Merge branch 'develop' into feature/query

2020-12-18 22:18:37 +08:00 · 2020-12-18 22:18:37 +08:00 · 696ee1d9df
parent c4df06e862 1d7a94f4c1
commit 696ee1d9df
44 changed files with 792 additions and 500 deletions
--- a/.appveyor.yml
+++ b/.appveyor.yml
@ -3,6 +3,7 @@ os: Visual Studio 2015
 environment:
  matrix:
    - ARCH: amd64
+    - ARCH: x86

 clone_folder: c:\dev\TDengine
 clone_depth: 1
@ -23,6 +24,7 @@ notifications:
 - provider: Email
  to:
  - sangshuduo@gmail.com
+  
  on_build_success: true
  on_build_failure: true
  on_build_status_changed: true
--- a/documentation20/webdocs/assets/connector.png
+++ b/documentation20/webdocs/assets/connector.png
--- a/documentation20/webdocs/markdowndocs/Getting
+++ b/documentation20/webdocs/markdowndocs/Getting
@ -2,37 +2,7 @@

 ## 快捷安装

-TDengine软件分为服务器、客户端和报警模块三部分，目前2.0版服务器仅能在Linux系统上安装和运行，后续会支持Windows、mac OS等系统。
-
-**应用驱动**
-
-如果应用在Windows和Linux上运行，可使用C/C++/C#/JAVA/Python/Go/Node.js接口连接服务器。如果应用在Mac上运行，目前可以使用RESTful接口连接服务器。
-
-**CPU**
-
-CPU支持X64/ARM64/MIPS64/Alpha64，后续会支持ARM32、RISC-V等CPU架构。用户可根据需求选择通过[源码](https://www.taosdata.com/cn/getting-started/#通过源码安装)或者[安装包](https://www.taosdata.com/cn/getting-started/#通过安装包安装)来安装。
-
-**服务器**
-
-目前TDengine服务器可以运行在以下平台上：
-
-|                | **CentOS**  **6/7/8** | **Ubuntu**  **16/18/20** | **Other Linux** | **统信****UOS** | **银河****/****中标麒麟** | **凝思**  **V60/V80** |
-| -------------- | --------------------- | ------------------------ | --------------- | --------------- | ------------------------- | --------------------- |
-| X64            | ●                     | ●                        |                 | ○               | ●                         | ●                     |
-| 树莓派ARM32    |                       | ●                        | ●               |                 |                           |                       |
-| 龙芯MIPS64     |                       |                          | ●               |                 |                           |                       |
-| 鲲鹏  ARM64    |                       | ○                        | ○               |                 | ●                         |                       |
-| 申威  Alpha64  |                       |                          | ○               | ●               |                           |                       |
-| 飞腾ARM64      |                       | ○优麒麟                  |                 |                 |                           |                       |
-| 海光X64        | ●                     | ●                        | ●               | ○               | ●                         | ●                     |
-| 瑞芯微ARM64/32 |                       |                          | ○               |                 |                           |                       |
-| 全志ARM64/32   |                       |                          | ○               |                 |                           |                       |
-| 炬力ARM64/32   |                       |                          | ○               |                 |                           |                       |
-| TI ARM32       |                       |                          | ○               |                 |                           |                       |
-
- 其中 ● 表示经过官方测试验证， ○ 表示非官方测试验证。
-
-
+TDengine软件分为服务器、客户端和报警模块三部分，目前2.0版服务器仅能在Linux系统上安装和运行，后续会支持Windows、mac OS等系统。客户端可以在Windows或Linux上安装和运行。任何OS的应用也可以选择RESTful接口连接服务器taosd。CPU支持X64/ARM64/MIPS64/Alpha64，后续会支持ARM32、RISC-V等CPU架构。用户可根据需求选择通过[源码](https://www.taosdata.com/cn/getting-started/#通过源码安装)或者[安装包](https://www.taosdata.com/cn/getting-started/#通过安装包安装)来安装。

 ### 通过源码安装

@ -44,28 +14,11 @@ CPU支持X64/ARM64/MIPS64/Alpha64，后续会支持ARM32、RISC-V等CPU架构。

 ### 通过安装包安装

-服务器部分，我们提供三种安装包，您可以根据需要选择。TDengine的安装非常简单，从下载到安装成功仅仅只要几秒钟。
+TDengine的安装非常简单，从下载到安装成功仅仅只要几秒钟。服务端安装包包含客户端和连接器，我们提供三种安装包，您可以根据需要选择：

- TDengine-server-2.0.9.0-Linux-x64.rpm (4.2M)
- TDengine-server-2.0.9.0-Linux-x64.deb (2.7M)
- TDengine-server-2.0.9.0-Linux-x64.tar.gz (4.5M)
-
-
-客户端部分，Linux安装包如下：
-
- TDengine-client-2.0.9.0-Linux-x64.tar.gz(3.0M)
- TDengine-client-2.0.9.0-Windows-x64.exe(2.8M)
- TDengine-client-2.0.9.0-Windows-x86.exe(2.8M)
-
-报警模块的Linux安装包如下（请参考[报警模块的使用方法](https://github.com/taosdata/TDengine/blob/master/alert/README_cn.md)）：
-
- TDengine-alert-2.0.9.0-Linux-x64.tar.gz (8.1M)
-
-目前，TDengine 支持在使用[`systemd`](https://en.wikipedia.org/wiki/Systemd)做进程服务管理的linux系统上安装，用`which systemctl`命令来检测系统中是否存在`systemd`包:
-
-```cmd
-which systemctl
-```
+- TDengine-server-2.0.10.0-Linux-x64.rpm (4.2M)
+- TDengine-server-2.0.10.0-Linux-x64.deb (2.7M)
+- TDengine-server-2.0.10.0-Linux-x64.tar.gz (4.5M)

 具体的安装过程，请参见<a href="https://www.taosdata.com/blog/2019/08/09/566.html">TDengine多种安装包的安装和卸载</a>。

@ -73,13 +26,13 @@ which systemctl

 安装成功后，用户可使用`systemctl`命令来启动TDengine的服务进程。

-```cmd
-systemctl start taosd
+```bash
+$ systemctl start taosd
 ```

 检查服务是否正常工作。
-```cmd
-systemctl status taosd
+```bash
+$ systemctl status taosd
 ```

 如果TDengine服务正常工作，那么您可以通过TDengine的命令行程序`taos`来访问并体验TDengine。  
@ -88,15 +41,24 @@ systemctl status taosd

 - systemctl命令需要 _root_ 权限来运行，如果您非 _root_ 用户，请在命令前添加 sudo
 - 为更好的获得产品反馈，改善产品，TDengine会采集基本的使用信息，但您可以修改系统配置文件taos.cfg里的配置参数telemetryReporting, 将其设为0，就可将其关闭。
+- TDengine采用FQDN(一般就是hostname)作为节点的ID，为保证正常运行，需要给运行taosd的服务器配置好hostname，在客户端应用运行的机器配置好DNS服务或hosts文件，保证FQDN能够解析。
+
+* TDengine 支持在使用[`systemd`](https://en.wikipedia.org/wiki/Systemd)做进程服务管理的linux系统上安装，用`which systemctl`命令来检测系统中是否存在`systemd`包:
+
+  ```bash
+  $ which systemctl
+  ```
+
+  如果系统中不支持systemd，也可以用手动运行 /usr/local/taos/bin/taosd 方式启动 TDengine 服务。
+
  
-如果系统中不支持`systemd`，也可以用手动运行 /usr/local/taos/bin/taosd 方式启动 TDengine 服务。

 ## TDengine命令行程序

 执行TDengine命令行程序，您只要在Linux终端执行`taos`即可。

-```cmd
-taos
+```bash
+$ taos
 ```

 如果TDengine终端连接服务成功，将会打印出欢迎消息和版本信息。如果失败，则会打印错误消息出来（请参考[FAQ](https://www.taosdata.com/cn/faq/)来解决终端连接服务端失败的问题）。TDengine终端的提示符号如下：
@ -136,8 +98,8 @@ Query OK, 2 row(s) in set (0.001700s)

 示例：

-```cmd
-taos -h 192.168.0.1 -s "use db; show tables;"
+```bash
+$ taos -h 192.168.0.1 -s "use db; show tables;"
 ```

 ### 运行SQL命令脚本
@ -159,8 +121,8 @@ taos> source <filename>;

 启动TDengine的服务，在Linux终端执行taosdemo

-```
-> taosdemo
+```bash
+$ taosdemo
 ```

 该命令将在数据库test下面自动创建一张超级表meters，该超级表下有1万张表，表名为"t0" 到"t9999"，每张表有10万条记录，每条记录有 （f1, f2， f3）三个字段，时间戳从"2017-07-14 10:40:00 000" 到"2017-07-14 10:41:39 999"，每张表带有标签areaid和loc, areaid被设置为1到10, loc被设置为"beijing"或者“shanghai"。
@ -171,33 +133,92 @@ taos> source <filename>;

 - 查询超级表下记录总条数：

-```
+```mysql
 taos> select count(*) from test.meters;
 ```

 - 查询10亿条记录的平均值、最大值、最小值等：

-```
+```mysql
 taos> select avg(f1), max(f2), min(f3) from test.meters;
 ```

 - 查询loc="beijing"的记录总条数：

-```
+```mysql
 taos> select count(*) from test.meters where loc="beijing";
 ```

 - 查询areaid=10的所有记录的平均值、最大值、最小值等：

-```
+```mysql
 taos> select avg(f1), max(f2), min(f3) from test.meters where areaid=10;
 ```

 - 对表t10按10s进行平均值、最大值和最小值聚合统计：

-```
+```mysql
 taos> select avg(f1), max(f2), min(f3) from test.t10 interval(10s);
 ```

 **Note:** taosdemo命令本身带有很多选项，配置表的数目、记录条数等等，请执行 `taosdemo --help`详细列出。您可以设置不同参数进行体验。

+
+
+## 客户端和报警模块
+
+如果客户端和服务端运行在不同的电脑上，可以单独安装客户端。Linux和Windows安装包如下：
+
+- TDengine-client-2.0.10.0-Linux-x64.tar.gz(3.0M)
+- TDengine-client-2.0.10.0-Windows-x64.exe(2.8M)
+- TDengine-client-2.0.10.0-Windows-x86.exe(2.8M)
+
+报警模块的Linux安装包如下（请参考[报警模块的使用方法](https://github.com/taosdata/TDengine/blob/master/alert/README_cn.md)）：
+
+- TDengine-alert-2.0.10.0-Linux-x64.tar.gz (8.1M)
+
+  
+
+## **支持平台列表**
+
+### TDengine服务器支持的平台列表
+
+|                | **CentOS**  **6/7/8** | **Ubuntu**  **16/18/20** | **Other Linux** | **统信****UOS** | **银河****/****中标麒麟** | **凝思**  **V60/V80** |
+| -------------- | --------------------- | ------------------------ | --------------- | --------------- | ------------------------- | --------------------- |
+| X64            | ●                     | ●                        |                 | ○               | ●                         | ●                     |
+| 树莓派ARM32    |                       | ●                        | ●               |                 |                           |                       |
+| 龙芯MIPS64     |                       |                          | ●               |                 |                           |                       |
+| 鲲鹏  ARM64    |                       | ○                        | ○               |                 | ●                         |                       |
+| 申威  Alpha64  |                       |                          | ○               | ●               |                           |                       |
+| 飞腾ARM64      |                       | ○优麒麟                  |                 |                 |                           |                       |
+| 海光X64        | ●                     | ●                        | ●               | ○               | ●                         | ●                     |
+| 瑞芯微ARM64/32 |                       |                          | ○               |                 |                           |                       |
+| 全志ARM64/32   |                       |                          | ○               |                 |                           |                       |
+| 炬力ARM64/32   |                       |                          | ○               |                 |                           |                       |
+| TI ARM32       |                       |                          | ○               |                 |                           |                       |
+
+注： ● 表示经过官方测试验证， ○ 表示非官方测试验证。
+
+
+
+### TDengine客户端和连接器支持的平台列表
+
+目前TDengine的连接器可支持的平台广泛，目前包括：X64/X86/ARM64/ARM32/MIPS/Alpha等硬件平台，以及Linux/Win64/Win32等开发环境。
+
+对照矩阵如下：
+
+| **CPU**     | **X64   64bit** |           |           | **X86   32bit** | **ARM64** | **ARM32** | **MIPS **  **龙芯** | **Alpha **  **申威** | **X64 **  **海光** |
+| ----------- | --------------- | --------- | --------- | --------------- | --------- | --------- | ------------------- | -------------------- | ------------------ |
+| **OS**      | **Linux**       | **Win64** | **Win32** | **Win32**       | **Linux** | **Linux** | **Linux**           | **Linux**            | **Linux**          |
+| **C/C++**   | ●               | ●         | ●         | ○               | ●         | ●         | ●                   | ●                    | ●                  |
+| **JDBC**    | ●               | ●         | ●         | ○               | ●         | ●         | ●                   | ●                    | ●                  |
+| **Python**  | ●               | ●         | ●         | ○               | ●         | ●         | ●                   | --                   | ●                  |
+| **Go**      | ●               | ●         | ●         | ○               | ●         | ●         | ○                   | --                   | --                 |
+| **NodeJs**  | ●               | ●         | ○         | ○               | ●         | ●         | ○                   | --                   | --                 |
+| **C#**      | ○               | ●         | ●         | ○               | ○         | ○         | ○                   | --                   | --                 |
+| **RESTful** | ●               | ●         | ●         | ●               | ●         | ●         | ●                   | ●                    | ●                  |
+
+注： ● 表示经过官方测试验证， ○ 表示非官方测试验证。
+
+请跳转到 [连接器 ](https://www.taosdata.com/cn/documentation/connector)查看更详细的信息。
+
--- a/documentation20/webdocs/markdowndocs/TAOS
+++ b/documentation20/webdocs/markdowndocs/TAOS
@ -1039,3 +1039,21 @@ SELECT AVG(current),MAX(current),LEASTSQUARES(current, start_val, step_val), PER
 - 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
+
+
+
+##  TAOS SQL其他约定
+
+**group by的限制**
+
+TAOS  SQL支持对标签、tbname进行group by操作，也支持普通列进行group by，前提是：仅限一列且该列的唯一值小于10万个。
+
+**join操作的限制**
+
+TAOS SQL支持表之间按主键时间戳来join两张表的列，暂不支持两个表之间聚合后的四则运算。
+
+**is not null与不为空的表达式适用范围**
+
+is not null支持所有类型的列。不为空的表达式为 <>""，仅对非数值类型的列适用。
+
+
--- a/documentation20/webdocs/markdowndocs/administrator-ch.md
+++ b/documentation20/webdocs/markdowndocs/administrator-ch.md
@ -80,6 +80,12 @@ TDengine集群的节点数必须大于等于副本数，否则创建表时将报

