema(pObj->pSchema);
   free(pObj->sqlStr);
   free(pObj);
@@ -262,7 +264,7 @@ static void cqCreateStream(SCqContext *pContext, SCqObj *pObj) {
   pObj->pStream = taos_open_stream(pContext->dbConn, pObj->sqlStr, cqProcessStreamRes, 0, pObj, NULL);
   if (pObj->pStream) {
     pContext->num++;
-    cTrace("vgId:%d, id:%d CQ:%s is openned", pContext->vgId, pObj->tid, pObj->sqlStr);
+    cInfo("vgId:%d, id:%d CQ:%s is openned", pContext->vgId, pObj->tid, pObj->sqlStr);
   } else {
     cError("vgId:%d, id:%d CQ:%s, failed to open", pContext->vgId, pObj->tid, pObj->sqlStr);
   }
@@ -278,7 +280,7 @@ static void cqProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row) {
   STSchema   *pSchema = pObj->pSchema;
   if (pObj->pStream == NULL) return;
 
-  cTrace("vgId:%d, id:%d CQ:%s stream result is ready", pContext->vgId, pObj->tid, pObj->sqlStr);
+  cDebug("vgId:%d, id:%d CQ:%s stream result is ready", pContext->vgId, pObj->tid, pObj->sqlStr);
 
   int size = sizeof(SWalHead) + sizeof(SSubmitMsg) + sizeof(SSubmitBlk) + TD_DATA_ROW_HEAD_SIZE + pObj->rowSize;
   char *buffer = calloc(size, 1);
diff --git a/src/plugins/http/src/httpSql.c b/src/plugins/http/src/httpSql.c
index 881fa55fb7b1b37901930775d9d67012e3debe18..883fa574ff19958591051512e717a9b512f3e0ce 100644
--- a/src/plugins/http/src/httpSql.c
+++ b/src/plugins/http/src/httpSql.c
@@ -257,20 +257,20 @@ void httpProcessSingleSqlCallBackImp(void *param, TAOS_RES *result, int unUsedCo
   HttpEncodeMethod *encode = pContext->encodeMethod;
 
   if (code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
-    httpError("context:%p, fd:%d, user:%s, query error, taos:%p, code:%s:inprogress, sqlObj:%p", pContext, pContext->fd,
-              pContext->user, pContext->session->taos, tstrerror(code), (SSqlObj *)result);
+    httpError("context:%p, fd:%d, user:%s, query error, code:%s:inprogress, sqlObj:%p", pContext, pContext->fd,
+              pContext->user, tstrerror(code), (SSqlObj *)result);
     return;
   }
 
   if (code < 0) {
     SSqlObj *pObj = (SSqlObj *)result;
     if (code == TSDB_CODE_TSC_INVALID_SQL) {
-      httpError("context:%p, fd:%d, user:%s, query error, taos:%p, code:%s, sqlObj:%p, error:%s", pContext,
-                pContext->fd, pContext->user, pContext->session->taos, tstrerror(code), pObj, pObj->cmd.payload);
+      httpError("context:%p, fd:%d, user:%s, query error, code:%s, sqlObj:%p, error:%s", pContext,
+                pContext->fd, pContext->user, tstrerror(code), pObj, pObj->cmd.payload);
       httpSendTaosdInvalidSqlErrorResp(pContext, pObj->cmd.payload);
     } else {
-      httpError("context:%p, fd:%d, user:%s, query error, taos:%p, code:%s, sqlObj:%p", pContext, pContext->fd,
-                pContext->user, pContext->session->taos, tstrerror(code), pObj);
+      httpError("context:%p, fd:%d, user:%s, query error, code:%s, sqlObj:%p", pContext, pContext->fd,
+                pContext->user, tstrerror(code), pObj);
       httpSendErrorResp(pContext, code);
     }
     taos_free_result(result);
diff --git a/src/sync/src/syncMain.c b/src/sync/src/syncMain.c
index f96b902efde28c62af194047b64485a8f83c0e45..3f57a8b5cddc8b08de98b412ebe582a507c07d61 100644
--- a/src/sync/src/syncMain.c
+++ b/src/sync/src/syncMain.c
@@ -511,9 +511,9 @@ static SSyncPeer *syncAddPeer(SSyncNode *pNode, const SNodeInfo *pInfo) {
   sInfo("%s, it is configured", pPeer->id);
   int ret = strcmp(pPeer->fqdn, tsNodeFqdn);
   if (pPeer->nodeId == 0 || (ret > 0) || (ret == 0 && pPeer->port > tsSyncPort)) {
-    sDebug("%s, start to check peer connection", pPeer->id);
     int32_t checkMs = 100 + (pNode->vgId * 10) % 100;
-    if (pNode->vgId) checkMs = tsStatusInterval * 2000 + 100;
+    if (pNode->vgId > 1) checkMs = tsStatusInterval * 2000 + checkMs;
+    sDebug("%s, start to check peer connection after %d ms", pPeer->id, checkMs);
     taosTmrReset(syncCheckPeerConnection, checkMs, pPeer, syncTmrCtrl, &pPeer->timer);
   }
 