 TDengine系统后台服务由taosd提供，可以在配置文件taos.cfg里修改配置参数，以满足不同场景的需求。配置文件的缺省位置在/etc/taos目录，可以通过taosd命令行执行参数-c指定配置文件目录。比如taosd -c /home/user来指定配置文件位于/home/user这个目录。

+另外可以使用 “-C” 显示当前服务器配置参数：
+
+```
+taosd -C
+```
+
 下面仅仅列出一些重要的配置参数，更多的参数请看配置文件里的说明。各个参数的详细介绍及作用请看前述章节，而且这些参数的缺省配置都是工作的，一般无需设置。**注意：配置修改后，需要重启*taosd*服务才能生效。**

 - firstEp: taosd启动时，主动连接的集群中首个dnode的end point, 默认值为localhost:6030。
@ -97,6 +103,7 @@ TDengine系统后台服务由taosd提供，可以在配置文件taos.cfg里修
 - telemetryReporting: 是否允许 TDengine 采集和上报基本使用信息，0表示不允许，1表示允许。 默认值：1。
 - stream: 是否启用连续查询（流计算功能），0表示不允许，1表示允许。 默认值：1。
 - queryBufferSize: 为所有并发查询占用保留的内存大小。计算规则可以根据实际应用可能的最大并发数和表的数字相乘，再乘 170 。单位为字节。
+- ratioOfQueryCores: 设置查询线程的最大数量。最小值0 表示只有1个查询线程；最大值2表示最大建立2倍CPU核数的查询线程。默认为1，表示最大和CPU核数相等的查询线程。该值可以为小数，即0.5表示最大建立CPU核数一半的查询线程。

 **注意：**对于端口，TDengine会使用从serverPort起13个连续的TCP和UDP端口号，请务必在防火墙打开。因此如果是缺省配置，需要打开从6030都6042共13个端口，而且必须TCP和UDP都打开。

@ -152,7 +159,13 @@ ALTER DNODE <dnode_id> <config>

 ## 客户端配置 

-TDengine系统的前台交互客户端应用程序为taos，它与taosd共享同一个配置文件taos.cfg。运行taos时，使用参数-c指定配置文件目录，如taos -c /home/cfg，表示使用/home/cfg/目录下的taos.cfg配置文件中的参数，缺省目录是/etc/taos。本节主要说明 taos 客户端应用在配置文件 taos.cfg 文件中使用到的参数。
+TDengine系统的前台交互客户端应用程序为taos，以及应用驱动，它与taosd共享同一个配置文件taos.cfg。运行taos时，使用参数-c指定配置文件目录，如taos -c /home/cfg，表示使用/home/cfg/目录下的taos.cfg配置文件中的参数，缺省目录是/etc/taos。更多taos的使用方法请见[Shell命令行程序](https://www.taosdata.com/cn/documentation/administrator/#_TDengine_Shell命令行程序)。本节主要说明 taos 客户端应用在配置文件 taos.cfg 文件中使用到的参数。
+
+**2.0.10.0 之后版本支持命令行以下参数显示当前客户端参数的配置**
+
+```bash
+taos -C  或  taos --dump-config
+```

 客户端配置参数

@ -215,15 +228,15 @@ TDengine系统的前台交互客户端应用程序为taos，它与taosd共享同
    均是合法的设置东八区时区的格式。

    时区的设置对于查询和写入SQL语句中非Unix时间戳的内容（时间戳字符串、关键词now的解析）产生影响。例如：
-    ```
+    ```sql
    SELECT count(*) FROM table_name WHERE TS<'2019-04-11 12:01:08';
    ```
    在东八区，SQL语句等效于
-    ```
+    ```sql
    SELECT count(*) FROM table_name WHERE TS<1554955268000;
    ```
    在UTC时区，SQL语句等效于
-    ```
+    ```sql
    SELECT count(*) FROM table_name WHERE TS<1554984068000;
    ```
    为了避免使用字符串时间格式带来的不确定性，也可以直接使用Unix时间戳。此外，还可以在SQL语句中使用带有时区的时间戳字符串，例如：RFC3339格式的时间戳字符串，2013-04-12T15:52:01.123+08:00或者ISO-8601格式时间戳字符串2013-04-12T15:52:01.123+0800。上述两个字符串转化为Unix时间戳不受系统所在时区的影响。
@ -239,31 +252,31 @@ TDengine系统的前台交互客户端应用程序为taos，它与taosd共享同

 系统管理员可以在CLI界面里添加、删除用户，也可以修改密码。CLI里SQL语法如下：

-```
+```sql
 CREATE USER <user_name> PASS <'password'>;
 ```

 创建用户，并指定用户名和密码，密码需要用单引号引起来,单引号为英文半角

-```
+```sql
 DROP USER <user_name>;
 ```

 删除用户，限root用户使用

-```
+```sql
 ALTER USER <user_name> PASS <'password'>;
 ```

 修改用户密码, 为避免被转换为小写，密码需要用单引号引用,单引号为英文半角

-```
+```sql
 ALTER USER <user_name> PRIVILEGE <super|write|read>;
 ```

 修改用户权限为：super/write/read，不需要添加单引号

-```
+```mysql
 SHOW USERS;
 ```

@ -316,12 +329,11 @@ taos> DESCRIBE d1001
 ```
 那么可以用如下命令导入数据

-```
+```mysql
 taos> insert into d1001 file '~/data.csv';
 Query OK, 9 row(s) affected (0.004763s)
 ```

-
 **taosdump工具导入**

 TDengine提供了方便的数据库导入导出工具taosdump。用户可以将taosdump从一个系统导出的数据，导入到其他系统中。具体使用方法，请参见博客：<a href='https://www.taosdata.com/blog/2020/03/09/1334.html'>TDengine DUMP工具使用指南</a>
@ -334,7 +346,7 @@ TDengine提供了方便的数据库导入导出工具taosdump。用户可以将t

 如果用户需要导出一个表或一个STable中的数据，可在shell中运行

-```
+```mysql
 select * from <tb_name> >> data.csv;
 ```

@ -348,37 +360,37 @@ TDengine提供了方便的数据库导出工具taosdump。用户可以根据需

 系统管理员可以从CLI查询系统的连接、正在进行的查询、流式计算，并且可以关闭连接、停止正在进行的查询和流式计算。CLI里SQL语法如下：

-```
+```mysql
 SHOW CONNECTIONS;
 ```

 显示数据库的连接，其中一列显示ip:port, 为连接的IP地址和端口号。

-```
+```mysql
 KILL CONNECTION <connection-id>;
 ```

 强制关闭数据库连接，其中的connection-id是SHOW CONNECTIONS中显示的第一列的数字。

-```
+```mysql
 SHOW QUERIES;
 ```

 显示数据查询，其中第一列显示的以冒号隔开的两个数字为query-id，为发起该query应用连接的connection-id和查询次数。

-```
+```mysql
 KILL QUERY <query-id>;
 ```

 强制关闭数据查询，其中query-id是SHOW QUERIES中显示的 connection-id:query-no字串，如“105:2”，拷贝粘贴即可。

-```
+```mysql
 SHOW STREAMS;
 ```

 显示流式计算，其中第一列显示的以冒号隔开的两个数字为stream-id, 为启动该stream应用连接的connection-id和发起stream的次数。

-```
+```mysql
 KILL STREAM <stream-id>;
 ```

--- a/documentation20/webdocs/markdowndocs/cluster-ch.md
+++ b/documentation20/webdocs/markdowndocs/cluster-ch.md
@ -137,6 +137,16 @@ DROP DNODE "fqdn:port";

 其中fqdn是被删除的节点的FQDN，port是其对外服务器的端口号

+<font color=green>**【注意】**</font>
+
+  - 一个数据节点一旦被drop之后，不能重新加入集群。需要将此节点重新部署（清空数据文件夹）。集群在完成drop dnode操作之前，会将该dnode的数据迁移走。
+
+  - 请注意 drop dnode 和 停止taosd进程是两个不同的概念，不要混淆：因为删除dnode之前要执行迁移数据的操作，因此被删除的dnode必须保持在线状态。待删除操作结束之后，才能停止taosd进程。
+
+  - 一个数据节点被drop之后，其他节点都会感知到这个dnodeID的删除操作，任何集群中的节点都不会再接收此dnodeID的请求。
+
+  - dnodeID的是集群自动分配的，不得人工指定。它在生成时递增的，不会重复。
+
 ### 查看数据节点

 执行CLI程序taos,使用root账号登录进TDengine系统，执行：
--- a/documentation20/webdocs/markdowndocs/connector-ch.md
+++ b/documentation20/webdocs/markdowndocs/connector-ch.md
@ -19,7 +19,10 @@ TDengine提供了丰富的应用程序开发接口，其中包括C/C++、C# 、J

 其中 ● 表示经过官方测试验证， ○ 表示非官方测试验证。

-注意：所有执行 SQL 语句的 API，例如 C/C++ Connector 中的 `tao_query`、`taos_query_a`、`taos_subscribe` 等，以及其它语言中与它们对应的API，每次都只能执行一条 SQL 语句，如果实际参数中包含了多条语句，它们的行为是未定义的。
+注意：
+
+* 所有执行 SQL 语句的 API，例如 C/C++ Connector 中的 `tao_query`、`taos_query_a`、`taos_subscribe` 等，以及其它语言中与它们对应的API，每次都只能执行一条 SQL 语句，如果实际参数中包含了多条语句，它们的行为是未定义的。
+* 升级到TDengine到2.0.8.0版本的用户，必须更新JDBC连接TDengine必须升级taos-jdbcdriver到2.0.12及以上。

 ## C/C++ Connector

--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@ -381,6 +381,7 @@ void tscQueueAsyncError(void(*fp), void *param, int32_t code) {
  taosScheduleTask(tscQhandle, &schedMsg);
 }

+
 void tscQueueAsyncRes(SSqlObj *pSql) {
  if (pSql == NULL || pSql->signature != pSql) {
    tscDebug("%p SqlObj is freed, not add into queue async res", pSql);
@ -390,7 +391,10 @@ void tscQueueAsyncRes(SSqlObj *pSql) {
  tscError("%p add into queued async res, code:%s", pSql, tstrerror(pSql->res.code));

  SSqlRes *pRes = &pSql->res;
-  assert(pSql->fp != NULL && pSql->fetchFp != NULL);
+
+  if (pSql->fp == NULL || pSql->fetchFp == NULL){
+    return;
+  }

  pSql->fp = pSql->fetchFp;
  (*pSql->fp)(pSql->param, pSql, pRes->code);
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@ -243,7 +243,7 @@ int tscSendMsgToServer(SSqlObj *pSql) {
  STscObj* pObj = pSql->pTscObj;
  SSqlCmd* pCmd = &pSql->cmd;
  
-  char *pMsg = rpcMallocCont(sizeof(SMsgVersion) + pCmd->payloadLen);
+  char *pMsg = rpcMallocCont(pCmd->payloadLen);
  if (NULL == pMsg) {
    tscError("%p msg:%s malloc failed", pSql, taosMsg[pSql->cmd.msgType]);
    return TSDB_CODE_TSC_OUT_OF_MEMORY;
@ -254,13 +254,12 @@ int tscSendMsgToServer(SSqlObj *pSql) {
    tscDumpMgmtEpSet(pSql);
  }

-  tstrncpy(pMsg, version, sizeof(SMsgVersion));
-  memcpy(pMsg + sizeof(SMsgVersion), pSql->cmd.payload, pSql->cmd.payloadLen);
+  memcpy(pMsg, pSql->cmd.payload, pSql->cmd.payloadLen);

  SRpcMsg rpcMsg = {
      .msgType = pSql->cmd.msgType,
      .pCont   = pMsg,
-      .contLen = pSql->cmd.payloadLen + sizeof(SMsgVersion),
+      .contLen = pSql->cmd.payloadLen,
      .ahandle = (void*)pSql->self,
      .handle  = NULL,
      .code    = 0
@ -2146,6 +2145,10 @@ int tscProcessConnectRsp(SSqlObj *pSql) {
  if (pConnect->epSet.numOfEps > 0) {
    tscEpSetHtons(&pConnect->epSet);
    tscUpdateMgmtEpSet(pSql, &pConnect->epSet);
+
+    for (int i = 0; i < pConnect->epSet.numOfEps; ++i) {
+      tscDebug("%p epSet.fqdn[%d]: %s, pObj:%p", pSql, i, pConnect->epSet.fqdn[i], pObj);
+    }
  } 

  strcpy(pObj->sversion, pConnect->serverVersion);
--- a/src/dnode/src/dnodeMRead.c
+++ b/src/dnode/src/dnodeMRead.c
@ -124,6 +124,8 @@ void dnodeDispatchToMReadQueue(SRpcMsg *pMsg) {
    SMnodeMsg *pRead = mnodeCreateMsg(pMsg);
    taosWriteQitem(tsMReadQueue, TAOS_QTYPE_RPC, pRead);
  }
+
+  rpcFreeCont(pMsg->pCont);
 }

 static void dnodeFreeMReadMsg(SMnodeMsg *pRead) {
--- a/src/dnode/src/dnodeMWrite.c
+++ b/src/dnode/src/dnodeMWrite.c
@ -125,6 +125,8 @@ void dnodeDispatchToMWriteQueue(SRpcMsg *pMsg) {
           taosMsg[pWrite->rpcMsg.msgType], tsMWriteQueue);
    taosWriteQitem(tsMWriteQueue, TAOS_QTYPE_RPC, pWrite);
  }
+
+  rpcFreeCont(pMsg->pCont);
 }

 static void dnodeFreeMWriteMsg(SMnodeMsg *pWrite) {
--- a/src/dnode/src/dnodeShell.c
+++ b/src/dnode/src/dnodeShell.c
@ -127,20 +127,7 @@ static void dnodeProcessMsgFromShell(SRpcMsg *pMsg, SRpcEpSet *pEpSet) {
  } else {}

  if ( dnodeProcessShellMsgFp[pMsg->msgType] ) {
-    SMsgVersion *pMsgVersion = pMsg->pCont;
-    if (taosCheckVersion(pMsgVersion->clientVersion, version, 3) != TSDB_CODE_SUCCESS) {
-      rpcMsg.code = TSDB_CODE_TSC_INVALID_VERSION;
-      rpcSendResponse(&rpcMsg);
-      rpcFreeCont(pMsg->pCont);
-      return; // todo change the error code
-    }
-    pMsg->pCont += sizeof(*pMsgVersion);
-    pMsg->contLen -= sizeof(*pMsgVersion);
-
    (*dnodeProcessShellMsgFp[pMsg->msgType])(pMsg);
-
-    //pMsg->contLen += sizeof(*pMsgVersion);
-    rpcFreeCont(pMsg->pCont - sizeof(*pMsgVersion));
  } else {
    dError("RPC %p, shell msg:%s is not processed", pMsg->handle, taosMsg[pMsg->msgType]);
    rpcMsg.code = TSDB_CODE_DND_MSG_NOT_PROCESSED;
--- a/src/dnode/src/dnodeVRead.c
+++ b/src/dnode/src/dnodeVRead.c
@ -77,6 +77,8 @@ void dnodeDispatchToVReadQueue(SRpcMsg *pMsg) {
    SRpcMsg rpcRsp = {.handle = pMsg->handle, .code = TSDB_CODE_VND_INVALID_VGROUP_ID};
    rpcSendResponse(&rpcRsp);
  }
+
+  rpcFreeCont(pMsg->pCont);
 }

 void *dnodeAllocVQueryQueue(void *pVnode) {
--- a/src/dnode/src/dnodeVWrite.c
+++ b/src/dnode/src/dnodeVWrite.c
@ -102,6 +102,7 @@ void dnodeDispatchToVWriteQueue(SRpcMsg *pRpcMsg) {
  }

  vnodeRelease(pVnode);
+  rpcFreeCont(pRpcMsg->pCont);
 }

 void *dnodeAllocVWriteQueue(void *pVnode) {
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@ -267,6 +267,12 @@ TAOS_DEFINE_ERROR(TSDB_CODE_SYN_NOT_ENABLED,              0, 0x0901, "Sync modul
 TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_VERSION,          0, 0x0902, "Invalid Sync version")
 TAOS_DEFINE_ERROR(TSDB_CODE_SYN_CONFIRM_EXPIRED,          0, 0x0903, "Sync confirm expired")
 TAOS_DEFINE_ERROR(TSDB_CODE_SYN_TOO_MANY_FWDINFO,         0, 0x0904, "Too many sync fwd infos")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_MISMATCHED_PROTOCOL,      0, 0x0905, "Mismatched protocol")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_MISMATCHED_CLUSTERID,     0, 0x0906, "Mismatched clusterId")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_MISMATCHED_SIGNATURE,     0, 0x0907, "Mismatched signature")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_CHECKSUM,         0, 0x0908, "Invalid msg checksum")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_MSGLEN,           0, 0x0909, "Invalid msg length")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_MSGTYPE,          0, 0x090A, "Invalid msg type")

 // wal
 TAOS_DEFINE_ERROR(TSDB_CODE_WAL_APP_ERROR,                0, 0x1000, "Unexpected generic error in wal")
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@ -198,11 +198,6 @@ typedef struct {
  int32_t numOfVnodes;
 } SMsgDesc;

-typedef struct SMsgVersion {
-  char     clientVersion[TSDB_VERSION_LEN];
-  uint32_t crc;
-} SMsgVersion;
-
 typedef struct SMsgHead {
  int32_t contLen;
  int32_t vgId;
--- a/src/inc/tsync.h
+++ b/src/inc/tsync.h
@ -119,10 +119,6 @@ int32_t syncGetNodesRole(int64_t rid, SNodesRole *);
 extern char *syncRole[];

 //global configurable parameters
-extern int32_t  tsMaxSyncNum;
-extern int32_t  tsSyncTcpThreads;
-extern int32_t  tsSyncTimer;
-extern int32_t  tsMaxFwdInfo;
 extern int32_t  sDebugFlag;
 extern char     tsArbitrator[];
 extern uint16_t tsSyncPort;
--- a/src/inc/vnode.h
+++ b/src/inc/vnode.h
@ -48,7 +48,7 @@ typedef struct {
  void *   pVnode;
  SRpcMsg  rpcMsg;
  SRspRet  rspRet;
-  char     reserveForSync[16];
+  char     reserveForSync[24];
  SWalHead pHead[];
 } SVWriteMsg;

--- a/src/kit/shell/inc/shell.h
+++ b/src/kit/shell/inc/shell.h
@ -86,6 +86,6 @@ extern void           set_terminal_mode();
 extern int get_old_terminal_mode(struct termios* tio);
 extern void            reset_terminal_mode();
 extern SShellArguments args;
-extern TAOS_RES*       result;
+extern int64_t         result;

 #endif
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@ -46,7 +46,7 @@ char      CONTINUE_PROMPT[] = "   -> ";
 int       prompt_size = 6;
 #endif

-TAOS_RES *result = NULL;
+int64_t result = 0;
 SShellHistory   history;

 #define DEFAULT_MAX_BINARY_DISPLAY_WIDTH 30
@ -260,6 +260,14 @@ int32_t shellRunCommand(TAOS* con, char* command) {
 }


+void freeResultWithRid(int64_t rid) {
+  SSqlObj* pSql = taosAcquireRef(tscObjRef, rid);
+  if(pSql){
+    taos_free_result(pSql);
+    taosReleaseRef(tscObjRef, rid);
+  }
+}
+
 void shellRunCommandOnServer(TAOS *con, char command[]) {
  int64_t   st, et;
  wordexp_t full_path;
@ -294,18 +302,22 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {

  st = taosGetTimestampUs();

-  TAOS_RES* pSql = taos_query_h(con, command, &result);
+  TAOS_RES* tmpSql = NULL;
+  TAOS_RES* pSql = taos_query_h(con, command, &tmpSql);
  if (taos_errno(pSql)) {
    taos_error(pSql, st);
    return;
  }

+  atomic_store_64(&result, ((SSqlObj*)tmpSql)->self);
+  int64_t oresult = atomic_load_64(&result);
+
  if (regex_match(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
    fprintf(stdout, "Database changed.\n\n");
    fflush(stdout);

-    atomic_store_ptr(&result, 0);
-    taos_free_result(pSql);
+    atomic_store_64(&result, 0);
+    freeResultWithRid(oresult);
    return;
  }

@ -313,8 +325,8 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
    int error_no = 0;
    int numOfRows = shellDumpResult(pSql, fname, &error_no, printMode);
    if (numOfRows < 0) {
-      atomic_store_ptr(&result, 0);
-      taos_free_result(pSql);
+      atomic_store_64(&result, 0);
+      freeResultWithRid(oresult);
      return;
    }

@ -336,8 +348,8 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
    wordfree(&full_path);
  }

-  atomic_store_ptr(&result, 0);
-  taos_free_result(pSql);
+  atomic_store_64(&result, 0);
+  freeResultWithRid(oresult);
 }

 /* Function to do regular expression check */
@ -501,7 +513,7 @@ static int dumpResultToFile(const char* fname, TAOS_RES* tres) {
    row = taos_fetch_row(tres);
  } while( row != NULL);

-  result = NULL;
+  result = 0;
  fclose(fp);

  return numOfRows;
--- a/src/kit/shell/src/shellMain.c
+++ b/src/kit/shell/src/shellMain.c
@ -19,17 +19,33 @@
 #include "tnettest.h"

 pthread_t pid;
+static tsem_t cancelSem;

 void shellQueryInterruptHandler(int signum) {
+  tsem_post(&cancelSem);
+}
+
+void *cancelHandler(void *arg) {
+  while(1) {
+    if (tsem_wait(&cancelSem) != 0) {
+      taosMsleep(10);
+      continue;
+    }
+
 #ifdef LINUX
-  void* pResHandle = atomic_val_compare_exchange_64(&result, result, 0);
-  taos_stop_query(pResHandle);
+    int64_t rid = atomic_val_compare_exchange_64(&result, result, 0);
+    SSqlObj* pSql = taosAcquireRef(tscObjRef, rid);
+    taos_stop_query(pSql);
+    taosReleaseRef(tscObjRef, rid);
 #else
    printf("\nReceive ctrl+c or other signal, quit shell.\n");
    exit(0);
 #endif
  }
  
+  return NULL;
+}
+
 int checkVersion() {
  if (sizeof(int8_t) != 1) {
    printf("taos int8 size is %d(!= 1)", (int)sizeof(int8_t));
@ -105,6 +121,14 @@ int main(int argc, char* argv[]) {
    exit(EXIT_FAILURE);
  }

+  if (tsem_init(&cancelSem, 0, 0) != 0) {
+    printf("failed to create cancel semphore\n");
+    exit(EXIT_FAILURE);
+  }
+
+  pthread_t spid;
+  pthread_create(&spid, NULL, cancelHandler, NULL);
+
  /* Interrupt handler. */
  struct sigaction act;
  memset(&act, 0, sizeof(struct sigaction));
--- a/src/mnode/inc/mnodeSdb.h
+++ b/src/mnode/inc/mnodeSdb.h
@ -59,7 +59,7 @@ typedef struct SSdbRow {
  SMnodeMsg *pMsg;
  int32_t  (*fpReq)(SMnodeMsg *pMsg);
  int32_t  (*fpRsp)(SMnodeMsg *pMsg, int32_t code);
-  char       reserveForSync[16];
+  char       reserveForSync[24];
  SWalHead   pHead[];
 } SSdbRow;