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index b18f45fca601435ba8e9315f4df835b2af113e4b..a3bc0de2722d333818829bd482a7d11a9f87fc8e 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -2085,6 +2085,8 @@ STimeWindow changeTableGroupByLastrow(STableGroupInfo *groupList) {
       totalNumOfTable++;
       taosArrayPush(pGroup, &keyInfo);
     } else {
+      taosArrayDestroy(pGroup);
+
       taosArrayRemove(groupList->pGroupList, j);
       numOfGroups -= 1;
       j -= 1;
diff --git a/tests/pytest/client/twoClients.py b/tests/pytest/client/twoClients.py
new file mode 100644
index 0000000000000000000000000000000000000000..1a1b36c55438f8ea4050bb804b739be71c570960
--- /dev/null
+++ b/tests/pytest/client/twoClients.py
@@ -0,0 +1,96 @@
+###################################################################
+#           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 os
+import sys
+sys.path.insert(0, os.getcwd())
+from util.log import *
+from util.sql import *
+from util.dnodes import *
+import taos
+
+
+class TwoClients:
+    def initConnection(self):
+        self.host = "127.0.0.1"
+        self.user = "root"
+        self.password = "taosdata"
+        self.config = "/home/xp/git/TDengine/sim/dnode1/cfg"        
+    
+    def run(self):
+        tdDnodes.init("")
+        tdDnodes.setTestCluster(False)
+        tdDnodes.setValgrind(False)
+
+        tdDnodes.stopAll()
+        tdDnodes.deploy(1)
+        tdDnodes.start(1)
+        
+        # first client create a stable and insert data
+        conn1 = taos.connect(self.host, self.user, self.password, self.config)
+        cursor1 = conn1.cursor()
+        cursor1.execute("drop database if exists db")
+        cursor1.execute("create database db")
+        cursor1.execute("use db")
+        cursor1.execute("create table tb (ts timestamp, id int) tags(loc nchar(30))")
+        cursor1.execute("insert into t0 using tb tags('beijing') values(now, 1)")
+
+        # second client alter the table created by cleint
+        conn2 = taos.connect(self.host, self.user, self.password, self.config)
+        cursor2 = conn2.cursor() 
+        cursor2.execute("use db")       
+        cursor2.execute("alter table tb add column name nchar(30)")
+        
+        # first client should not be able to use the origin metadata
+        tdSql.init(cursor1, True)
+        tdSql.error("insert into t0 values(now, 2)")
+
+        # first client should be able to insert data with udpated medadata
+        tdSql.execute("insert into t0 values(now, 2, 'test')")
+        tdSql.query("select * from tb")
+        tdSql.checkRows(2)
+
+        # second client drop the table 
+        cursor2.execute("drop table t0")
+        cursor2.execute("create table t0 using tb tags('beijing')")
+
+        tdSql.execute("insert into t0 values(now, 2, 'test')")
+        tdSql.query("select * from tb")
+        tdSql.checkRows(1)
+
+        # error expected for two clients drop the same cloumn
+        cursor2.execute("alter table tb drop column name")
+        tdSql.error("alter table tb drop column name")
+
+        cursor2.execute("alter table tb add column speed int")
+        tdSql.error("alter table tb add column speed int")
+
+
+        tdSql.execute("alter table tb add column size int")
+        tdSql.query("describe tb")
+        tdSql.checkRows(5)
+        tdSql.checkData(0, 0, "ts")
+        tdSql.checkData(1, 0, "id")
+        tdSql.checkData(2, 0, "speed")
+        tdSql.checkData(3, 0, "size")
+        tdSql.checkData(4, 0, "loc")
+
+
+        cursor1.close()
+        cursor2.close()
+        conn1.close()
+        conn2.close()
+        
+clients = TwoClients()
+clients.initConnection()
+clients.run()
\ No newline at end of file
diff --git a/tests/pytest/fulltest.sh b/tests/pytest/fulltest.sh
index bfa546f92e6850cad1c4c070d149961221e41e22..9ebf1584e224c1bd0732d7e209ffc19db9864399 100755
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@@ -187,6 +187,8 @@ python3 ./test.py -f functions/function_top.py
 #python3 ./test.py -f functions/function_twa.py
 python3 queryCount.py
 python3 ./test.py -f query/queryGroupbyWithInterval.py
+python3 client/twoClients.py
+python3 test.py -f query/queryInterval.py
 