--- a/src/mnode/src/mnodeMnode.c
+++ b/src/mnode/src/mnodeMnode.c
@ -294,6 +294,11 @@ void mnodeGetMnodeEpSetForShell(SRpcEpSet *epSet, bool redirect) {
  *epSet = tsMEpForShell;
  mnodeMnodeUnLock();

+  if (mnodeGetDnodesNum() <= 1) {
+    epSet->numOfEps = 0;
+    return;
+  }
+
  mTrace("vgId:1, mnodes epSet for shell is returned, num:%d inUse:%d", tsMEpForShell.numOfEps, tsMEpForShell.inUse);
  for (int32_t i = 0; i < epSet->numOfEps; ++i) {
    if (redirect && strcmp(epSet->fqdn[i], tsLocalFqdn) == 0 && htons(epSet->port[i]) == tsServerPort) {
--- a/src/query/inc/sql.y
+++ b/src/query/inc/sql.y
@ -346,8 +346,8 @@ create_table_args(A) ::= ifnotexists(U) ids(V) cpxName(Z) AS select(S). {
  A = tSetCreateSQLElems(NULL, NULL, S, TSQL_CREATE_STREAM);
  setSQLInfo(pInfo, A, NULL, TSDB_SQL_CREATE_TABLE);

-  U.n += Z.n;
-  setCreatedTableName(pInfo, &U, &V);
+  V.n += Z.n;
+  setCreatedTableName(pInfo, &V, &U);
 }

 %type column{TAOS_FIELD}
--- a/src/query/src/sql.c
+++ b/src/query/src/sql.c
@ -2428,8 +2428,8 @@ static void yy_reduce(
  yylhsminor.yy538 = tSetCreateSqlElems(NULL, NULL, yymsp[0].minor.yy84, TSQL_CREATE_STREAM);
  setSqlInfo(pInfo, yylhsminor.yy538, NULL, TSDB_SQL_CREATE_TABLE);

-  yymsp[-4].minor.yy0.n += yymsp[-2].minor.yy0.n;
-  setCreatedTableName(pInfo, &yymsp[-4].minor.yy0, &yymsp[-3].minor.yy0);
+  yymsp[-3].minor.yy0.n += yymsp[-2].minor.yy0.n;
+  setCreatedTableName(pInfo, &yymsp[-3].minor.yy0, &yymsp[-4].minor.yy0);
 }
  yymsp[-4].minor.yy538 = yylhsminor.yy538;
        break;
--- a/src/sync/CMakeLists.txt
+++ b/src/sync/CMakeLists.txt
@ -5,12 +5,12 @@ INCLUDE_DIRECTORIES(inc)
 AUX_SOURCE_DIRECTORY(src SRC)
  
 IF (TD_LINUX)
-  LIST(REMOVE_ITEM SRC src/tarbitrator.c)
+  LIST(REMOVE_ITEM SRC src/syncArbitrator.c)
  ADD_LIBRARY(sync ${SRC})
  TARGET_LINK_LIBRARIES(sync tutil pthread common)

-  LIST(APPEND BIN_SRC src/tarbitrator.c)
-  LIST(APPEND BIN_SRC src/taosTcpPool.c)
+  LIST(APPEND BIN_SRC src/syncArbitrator.c)
+  LIST(APPEND BIN_SRC src/syncTcp.c)
  ADD_EXECUTABLE(tarbitrator ${BIN_SRC})
  TARGET_LINK_LIBRARIES(tarbitrator sync common osdetail tutil)

--- a/src/sync/inc/syncInt.h
+++ b/src/sync/inc/syncInt.h
@ -13,12 +13,14 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

-#ifndef TDENGINE_SYNCINT_H
-#define TDENGINE_SYNCINT_H
+#ifndef TDENGINE_SYNC_INT_H
+#define TDENGINE_SYNC_INT_H

 #ifdef __cplusplus
 extern "C" {
 #endif
+#include "syncMsg.h"
+#include "twal.h"

 #define sFatal(...) { if (sDebugFlag & DEBUG_FATAL) { taosPrintLog("SYN FATAL ", sDebugFlag, __VA_ARGS__); }}
 #define sError(...) { if (sDebugFlag & DEBUG_ERROR) { taosPrintLog("SYN ERROR ", sDebugFlag, __VA_ARGS__); }}
@ -27,86 +29,22 @@ extern "C" {
 #define sDebug(...) { if (sDebugFlag & DEBUG_DEBUG) { taosPrintLog("SYN ", sDebugFlag, __VA_ARGS__); }}
 #define sTrace(...) { if (sDebugFlag & DEBUG_TRACE) { taosPrintLog("SYN ", sDebugFlag, __VA_ARGS__); }}

-typedef enum {
-  TAOS_SMSG_SYNC_DATA     = 1,
-  TAOS_SMSG_FORWARD       = 2,
-  TAOS_SMSG_FORWARD_RSP   = 3,
-  TAOS_SMSG_SYNC_REQ      = 4,
-  TAOS_SMSG_SYNC_RSP      = 5,
-  TAOS_SMSG_SYNC_MUST     = 6,
-  TAOS_SMSG_STATUS        = 7,
-  TAOS_SMSG_SYNC_DATA_RSP = 8,
-} ESyncMsgType;
+#define SYNC_TCP_THREADS 2
+#define SYNC_MAX_NUM 2

 #define SYNC_MAX_SIZE (TSDB_MAX_WAL_SIZE + sizeof(SWalHead) + sizeof(SSyncHead) + 16)
 #define SYNC_RECV_BUFFER_SIZE (5*1024*1024)
+
+#define SYNC_MAX_FWDS 512
 #define SYNC_FWD_TIMER 300
-#define SYNC_ROLE_TIMER 10000
-#define SYNC_WAIT_AFTER_CHOOSE_MASTER 3
+#define SYNC_ROLE_TIMER 15000             // ms
+#define SYNC_CHECK_INTERVAL 1             // ms
+#define SYNC_WAIT_AFTER_CHOOSE_MASTER 10  // ms

 #define nodeRole    pNode->peerInfo[pNode->selfIndex]->role
 #define nodeVersion pNode->peerInfo[pNode->selfIndex]->version
 #define nodeSStatus pNode->peerInfo[pNode->selfIndex]->sstatus

-#pragma pack(push, 1)
-
-typedef struct {
-  char     type;        // msg type
-  char     pversion;    // protocol version
-  char     reserved[6]; // not used
-  int32_t  vgId;        // vg ID
-  int32_t  len;         // content length, does not include head
-  // char     cont[];      // message content starts from here
-} SSyncHead;
-
-typedef struct {
-  SSyncHead syncHead;
-  uint16_t  port;
-  uint16_t  tranId;
-  char      fqdn[TSDB_FQDN_LEN];
-  int32_t   sourceId;  // only for arbitrator
-} SFirstPkt;
-
-typedef struct {
-  int8_t   sync;
-  int8_t   reserved;
-  uint16_t tranId;
-} SFirstPktRsp;
-
-typedef struct {
-  int8_t    role;
-  uint64_t  version;
-} SPeerStatus;
-
-typedef struct {
-  int8_t      role;
-  int8_t      ack;
-  int8_t      type;
-  int8_t      reserved[3];
-  uint16_t    tranId;
-  uint64_t    version;
-  SPeerStatus peersStatus[];
-} SPeersStatus;
-
-typedef struct {
-  char      name[TSDB_FILENAME_LEN];
-  uint32_t  magic;
-  uint32_t  index;
-  uint64_t  fversion;
-  int64_t   size;
-} SFileInfo;
-
-typedef struct {
-  int8_t    sync;
-} SFileAck;
-
-typedef struct {
-  uint64_t  version;
-  int32_t   code;
-} SFwdRsp;
-  
-#pragma pack(pop)
-
 typedef struct {
  char *  buffer;
  int32_t bufferSize;
@ -190,7 +128,6 @@ void    syncRestartConnection(SSyncPeer *pPeer);
 void    syncBroadcastStatus(SSyncNode *pNode);
 void    syncAddPeerRef(SSyncPeer *pPeer);
 int32_t syncDecPeerRef(SSyncPeer *pPeer);
-uint16_t syncGenTranId();

 #ifdef __cplusplus
 }
--- a/src/sync/inc/syncMsg.h
+++ b/src/sync/inc/syncMsg.h
@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_SYNC_MSG_H
+#define TDENGINE_SYNC_MSG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+#include "tsync.h"
+
+typedef enum {
+  TAOS_SMSG_START         = 0,
+  TAOS_SMSG_SYNC_DATA     = 1,
+  TAOS_SMSG_SYNC_DATA_RSP = 2,
+  TAOS_SMSG_SYNC_FWD      = 3,
+  TAOS_SMSG_SYNC_FWD_RSP  = 4,
+  TAOS_SMSG_SYNC_REQ      = 5,
+  TAOS_SMSG_SYNC_REQ_RSP  = 6,
+  TAOS_SMSG_SYNC_MUST     = 7,
+  TAOS_SMSG_SYNC_MUST_RSP = 8,
+  TAOS_SMSG_STATUS        = 9,
+  TAOS_SMSG_STATUS_RSP    = 10,
+  TAOS_SMSG_SETUP         = 11,
+  TAOS_SMSG_SETUP_RSP     = 12,
+  TAOS_SMSG_SYNC_FILE     = 13,
+  TAOS_SMSG_SYNC_FILE_RSP = 14,
+  TAOS_SMSG_END           = 15,
+} ESyncMsgType;
+
+typedef enum {
+  SYNC_STATUS_BROADCAST,
+  SYNC_STATUS_BROADCAST_RSP,
+  SYNC_STATUS_SETUP_CONN,
+  SYNC_STATUS_SETUP_CONN_RSP,
+  SYNC_STATUS_EXCHANGE_DATA,
+  SYNC_STATUS_EXCHANGE_DATA_RSP,
+  SYNC_STATUS_CHECK_ROLE,
+  SYNC_STATUS_CHECK_ROLE_RSP
+} ESyncStatusType;
+
+#pragma pack(push, 1)
+
+typedef struct {
+  int8_t   type;       // msg type
+  int8_t   protocol;   // protocol version
+  uint16_t signature;  // fixed value
+  int32_t  code;       //
+  int32_t  cId;        // cluster Id
+  int32_t  vgId;       // vg ID
+  int32_t  len;        // content length, does not include head
+  uint32_t cksum;
+} SSyncHead;
+
+typedef struct {
+  SSyncHead head;
+  uint16_t  port;
+  uint16_t  tranId;
+  int32_t   sourceId;  // only for arbitrator
+  char      fqdn[TSDB_FQDN_LEN];
+} SSyncMsg;
+
+typedef struct {
+  SSyncHead head;
+  int8_t    sync;
+  int8_t    reserved;
+  uint16_t  tranId;
+  int8_t    reserverd[4];
+} SSyncRsp;
+
+typedef struct {
+  int8_t    role;
+  uint64_t  version;
+} SPeerStatus;
+
+typedef struct {
+  SSyncHead   head;
+  int8_t      role;
+  int8_t      ack;
+  int8_t      type;
+  int8_t      reserved[3];
+  uint16_t    tranId;
+  uint64_t    version;
+  SPeerStatus peersStatus[TAOS_SYNC_MAX_REPLICA];
+} SPeersStatus;
+
+typedef struct {
+  SSyncHead head;
+  char      name[TSDB_FILENAME_LEN];
+  uint32_t  magic;
+  uint32_t  index;
+  uint64_t  fversion;
+  int64_t   size;
+} SFileInfo;
+
+typedef struct {
+  SSyncHead head;
+  int8_t    sync;
+} SFileAck;
+
+typedef struct {
+  SSyncHead head;
+  uint64_t  version;
+  int32_t   code;
+} SFwdRsp;
+
+#pragma pack(pop)
+
+#define SYNC_PROTOCOL_VERSION 1
+#define SYNC_SIGNATURE ((uint16_t)(0xCDEF))
+
+extern char *statusType[];
+
+uint16_t syncGenTranId();
+int32_t  syncCheckHead(SSyncHead *pHead);
+
+void syncBuildSyncFwdMsg(SSyncHead *pHead, int32_t vgId, int32_t len);
+void syncBuildSyncFwdRsp(SFwdRsp *pMsg, int32_t vgId, uint64_t version, int32_t code);
+void syncBuildSyncReqMsg(SSyncMsg *pMsg, int32_t vgId);
+void syncBuildSyncDataMsg(SSyncMsg *pMsg, int32_t vgId);
+void syncBuildSyncSetupMsg(SSyncMsg *pMsg, int32_t vgId);
+void syncBuildPeersStatus(SPeersStatus *pMsg, int32_t vgId);
+
+void syncBuildFileAck(SFileAck *pMsg, int32_t vgId);
+void syncBuildFileInfo(SFileInfo *pMsg, int32_t vgId);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // TDENGINE_VNODEPEER_H
--- a/src/sync/inc/taosTcpPool.h
+++ b/src/sync/inc/taosTcpPool.h
@ -13,16 +13,13 @@
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

-#ifndef TDENGINE_TCP_POOL_H
-#define TDENGINE_TCP_POOL_H
+#ifndef TDENGINE_SYNC_TCP_POOL_H
+#define TDENGINE_SYNC_TCP_POOL_H

 #ifdef __cplusplus
 extern "C" {
 #endif

-typedef void *ttpool_h;
-typedef void *tthread_h;
-
 typedef struct {
  int32_t   numOfThreads;
  uint32_t  serverIp;
@ -33,10 +30,10 @@ typedef struct {
  void    (*processIncomingConn)(int32_t fd, uint32_t ip);
 } SPoolInfo;

-ttpool_h taosOpenTcpThreadPool(SPoolInfo *pInfo);
-void     taosCloseTcpThreadPool(ttpool_h);
-void *   taosAllocateTcpConn(void *, void *ahandle, int32_t connFd);
-void     taosFreeTcpConn(void *);
+void *syncOpenTcpThreadPool(SPoolInfo *pInfo);
+void  syncCloseTcpThreadPool(void *);
+void *syncAllocateTcpConn(void *, void *ahandle, int32_t connFd);
+void  syncFreeTcpConn(void *);

 #ifdef __cplusplus
 }
--- a/src/sync/src/syncArbitrator.c
+++ b/src/sync/src/syncArbitrator.c
@ -22,17 +22,17 @@
 #include "tsocket.h"
 #include "tglobal.h"
 #include "taoserror.h"
-#include "taosTcpPool.h"
 #include "twal.h"
 #include "tsync.h"
 #include "syncInt.h"
+#include "syncTcp.h"

 static void    arbSignalHandler(int32_t signum, siginfo_t *sigInfo, void *context);
 static void    arbProcessIncommingConnection(int32_t connFd, uint32_t sourceIp);
 static void    arbProcessBrokenLink(void *param);
 static int32_t arbProcessPeerMsg(void *param, void *buffer);
 static tsem_t  tsArbSem;
-static ttpool_h tsArbTcpPool;
+static void *  tsArbTcpPool;

 typedef struct {
  char    id[TSDB_EP_LEN + 24];
@ -90,7 +90,7 @@ int32_t main(int32_t argc, char *argv[]) {
  info.processBrokenLink = arbProcessBrokenLink;
  info.processIncomingMsg = arbProcessPeerMsg;
  info.processIncomingConn = arbProcessIncommingConnection;
-  tsArbTcpPool = taosOpenTcpThreadPool(&info);
+  tsArbTcpPool = syncOpenTcpThreadPool(&info);

  if (tsArbTcpPool == NULL) {
    sDebug("failed to open TCP thread pool, exit...");
@ -101,8 +101,8 @@ int32_t main(int32_t argc, char *argv[]) {

  tsem_wait(&tsArbSem);

-  taosCloseTcpThreadPool(tsArbTcpPool);
-  sInfo("TAOS arbitrator is shut down\n");
+  syncCloseTcpThreadPool(tsArbTcpPool);
+  sInfo("TAOS arbitrator is shut down");
  closelog();

  return 0;
@ -113,9 +113,9 @@ static void arbProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {
  tinet_ntoa(ipstr, sourceIp);
  sDebug("peer TCP connection from ip:%s", ipstr);

-  SFirstPkt firstPkt;
-  if (taosReadMsg(connFd, &firstPkt, sizeof(firstPkt)) != sizeof(firstPkt)) {
-    sError("failed to read peer first pkt from ip:%s since %s", ipstr, strerror(errno));
+  SSyncMsg msg;
+  if (taosReadMsg(connFd, &msg, sizeof(SSyncMsg)) != sizeof(SSyncMsg)) {
+    sError("failed to read peer sync msg from ip:%s since %s", ipstr, strerror(errno));
    taosCloseSocket(connFd);
    return;
  }
@ -127,9 +127,9 @@ static void arbProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {
    return;
  }

-  firstPkt.fqdn[sizeof(firstPkt.fqdn) - 1] = 0;
-  snprintf(pNode->id, sizeof(pNode->id), "vgId:%d, peer:%s:%d", firstPkt.sourceId, firstPkt.fqdn, firstPkt.port);
-  if (firstPkt.syncHead.vgId) {
+  msg.fqdn[TSDB_FQDN_LEN - 1] = 0;
+  snprintf(pNode->id, sizeof(pNode->id), "vgId:%d, peer:%s:%d", msg.sourceId, msg.fqdn, msg.port);
+  if (msg.head.vgId) {
    sDebug("%s, vgId in head is not zero, close the connection", pNode->id);
    tfree(pNode);
    taosCloseSocket(connFd);
@ -138,7 +138,7 @@ static void arbProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {

  sDebug("%s, arbitrator request is accepted", pNode->id);
  pNode->nodeFd = connFd;
-  pNode->pConn = taosAllocateTcpConn(tsArbTcpPool, pNode, connFd);
+  pNode->pConn = syncAllocateTcpConn(tsArbTcpPool, pNode, connFd);

  return;
 }
@ -156,8 +156,8 @@ static int32_t arbProcessPeerMsg(void *param, void *buffer) {
  int32_t    bytes = 0;
  char *     cont = (char *)buffer;

-  int32_t hlen = taosReadMsg(pNode->nodeFd, &head, sizeof(head));
-  if (hlen != sizeof(head)) {
+  int32_t hlen = taosReadMsg(pNode->nodeFd, &head, sizeof(SSyncHead));
+  if (hlen != sizeof(SSyncHead)) {
    sDebug("%s, failed to read msg, hlen:%d", pNode->id, hlen);
    return -1;
  }
--- a/src/sync/src/syncMain.c
+++ b/src/sync/src/syncMain.c
@ -23,25 +23,18 @@
 #include "tsocket.h"
 #include "tglobal.h"
 #include "taoserror.h"
-#include "taosTcpPool.h"
 #include "tqueue.h"
 #include "twal.h"
 #include "tsync.h"
+#include "syncTcp.h"
 #include "syncInt.h"

-// global configurable
-int32_t tsMaxSyncNum = 2;
-int32_t tsSyncTcpThreads = 2;
-int32_t tsMaxFwdInfo = 512;
-int32_t tsSyncTimer = 1;
+int32_t tsSyncNum = 0;  // number of sync in process in whole system
+char    tsNodeFqdn[TSDB_FQDN_LEN] = {0};

-// module global, not configurable
-int32_t tsSyncNum;  // number of sync in process in whole system
-char    tsNodeFqdn[TSDB_FQDN_LEN];
-
-static ttpool_h tsTcpPool;
+static void *  tsTcpPool = NULL;
 static void *  tsSyncTmrCtrl = NULL;
-static void *   tsVgIdHash;
+static void *  tsVgIdHash = NULL;
 static int32_t tsSyncRefId = -1;

 // local functions
@ -80,36 +73,10 @@ char *syncStatus[] = {
  "invalid"
 };

-typedef enum {
-  SYNC_STATUS_BROADCAST,
-  SYNC_STATUS_BROADCAST_RSP,
-  SYNC_STATUS_SETUP_CONN,
-  SYNC_STATUS_SETUP_CONN_RSP,
-  SYNC_STATUS_EXCHANGE_DATA,
-  SYNC_STATUS_EXCHANGE_DATA_RSP,
-  SYNC_STATUS_CHECK_ROLE,
-  SYNC_STATUS_CHECK_ROLE_RSP
-} ESyncStatusType;
-
-char *statusType[] = {
-  "broadcast",
-  "broadcast-rsp",
-  "setup-conn",
-  "setup-conn-rsp",
-  "exchange-data",
-  "exchange-data-rsp",
-  "check-role",
-  "check-role-rsp"
-};
-
-uint16_t syncGenTranId() {
-  return taosRand() & 0XFFFF;
-}
-
 int32_t syncInit() {
  SPoolInfo info = {0};

-  info.numOfThreads = tsSyncTcpThreads;
+  info.numOfThreads = SYNC_TCP_THREADS;
  info.serverIp = 0;
  info.port = tsSyncPort;
  info.bufferSize = SYNC_MAX_SIZE;
@ -117,7 +84,7 @@ int32_t syncInit() {
  info.processIncomingMsg = syncProcessPeerMsg;
  info.processIncomingConn = syncProcessIncommingConnection;

-  tsTcpPool = taosOpenTcpThreadPool(&info);
+  tsTcpPool = syncOpenTcpThreadPool(&info);
  if (tsTcpPool == NULL) {
    sError("failed to init tcpPool");
    return -1;
@ -126,16 +93,16 @@ int32_t syncInit() {
  tsSyncTmrCtrl = taosTmrInit(1000, 50, 10000, "SYNC");
  if (tsSyncTmrCtrl == NULL) {
    sError("failed to init tmrCtrl");
-    taosCloseTcpThreadPool(tsTcpPool);
+    syncCloseTcpThreadPool(tsTcpPool);
    tsTcpPool = NULL;
    return -1;
  }

  tsVgIdHash = taosHashInit(TSDB_MIN_VNODES, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, HASH_ENTRY_LOCK);
  if (tsVgIdHash == NULL) {
-    sError("failed to init tsVgIdHash");
+    sError("failed to init vgIdHash");
    taosTmrCleanUp(tsSyncTmrCtrl);
-    taosCloseTcpThreadPool(tsTcpPool);
+    syncCloseTcpThreadPool(tsTcpPool);
    tsTcpPool = NULL;
    tsSyncTmrCtrl = NULL;
    return -1;
@ -155,7 +122,7 @@ int32_t syncInit() {

 void syncCleanUp() {
  if (tsTcpPool) {
-    taosCloseTcpThreadPool(tsTcpPool);
+    syncCloseTcpThreadPool(tsTcpPool);
    tsTcpPool = NULL;
  }

@ -236,7 +203,7 @@ int64_t syncStart(const SSyncInfo *pInfo) {
  sInfo("vgId:%d, %d replicas are configured, quorum:%d role:%s", pNode->vgId, pNode->replica, pNode->quorum,
        syncRole[nodeRole]);

-  pNode->pSyncFwds = calloc(sizeof(SSyncFwds) + tsMaxFwdInfo * sizeof(SFwdInfo), 1);
+  pNode->pSyncFwds = calloc(sizeof(SSyncFwds) + SYNC_MAX_FWDS * sizeof(SFwdInfo), 1);
  if (pNode->pSyncFwds == NULL) {
    sError("vgId:%d, no memory to allocate syncFwds", pNode->vgId);
    terrno = TAOS_SYSTEM_ERROR(errno);
@ -336,6 +303,11 @@ int32_t syncReconfig(int64_t rid, const SSyncCfg *pNewCfg) {
      newPeers[i] = pNode->peerInfo[j];
    }

+    if (newPeers[i] == NULL) {
+      sError("vgId:%d, failed to reconfig", pNode->vgId);
+      return TSDB_CODE_SYN_INVALID_CONFIG;
+    }
+
    if ((strcmp(pNewNode->nodeFqdn, tsNodeFqdn) == 0) && (pNewNode->nodePort == tsSyncPort)) {
      pNode->selfIndex = i;
    }
@ -384,21 +356,13 @@ void syncConfirmForward(int64_t rid, uint64_t version, int32_t code) {

  SSyncPeer *pPeer = pNode->pMaster;
  if (pPeer && pNode->quorum > 1) {
-    char msg[sizeof(SSyncHead) + sizeof(SFwdRsp)] = {0};
+    SFwdRsp rsp;
+    syncBuildSyncFwdRsp(&rsp, pNode->vgId, version, code);

-    SSyncHead *pHead = (SSyncHead *)msg;
-    pHead->type = TAOS_SMSG_FORWARD_RSP;
-    pHead->len = sizeof(SFwdRsp);
-
-    SFwdRsp *pFwdRsp = (SFwdRsp *)(msg + sizeof(SSyncHead));
-    pFwdRsp->version = version;
-    pFwdRsp->code = code;
-
-    int32_t msgLen = sizeof(SSyncHead) + sizeof(SFwdRsp);
-    if (taosWriteMsg(pPeer->peerFd, msg, msgLen) == msgLen) {
-      sTrace("%s, forward-rsp is sent, code:%x hver:%" PRIu64, pPeer->id, code, version);
+    if (taosWriteMsg(pPeer->peerFd, &rsp, sizeof(SFwdRsp)) == sizeof(SFwdRsp)) {
+      sTrace("%s, forward-rsp is sent, code:0x%x hver:%" PRIu64, pPeer->id, code, version);
    } else {
-      sDebug("%s, failed to send forward ack, restart", pPeer->id);
+      sDebug("%s, failed to send forward-rsp, restart", pPeer->id);
      syncRestartConnection(pPeer);
    }
  }
@ -509,7 +473,7 @@ static void syncClosePeerConn(SSyncPeer *pPeer) {
  taosClose(pPeer->syncFd);
  if (pPeer->peerFd >= 0) {
    pPeer->peerFd = -1;
-    taosFreeTcpConn(pPeer->pConn);
+    syncFreeTcpConn(pPeer->pConn);
  }
 }