 # tools
 python3 test.py -f tools/taosdemo.py
diff --git a/tests/pytest/query/queryInterval.py b/tests/pytest/query/queryInterval.py
new file mode 100644
index 0000000000000000000000000000000000000000..db2c3fdeec3370779d1452e8a3875e3149f57bee
--- /dev/null
+++ b/tests/pytest/query/queryInterval.py
@@ -0,0 +1,62 @@
+###################################################################
+#           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 tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+        self.ts = 1538548685000
+
+    def run(self):
+        tdSql.prepare()
+
+        tdSql.execute("create table st (ts timestamp, voltage int) tags (loc nchar(30))")
+        tdSql.execute("insert into t0 using st tags('beijing') values(now, 220) (now - 15d, 221) (now - 30d, 225) (now - 35d, 228) (now - 45d, 222)")
+        tdSql.execute("insert into t1 using st tags('shanghai') values(now, 220) (now - 60d, 221) (now - 50d, 225) (now - 40d, 228) (now - 20d, 222)")
+
+        tdSql.query("select avg(voltage) from st interval(1n)")
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 1, 223.0)
+        tdSql.checkData(1, 1, 225.0)
+        tdSql.checkData(2, 1, 220.333333)
+        
+        tdSql.query("select avg(voltage) from st interval(1n, 15d)")
+        tdSql.checkRows(3)
+        tdSql.checkData(0, 1, 224.8)
+        tdSql.checkData(1, 1, 222.666666)
+        tdSql.checkData(2, 1, 220.0)
+
+        tdSql.query("select avg(voltage) from st interval(1n, 15d) group by loc")
+        tdSql.checkRows(6)
+        tdSql.checkData(0, 1, 225.0)
+        tdSql.checkData(1, 1, 223.0)
+        tdSql.checkData(2, 1, 220.0)
+        tdSql.checkData(3, 1, 224.666666)
+        tdSql.checkData(4, 1, 222.0)
+        tdSql.checkData(5, 1, 220.0)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/pytest/util/sql.py b/tests/pytest/util/sql.py
index 7de8efdfe96c2312a7bb844329fb91f770c54180..9abec354c6d58507ff3bcc74d1c0dc03f691440c 100644
--- a/tests/pytest/util/sql.py
+++ b/tests/pytest/util/sql.py
@@ -123,8 +123,8 @@ class TDSql:
 
     def checkData(self, row, col, data):
         self.checkRowCol(row, col) 
-        if self.queryResult[row][col] != data:
-            if str(self.queryResult[row][col]) != str(data):
+        if self.queryResult[row][col] != data:            
+            if str(self.queryResult[row][col]) == str(data):
                 tdLog.info("sql:%s, row:%d col:%d data:%s == expect:%s" %
                             (self.sql, row, col, self.queryResult[row][col], data)) 
                 return
diff --git a/tests/script/general/http/chunked.sim b/tests/script/general/http/chunked.sim
index 8673655d969392873b297c82e8ae4d394ac3b190..6592c761c6ccaea94f385ac72982115c775f01d7 100644
--- a/tests/script/general/http/chunked.sim
+++ b/tests/script/general/http/chunked.sim
@@ -3,7 +3,7 @@ sleep 3000
 system sh/deploy.sh -n dnode1 -i 1
 system sh/cfg.sh -n dnode1 -c wallevel -v 0
 system sh/cfg.sh -n dnode1 -c http -v 1
-system sh/cfg.sh -n dnode1 -c maxSQLLength -v 7340032
+system sh/cfg.sh -n dnode1 -c maxSQLLength -v 340032
 system sh/exec.sh -n dnode1 -s start
 
 sleep 3000