@ -779,7 +743,7 @@ static void syncRestartPeer(SSyncPeer *pPeer) {
  int32_t ret = strcmp(pPeer->fqdn, tsNodeFqdn);
  if (ret > 0 || (ret == 0 && pPeer->port > tsSyncPort)) {
    sDebug("%s, check peer connection in 1000 ms", pPeer->id);
-    taosTmrReset(syncCheckPeerConnection, tsSyncTimer * 1000, pPeer, tsSyncTmrCtrl, &pPeer->timer);
+    taosTmrReset(syncCheckPeerConnection, SYNC_CHECK_INTERVAL, pPeer, tsSyncTmrCtrl, &pPeer->timer);
  }
 }

@ -857,7 +821,7 @@ static void syncRecoverFromMaster(SSyncPeer *pPeer) {
  taosTmrStopA(&pPeer->timer);

  // Ensure the sync of mnode not interrupted
-  if (pNode->vgId != 1 && tsSyncNum >= tsMaxSyncNum) {
+  if (pNode->vgId != 1 && tsSyncNum >= SYNC_MAX_NUM) {
    sInfo("%s, %d syncs are in process, try later", pPeer->id, tsSyncNum);
    taosTmrReset(syncTryRecoverFromMaster, 500 + (pNode->vgId * 10) % 200, pPeer, tsSyncTmrCtrl, &pPeer->timer);
    return;
@ -865,56 +829,42 @@ static void syncRecoverFromMaster(SSyncPeer *pPeer) {

  sDebug("%s, try to sync", pPeer->id);

-  SFirstPkt firstPkt;
-  memset(&firstPkt, 0, sizeof(firstPkt));
-  firstPkt.syncHead.type = TAOS_SMSG_SYNC_REQ;
-  firstPkt.syncHead.vgId = pNode->vgId;
-  firstPkt.syncHead.len = sizeof(firstPkt) - sizeof(SSyncHead);
-  firstPkt.tranId = syncGenTranId();
-  tstrncpy(firstPkt.fqdn, tsNodeFqdn, sizeof(firstPkt.fqdn));
-  firstPkt.port = tsSyncPort;
-  taosTmrReset(syncNotStarted, tsSyncTimer * 1000, pPeer, tsSyncTmrCtrl, &pPeer->timer);
+  SSyncMsg msg;
+  syncBuildSyncReqMsg(&msg, pNode->vgId);

-  if (taosWriteMsg(pPeer->peerFd, &firstPkt, sizeof(firstPkt)) != sizeof(firstPkt)) {
+  taosTmrReset(syncNotStarted, SYNC_CHECK_INTERVAL, pPeer, tsSyncTmrCtrl, &pPeer->timer);
+
+  if (taosWriteMsg(pPeer->peerFd, &msg, sizeof(SSyncMsg)) != sizeof(SSyncMsg)) {
    sError("%s, failed to send sync-req to peer", pPeer->id);
  } else {
-    sInfo("%s, sync-req is sent to peer, tranId:%u, sstatus:%s", pPeer->id, firstPkt.tranId, syncStatus[nodeSStatus]);
+    sInfo("%s, sync-req is sent to peer, tranId:%u, sstatus:%s", pPeer->id, msg.tranId, syncStatus[nodeSStatus]);
  }
 }

-static void syncProcessFwdResponse(char *cont, SSyncPeer *pPeer) {
+static void syncProcessFwdResponse(SFwdRsp *pFwdRsp, SSyncPeer *pPeer) {
  SSyncNode *pNode = pPeer->pSyncNode;
-  SFwdRsp *  pFwdRsp = (SFwdRsp *)cont;
  SSyncFwds *pSyncFwds = pNode->pSyncFwds;
  SFwdInfo * pFwdInfo;

  sTrace("%s, forward-rsp is received, code:%x hver:%" PRIu64, pPeer->id, pFwdRsp->code, pFwdRsp->version);
  SFwdInfo *pFirst = pSyncFwds->fwdInfo + pSyncFwds->first;

-  bool found = false;
  if (pFirst->version <= pFwdRsp->version && pSyncFwds->fwds > 0) {
    // find the forwardInfo from first
    for (int32_t i = 0; i < pSyncFwds->fwds; ++i) {
-      pFwdInfo = pSyncFwds->fwdInfo + (i + pSyncFwds->first) % tsMaxFwdInfo;
+      pFwdInfo = pSyncFwds->fwdInfo + (i + pSyncFwds->first) % SYNC_MAX_FWDS;
      if (pFwdRsp->version == pFwdInfo->version) {
-        found = true;
        syncProcessFwdAck(pNode, pFwdInfo, pFwdRsp->code);
        syncRemoveConfirmedFwdInfo(pNode);
-        break;
+        return;
      }
    }
  }
-
-  if (!found) {
-    sTrace("%s, forward-rsp not found first:%d fwds:%d, code:%x hver:%" PRIu64, pPeer->id, pSyncFwds->first,
-           pSyncFwds->fwds, pFwdRsp->code, pFwdRsp->version);
-    syncProcessFwdAck(pNode, pFwdInfo, pFwdRsp->code);
-  }
 }

 static void syncProcessForwardFromPeer(char *cont, SSyncPeer *pPeer) {
  SSyncNode *pNode = pPeer->pSyncNode;
-  SWalHead * pHead = (SWalHead *)cont;
+  SWalHead * pHead = (SWalHead *)(cont + sizeof(SSyncHead));

  sTrace("%s, forward is received, hver:%" PRIu64 ", len:%d", pPeer->id, pHead->version, pHead->len);

@ -931,9 +881,8 @@ static void syncProcessForwardFromPeer(char *cont, SSyncPeer *pPeer) {
  }
 }

-static void syncProcessPeersStatusMsg(char *cont, SSyncPeer *pPeer) {
+static void syncProcessPeersStatusMsg(SPeersStatus *pPeersStatus, SSyncPeer *pPeer) {
  SSyncNode *pNode = pPeer->pSyncNode;
-  SPeersStatus *pPeersStatus = (SPeersStatus *)cont;

  sDebug("%s, status is received, self:%s:%s:%" PRIu64 ", peer:%s:%" PRIu64 ", ack:%d tranId:%u type:%s pfd:%d",
         pPeer->id, syncRole[nodeRole], syncStatus[nodeSStatus], nodeVersion, syncRole[pPeersStatus->role],
@ -947,23 +896,22 @@ static void syncProcessPeersStatusMsg(char *cont, SSyncPeer *pPeer) {
  }
 }

-static int32_t syncReadPeerMsg(SSyncPeer *pPeer, SSyncHead *pHead, char *cont) {
+static int32_t syncReadPeerMsg(SSyncPeer *pPeer, SSyncHead *pHead) {
  if (pPeer->peerFd < 0) return -1;

  int32_t hlen = taosReadMsg(pPeer->peerFd, pHead, sizeof(SSyncHead));
  if (hlen != sizeof(SSyncHead)) {
-    sDebug("%s, failed to read msg, hlen:%d", pPeer->id, hlen);
+    sDebug("%s, failed to read msg since %s, hlen:%d", pPeer->id, tstrerror(errno), hlen);
    return -1;
  }

-  // head.len = htonl(head.len);
-  if (pHead->len < 0) {
-    sError("%s, invalid pkt length, hlen:%d", pPeer->id, pHead->len);
+  int32_t code = syncCheckHead(pHead);
+  if (code != 0) {
+    sError("%s, failed to check msg head since %s, type:%d", pPeer->id, tstrerror(code), pHead->type);
    return -1;
  }

-  assert(pHead->len <= TSDB_MAX_WAL_SIZE);
-  int32_t bytes = taosReadMsg(pPeer->peerFd, cont, pHead->len);
+  int32_t bytes = taosReadMsg(pPeer->peerFd, (char *)pHead + sizeof(SSyncHead), pHead->len);
  if (bytes != pHead->len) {
    sError("%s, failed to read, bytes:%d len:%d", pPeer->id, bytes, pHead->len);
    return -1;
@ -974,23 +922,22 @@ static int32_t syncReadPeerMsg(SSyncPeer *pPeer, SSyncHead *pHead, char *cont) {

 static int32_t syncProcessPeerMsg(void *param, void *buffer) {
  SSyncPeer *pPeer = param;
-  SSyncHead  head;
-  char *     cont = buffer;
-
+  SSyncHead *pHead = buffer;
  SSyncNode *pNode = pPeer->pSyncNode;
+  
  pthread_mutex_lock(&pNode->mutex);

-  int32_t code = syncReadPeerMsg(pPeer, &head, cont);
+  int32_t code = syncReadPeerMsg(pPeer, pHead);

  if (code == 0) {
-    if (head.type == TAOS_SMSG_FORWARD) {
-      syncProcessForwardFromPeer(cont, pPeer);
-    } else if (head.type == TAOS_SMSG_FORWARD_RSP) {
-      syncProcessFwdResponse(cont, pPeer);
-    } else if (head.type == TAOS_SMSG_SYNC_REQ) {
-      syncProcessSyncRequest(cont, pPeer);
-    } else if (head.type == TAOS_SMSG_STATUS) {
-      syncProcessPeersStatusMsg(cont, pPeer);
+    if (pHead->type == TAOS_SMSG_SYNC_FWD) {
+      syncProcessForwardFromPeer(buffer, pPeer);
+    } else if (pHead->type == TAOS_SMSG_SYNC_FWD_RSP) {
+      syncProcessFwdResponse(buffer, pPeer);
+    } else if (pHead->type == TAOS_SMSG_SYNC_REQ) {
+      syncProcessSyncRequest(buffer, pPeer);
+    } else if (pHead->type == TAOS_SMSG_STATUS) {
+      syncProcessPeersStatusMsg(buffer, pPeer);
    }
  }

@ -999,36 +946,30 @@ static int32_t syncProcessPeerMsg(void *param, void *buffer) {
  return code;
 }

-#define statusMsgLen sizeof(SSyncHead) + sizeof(SPeersStatus) + sizeof(SPeerStatus) * TAOS_SYNC_MAX_REPLICA
-
 static void syncSendPeersStatusMsgToPeer(SSyncPeer *pPeer, char ack, int8_t type, uint16_t tranId) {
-  SSyncNode *pNode = pPeer->pSyncNode;
-  char       msg[statusMsgLen] = {0};
-
  if (pPeer->peerFd < 0 || pPeer->ip == 0) return;

-  SSyncHead *   pHead = (SSyncHead *)msg;
-  SPeersStatus *pPeersStatus = (SPeersStatus *)(msg + sizeof(SSyncHead));
+  SSyncNode *  pNode = pPeer->pSyncNode;
+  SPeersStatus msg;

-  pHead->type = TAOS_SMSG_STATUS;
-  pHead->len = statusMsgLen - sizeof(SSyncHead);
+  memset(&msg, 0, sizeof(SPeersStatus));
+  syncBuildPeersStatus(&msg, pNode->vgId);

-  pPeersStatus->version = nodeVersion;
-  pPeersStatus->role = nodeRole;
-  pPeersStatus->ack = ack;
-  pPeersStatus->type = type;
-  pPeersStatus->tranId = tranId;
+  msg.role = nodeRole;
+  msg.ack = ack;
+  msg.type = type;
+  msg.tranId = tranId;
+  msg.version = nodeVersion;

  for (int32_t i = 0; i < pNode->replica; ++i) {
-    pPeersStatus->peersStatus[i].role = pNode->peerInfo[i]->role;
-    pPeersStatus->peersStatus[i].version = pNode->peerInfo[i]->version;
+    msg.peersStatus[i].role = pNode->peerInfo[i]->role;
+    msg.peersStatus[i].version = pNode->peerInfo[i]->version;
  }

-  if (taosWriteMsg(pPeer->peerFd, msg, statusMsgLen) == statusMsgLen) {
+  if (taosWriteMsg(pPeer->peerFd, &msg, sizeof(SPeersStatus)) == sizeof(SPeersStatus)) {
    sDebug("%s, status is sent, self:%s:%s:%" PRIu64 ", peer:%s:%s:%" PRIu64 ", ack:%d tranId:%u type:%s pfd:%d",
           pPeer->id, syncRole[nodeRole], syncStatus[nodeSStatus], nodeVersion, syncRole[pPeer->role],
-           syncStatus[pPeer->sstatus], pPeer->version, pPeersStatus->ack, pPeersStatus->tranId,
-           statusType[pPeersStatus->type], pPeer->peerFd);
+           syncStatus[pPeer->sstatus], pPeer->version, ack, tranId, statusType[type], pPeer->peerFd);
  } else {
    sDebug("%s, failed to send status msg, restart", pPeer->id);
    syncRestartConnection(pPeer);
@ -1048,29 +989,23 @@ static void syncSetupPeerConnection(SSyncPeer *pPeer) {
  int32_t connFd = taosOpenTcpClientSocket(pPeer->ip, pPeer->port, 0);
  if (connFd < 0) {
    sDebug("%s, failed to open tcp socket since %s", pPeer->id, strerror(errno));
-    taosTmrReset(syncCheckPeerConnection, tsSyncTimer * 1000, pPeer, tsSyncTmrCtrl, &pPeer->timer);
+    taosTmrReset(syncCheckPeerConnection, SYNC_CHECK_INTERVAL, pPeer, tsSyncTmrCtrl, &pPeer->timer);
    return;
  }

-  SFirstPkt firstPkt;
-  memset(&firstPkt, 0, sizeof(firstPkt));
-  firstPkt.syncHead.vgId = pPeer->nodeId ? pNode->vgId : 0;
-  firstPkt.syncHead.type = TAOS_SMSG_STATUS;
-  tstrncpy(firstPkt.fqdn, tsNodeFqdn, sizeof(firstPkt.fqdn));
-  firstPkt.port = tsSyncPort;
-  firstPkt.tranId = syncGenTranId();
-  firstPkt.sourceId = pNode->vgId;  // tell arbitrator its vgId
+  SSyncMsg msg;
+  syncBuildSyncSetupMsg(&msg, pPeer->nodeId ? pNode->vgId : 0);

-  if (taosWriteMsg(connFd, &firstPkt, sizeof(firstPkt)) == sizeof(firstPkt)) {
-    sDebug("%s, connection to peer server is setup, pfd:%d sfd:%d tranId:%u", pPeer->id, connFd, pPeer->syncFd, firstPkt.tranId);
+  if (taosWriteMsg(connFd, &msg, sizeof(SSyncMsg)) == sizeof(SSyncMsg)) {
+    sDebug("%s, connection to peer server is setup, pfd:%d sfd:%d tranId:%u", pPeer->id, connFd, pPeer->syncFd, msg.tranId);
    pPeer->peerFd = connFd;
    pPeer->role = TAOS_SYNC_ROLE_UNSYNCED;
-    pPeer->pConn = taosAllocateTcpConn(tsTcpPool, pPeer, connFd);
+    pPeer->pConn = syncAllocateTcpConn(tsTcpPool, pPeer, connFd);
    syncAddPeerRef(pPeer);
  } else {
    sDebug("%s, failed to setup peer connection to server since %s, try later", pPeer->id, strerror(errno));
    taosClose(connFd);
-    taosTmrReset(syncCheckPeerConnection, tsSyncTimer * 1000, pPeer, tsSyncTmrCtrl, &pPeer->timer);
+    taosTmrReset(syncCheckPeerConnection, SYNC_CHECK_INTERVAL, pPeer, tsSyncTmrCtrl, &pPeer->timer);
  }
 }

@ -1116,14 +1051,21 @@ static void syncProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {
  tinet_ntoa(ipstr, sourceIp);
  sDebug("peer TCP connection from ip:%s", ipstr);

-  SFirstPkt firstPkt;
-  if (taosReadMsg(connFd, &firstPkt, sizeof(firstPkt)) != sizeof(firstPkt)) {
-    sError("failed to read peer first pkt from ip:%s since %s", ipstr, strerror(errno));
+  SSyncMsg msg;
+  if (taosReadMsg(connFd, &msg, sizeof(SSyncMsg)) != sizeof(SSyncMsg)) {
+    sError("failed to read peer sync msg from ip:%s since %s", ipstr, strerror(errno));
    taosCloseSocket(connFd);
    return;
  }

-  int32_t     vgId = firstPkt.syncHead.vgId;
+  int32_t code = syncCheckHead((SSyncHead *)(&msg));
+  if (code != 0) {
+    sError("failed to check peer sync msg from ip:%s since %s", ipstr, strerror(code));
+    taosCloseSocket(connFd);
+    return;
+  }
+
+  int32_t     vgId = msg.head.vgId;
  SSyncNode **ppNode = taosHashGet(tsVgIdHash, &vgId, sizeof(int32_t));
  if (ppNode == NULL || *ppNode == NULL) {
    sError("vgId:%d, vgId could not be found", vgId);
@ -1131,7 +1073,7 @@ static void syncProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {
    return;
  }

-  sDebug("vgId:%d, firstPkt is received, tranId:%u", vgId, firstPkt.tranId);
+  sDebug("vgId:%d, sync msg is received, tranId:%u", vgId, msg.tranId);

  SSyncNode *pNode = *ppNode;
  pthread_mutex_lock(&pNode->mutex);
@ -1139,27 +1081,27 @@ static void syncProcessIncommingConnection(int32_t connFd, uint32_t sourceIp) {
  SSyncPeer *pPeer;
  for (i = 0; i < pNode->replica; ++i) {
    pPeer = pNode->peerInfo[i];
-    if (pPeer && (strcmp(pPeer->fqdn, firstPkt.fqdn) == 0) && (pPeer->port == firstPkt.port)) break;
+    if (pPeer && (strcmp(pPeer->fqdn, msg.fqdn) == 0) && (pPeer->port == msg.port)) break;
  }

  pPeer = (i < pNode->replica) ? pNode->peerInfo[i] : NULL;
  if (pPeer == NULL) {
-    sError("vgId:%d, peer:%s:%u not configured", pNode->vgId, firstPkt.fqdn, firstPkt.port);
+    sError("vgId:%d, peer:%s:%u not configured", pNode->vgId, msg.fqdn, msg.port);
    taosCloseSocket(connFd);
    // syncSendVpeerCfgMsg(sync);
  } else {
    // first packet tells what kind of link
-    if (firstPkt.syncHead.type == TAOS_SMSG_SYNC_DATA) {
+    if (msg.head.type == TAOS_SMSG_SYNC_DATA) {
      pPeer->syncFd = connFd;
      nodeSStatus = TAOS_SYNC_STATUS_START;
-      sInfo("%s, sync-data pkt from master is received, tranId:%u, set sstatus:%s", pPeer->id, firstPkt.tranId,
+      sInfo("%s, sync-data msg from master is received, tranId:%u, set sstatus:%s", pPeer->id, msg.tranId,
            syncStatus[nodeSStatus]);
      syncCreateRestoreDataThread(pPeer);
    } else {
      sDebug("%s, TCP connection is up, pfd:%d sfd:%d, old pfd:%d", pPeer->id, connFd, pPeer->syncFd, pPeer->peerFd);
      syncClosePeerConn(pPeer);
      pPeer->peerFd = connFd;
-      pPeer->pConn = taosAllocateTcpConn(tsTcpPool, pPeer, connFd);
+      pPeer->pConn = syncAllocateTcpConn(tsTcpPool, pPeer, connFd);
      syncAddPeerRef(pPeer);
      sDebug("%s, ready to exchange data", pPeer->id);
      syncSendPeersStatusMsgToPeer(pPeer, 1, SYNC_STATUS_EXCHANGE_DATA, syncGenTranId());
@ -1192,15 +1134,15 @@ static int32_t syncSaveFwdInfo(SSyncNode *pNode, uint64_t version, void *mhandle
  SSyncFwds *pSyncFwds = pNode->pSyncFwds;
  int64_t    time = taosGetTimestampMs();

-  if (pSyncFwds->fwds >= tsMaxFwdInfo) {
-    // pSyncFwds->first = (pSyncFwds->first + 1) % tsMaxFwdInfo;
+  if (pSyncFwds->fwds >= SYNC_MAX_FWDS) {
+    // pSyncFwds->first = (pSyncFwds->first + 1) % SYNC_MAX_FWDS;
    // pSyncFwds->fwds--;
    sError("vgId:%d, failed to save fwd info, hver:%" PRIu64 " fwds:%d", pNode->vgId, version, pSyncFwds->fwds);
    return TSDB_CODE_SYN_TOO_MANY_FWDINFO;
  }

  if (pSyncFwds->fwds > 0) {
-    pSyncFwds->last = (pSyncFwds->last + 1) % tsMaxFwdInfo;
+    pSyncFwds->last = (pSyncFwds->last + 1) % SYNC_MAX_FWDS;
  }

  SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + pSyncFwds->last;
@ -1223,7 +1165,7 @@ static void syncRemoveConfirmedFwdInfo(SSyncNode *pNode) {
    SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + pSyncFwds->first;
    if (pFwdInfo->confirmed == 0) break;

-    pSyncFwds->first = (pSyncFwds->first + 1) % tsMaxFwdInfo;
+    pSyncFwds->first = (pSyncFwds->first + 1) % SYNC_MAX_FWDS;
    pSyncFwds->fwds--;
    if (pSyncFwds->fwds == 0) pSyncFwds->first = pSyncFwds->last;
    sTrace("vgId:%d, fwd info is removed, hver:%" PRIu64 " fwds:%d", pNode->vgId, pFwdInfo->version, pSyncFwds->fwds);
@ -1248,7 +1190,7 @@ static void syncProcessFwdAck(SSyncNode *pNode, SFwdInfo *pFwdInfo, int32_t code
  }

  if (confirm && pFwdInfo->confirmed == 0) {
-    sTrace("vgId:%d, forward is confirmed, hver:%" PRIu64 " code:%x", pNode->vgId, pFwdInfo->version, pFwdInfo->code);
+    sTrace("vgId:%d, forward is confirmed, hver:%" PRIu64 " code:0x%x", pNode->vgId, pFwdInfo->version, pFwdInfo->code);
    (*pNode->confirmForward)(pNode->vgId, pFwdInfo->mhandle, pFwdInfo->code);
    pFwdInfo->confirmed = 1;
  }
@ -1289,7 +1231,7 @@ static void syncMonitorFwdInfos(void *param, void *tmrId) {
    if (pSyncFwds->fwds > 0) {
      pthread_mutex_lock(&pNode->mutex);
      for (int32_t i = 0; i < pSyncFwds->fwds; ++i) {
-        SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + (pSyncFwds->first + i) % tsMaxFwdInfo;
+        SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + (pSyncFwds->first + i) % SYNC_MAX_FWDS;
        if (ABS(time - pFwdInfo->time) < 2000) break;

        sDebug("vgId:%d, forward info expired, hver:%" PRIu64 " curtime:%" PRIu64 " savetime:%" PRIu64, pNode->vgId,
@ -1334,14 +1276,12 @@ static int32_t syncForwardToPeerImpl(SSyncNode *pNode, void *data, void *mhandle

  if (pNode->replica == 1 || nodeRole != TAOS_SYNC_ROLE_MASTER) return 0;

-  // only pkt from RPC or CQ can be forwarded
+  // only msg from RPC or CQ can be forwarded
  if (qtype != TAOS_QTYPE_RPC && qtype != TAOS_QTYPE_CQ) return 0;

    // a hacker way to improve the performance
  pSyncHead = (SSyncHead *)(((char *)pWalHead) - sizeof(SSyncHead));
-  pSyncHead->type = TAOS_SMSG_FORWARD;
-  pSyncHead->pversion = 0;
-  pSyncHead->len = sizeof(SWalHead) + pWalHead->len;
+  syncBuildSyncFwdMsg(pSyncHead, pNode->vgId, sizeof(SWalHead) + pWalHead->len);
  fwdLen = pSyncHead->len + sizeof(SSyncHead);  // include the WAL and SYNC head

  pthread_mutex_lock(&pNode->mutex);
@ -1371,4 +1311,3 @@ static int32_t syncForwardToPeerImpl(SSyncNode *pNode, void *data, void *mhandle

  return code;
 }
-
--- a/src/sync/src/syncMsg.c
+++ b/src/sync/src/syncMsg.c
@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "os.h"
+#include "taoserror.h"
+#include "tglobal.h"
+#include "tchecksum.h"
+#include "syncInt.h"
+
+char *statusType[] = {
+  "broadcast",
+  "broadcast-rsp",
+  "setup-conn",
+  "setup-conn-rsp",
+  "exchange-data",
+  "exchange-data-rsp",
+  "check-role",
+  "check-role-rsp"
+};
+
+uint16_t syncGenTranId() {
+  return taosRand() & 0XFFFF;
+}
+
+static void syncBuildHead(SSyncHead *pHead) {
+  pHead->protocol = SYNC_PROTOCOL_VERSION;
+  pHead->signature = SYNC_SIGNATURE;
+  pHead->code = 0;
+  pHead->cId = 0;
+  taosCalcChecksumAppend(0, (uint8_t *)pHead, sizeof(SSyncHead));
+}
+
+int32_t syncCheckHead(SSyncHead *pHead) {
+  if (pHead->protocol != SYNC_PROTOCOL_VERSION) return TSDB_CODE_SYN_MISMATCHED_PROTOCOL;
+  if (pHead->signature != SYNC_SIGNATURE) return TSDB_CODE_SYN_MISMATCHED_SIGNATURE;
+  if (pHead->cId != 0) return TSDB_CODE_SYN_MISMATCHED_CLUSTERID;
+  if (pHead->len <= 0 || pHead->len > TSDB_MAX_WAL_SIZE) return TSDB_CODE_SYN_INVALID_MSGLEN;
+  if (pHead->type <= TAOS_SMSG_START || pHead->type >= TAOS_SMSG_END) return TSDB_CODE_SYN_INVALID_MSGTYPE;
+  if (!taosCheckChecksumWhole((uint8_t *)pHead, sizeof(SSyncHead))) return TSDB_CODE_SYN_INVALID_CHECKSUM;
+
+  return TSDB_CODE_SUCCESS;
+}
+
+void syncBuildSyncFwdMsg(SSyncHead *pHead, int32_t vgId, int32_t len) {
+  pHead->type = TAOS_SMSG_SYNC_FWD;
+  pHead->vgId = vgId;
+  pHead->len = len;
+  syncBuildHead(pHead);
+}
+
+void syncBuildSyncFwdRsp(SFwdRsp *pMsg, int32_t vgId, uint64_t version, int32_t code) {
+  pMsg->head.type = TAOS_SMSG_SYNC_FWD_RSP;
+  pMsg->head.vgId = vgId;
+  pMsg->head.len = sizeof(SFwdRsp) - sizeof(SSyncHead);
+  syncBuildHead(&pMsg->head);
+
+  pMsg->version = version;
+  pMsg->code = code;
+}
+
+static void syncBuildMsg(SSyncMsg *pMsg, int32_t vgId, ESyncMsgType type) {
+  pMsg->head.type = type;
+  pMsg->head.vgId = vgId;
+  pMsg->head.len = sizeof(SSyncMsg) - sizeof(SSyncHead);
+  syncBuildHead(&pMsg->head);
+
+  pMsg->port = tsSyncPort;
+  pMsg->tranId = syncGenTranId();
+  pMsg->sourceId = vgId;
+  tstrncpy(pMsg->fqdn, tsNodeFqdn, TSDB_FQDN_LEN);
+}
+
+void syncBuildSyncReqMsg(SSyncMsg *pMsg, int32_t vgId) { syncBuildMsg(pMsg, vgId, TAOS_SMSG_SYNC_REQ); }
+void syncBuildSyncDataMsg(SSyncMsg *pMsg, int32_t vgId) { syncBuildMsg(pMsg, vgId, TAOS_SMSG_SYNC_DATA); }
+void syncBuildSyncSetupMsg(SSyncMsg *pMsg, int32_t vgId) { syncBuildMsg(pMsg, vgId, TAOS_SMSG_SETUP); }
+
+void syncBuildPeersStatus(SPeersStatus *pMsg, int32_t vgId) {
+  pMsg->head.type = TAOS_SMSG_STATUS;
+  pMsg->head.vgId = vgId;
+  pMsg->head.len = sizeof(SPeersStatus) - sizeof(SSyncHead);
+  syncBuildHead(&pMsg->head);
+}
+
+void syncBuildFileAck(SFileAck *pMsg, int32_t vgId) {
+  pMsg->head.type = TAOS_SMSG_SYNC_FILE_RSP;
+  pMsg->head.vgId = vgId;
+  pMsg->head.len = sizeof(SFileAck) - sizeof(SSyncHead);
+  syncBuildHead(&pMsg->head);
+}
+
+void syncBuildFileInfo(SFileInfo *pMsg, int32_t vgId) {
+  pMsg->head.type = TAOS_SMSG_SYNC_FILE;
+  pMsg->head.vgId = vgId;
+  pMsg->head.len = sizeof(SFileInfo) - sizeof(SSyncHead);
+  syncBuildHead(&pMsg->head);
+}
--- a/src/sync/src/syncRestore.c
+++ b/src/sync/src/syncRestore.c
@ -56,7 +56,7 @@ static int32_t syncRestoreFile(SSyncPeer *pPeer, uint64_t *fversion) {
  SSyncNode *pNode = pPeer->pSyncNode;
  SFileInfo  minfo; memset(&minfo, 0, sizeof(SFileInfo)); /* = {0}; */
  SFileInfo  sinfo; memset(&sinfo, 0, sizeof(SFileInfo)); /* = {0}; */
-  SFileAck   fileAck = {0};
+  SFileAck   fileAck; memset(&fileAck, 0, sizeof(SFileAck));
  int32_t    code = -1;
  char       name[TSDB_FILENAME_LEN * 2] = {0};
  uint32_t   pindex = 0;  // index in last restore
@ -73,6 +73,13 @@ static int32_t syncRestoreFile(SSyncPeer *pPeer, uint64_t *fversion) {
      break;
    }

+    assert(ret == sizeof(SFileInfo));
+    ret = syncCheckHead((SSyncHead *)(&minfo));
+    if (ret != 0) {
+      sError("%s, failed to check fileinfo while restore file since %s", pPeer->id, strerror(ret));
+      break;
+    }
+
    // if no more file from master, break;
    if (minfo.name[0] == 0 || minfo.magic == 0) {
      sDebug("%s, no more files to restore", pPeer->id);
@ -94,12 +101,13 @@ static int32_t syncRestoreFile(SSyncPeer *pPeer, uint64_t *fversion) {
                                        &sinfo.fversion);

    // if file not there or magic is not the same, file shall be synced
-    memset(&fileAck, 0, sizeof(fileAck));
+    memset(&fileAck, 0, sizeof(SFileAck));
+    syncBuildFileAck(&fileAck, pNode->vgId);
    fileAck.sync = (sinfo.magic != minfo.magic || sinfo.name[0] == 0) ? 1 : 0;

    // send file ack
-    ret = taosWriteMsg(pPeer->syncFd, &fileAck, sizeof(fileAck));
-    if (ret != sizeof(fileAck)) {
+    ret = taosWriteMsg(pPeer->syncFd, &fileAck, sizeof(SFileAck));
+    if (ret != sizeof(SFileAck)) {
      sError("%s, failed to write file:%s ack while restore file since %s", pPeer->id, minfo.name, strerror(errno));
      break;
    }
@ -289,12 +297,12 @@ static int32_t syncRestoreDataStepByStep(SSyncPeer *pPeer) {
  uint64_t fversion = 0;

  sInfo("%s, start to restore, sstatus:%s", pPeer->id, syncStatus[pPeer->sstatus]);
-  SFirstPktRsp firstPktRsp = {.sync = 1, .tranId = syncGenTranId()};
-  if (taosWriteMsg(pPeer->syncFd, &firstPktRsp, sizeof(SFirstPktRsp)) != sizeof(SFirstPktRsp)) {
-    sError("%s, failed to send sync firstPkt rsp since %s", pPeer->id, strerror(errno));
+  SSyncRsp rsp = {.sync = 1, .tranId = syncGenTranId()};
+  if (taosWriteMsg(pPeer->syncFd, &rsp, sizeof(SSyncRsp)) != sizeof(SSyncRsp)) {
+    sError("%s, failed to send sync rsp since %s", pPeer->id, strerror(errno));
    return -1;
  }
-  sDebug("%s, send firstPktRsp to peer, tranId:%u", pPeer->id, firstPktRsp.tranId);
+  sDebug("%s, send sync rsp to peer, tranId:%u", pPeer->id, rsp.tranId);

  sInfo("%s, start to restore file, set sstatus:%s", pPeer->id, syncStatus[nodeSStatus]);
  int32_t code = syncRestoreFile(pPeer, &fversion);
--- a/src/sync/src/syncRetrieve.c
+++ b/src/sync/src/syncRetrieve.c
@ -88,7 +88,7 @@ static bool syncAreFilesModified(SSyncNode *pNode, SSyncPeer *pPeer) {
 static int32_t syncRetrieveFile(SSyncPeer *pPeer) {
  SSyncNode *pNode = pPeer->pSyncNode;
  SFileInfo  fileInfo; memset(&fileInfo, 0, sizeof(SFileInfo));
-  SFileAck   fileAck = {0};
+  SFileAck   fileAck; memset(&fileAck, 0, sizeof(SFileAck));
  int32_t    code = -1;
  char       name[TSDB_FILENAME_LEN * 2] = {0};

@ -103,11 +103,12 @@ static int32_t syncRetrieveFile(SSyncPeer *pPeer) {
    fileInfo.size = 0;
    fileInfo.magic = (*pNode->getFileInfo)(pNode->vgId, fileInfo.name, &fileInfo.index, TAOS_SYNC_MAX_INDEX,
                                           &fileInfo.size, &fileInfo.fversion);
+    syncBuildFileInfo(&fileInfo, pNode->vgId);
    sDebug("%s, file:%s info is sent, size:%" PRId64, pPeer->id, fileInfo.name, fileInfo.size);

    // send the file info
-    int32_t ret = taosWriteMsg(pPeer->syncFd, &(fileInfo), sizeof(fileInfo));
-    if (ret != sizeof(fileInfo)) {
+    int32_t ret = taosWriteMsg(pPeer->syncFd, &(fileInfo), sizeof(SFileInfo));
+    if (ret != sizeof(SFileInfo)) {
      code = -1;
      sError("%s, failed to write file:%s info while retrieve file since %s", pPeer->id, fileInfo.name, strerror(errno));
      break;
@ -128,6 +129,13 @@ static int32_t syncRetrieveFile(SSyncPeer *pPeer) {
      break;
    }

+    ret = syncCheckHead((SSyncHead*)(&fileAck));
+    if (ret != 0) {
+      code = -1;
+      sError("%s, failed to check file:%s ack while retrieve file since %s", pPeer->id, fileInfo.name, strerror(ret));
+      break;
+    }
+
    // set the peer sync version
    pPeer->sversion = fileInfo.fversion;

@ -405,27 +413,22 @@ static int32_t syncRetrieveWal(SSyncPeer *pPeer) {
 static int32_t syncRetrieveFirstPkt(SSyncPeer *pPeer) {
  SSyncNode *pNode = pPeer->pSyncNode;

-  SFirstPkt firstPkt;
-  memset(&firstPkt, 0, sizeof(firstPkt));
-  firstPkt.syncHead.type = TAOS_SMSG_SYNC_DATA;
-  firstPkt.syncHead.vgId = pNode->vgId;
-  firstPkt.tranId = syncGenTranId();
-  tstrncpy(firstPkt.fqdn, tsNodeFqdn, sizeof(firstPkt.fqdn));
-  firstPkt.port = tsSyncPort;
+  SSyncMsg msg;
+  syncBuildSyncDataMsg(&msg, pNode->vgId);

-  if (taosWriteMsg(pPeer->syncFd, &firstPkt, sizeof(firstPkt)) != sizeof(firstPkt)) {
-    sError("%s, failed to send sync firstPkt since %s, tranId:%u", pPeer->id, strerror(errno), firstPkt.tranId);
+  if (taosWriteMsg(pPeer->syncFd, &msg, sizeof(SSyncMsg)) != sizeof(SSyncMsg)) {
+    sError("%s, failed to send sync-data msg since %s, tranId:%u", pPeer->id, strerror(errno), msg.tranId);
    return -1;
  }
-  sDebug("%s, send sync-data pkt to peer, tranId:%u", pPeer->id, firstPkt.tranId);
+  sDebug("%s, send sync-data msg to peer, tranId:%u", pPeer->id, msg.tranId);

-  SFirstPktRsp firstPktRsp;
-  if (taosReadMsg(pPeer->syncFd, &firstPktRsp, sizeof(SFirstPktRsp)) != sizeof(SFirstPktRsp)) {
-    sError("%s, failed to read sync firstPkt rsp since %s, tranId:%u", pPeer->id, strerror(errno), firstPkt.tranId);
+  SSyncRsp rsp;
+  if (taosReadMsg(pPeer->syncFd, &rsp, sizeof(SSyncRsp)) != sizeof(SSyncRsp)) {
+    sError("%s, failed to read sync-data rsp since %s, tranId:%u", pPeer->id, strerror(errno), msg.tranId);
    return -1;
  }

-  sDebug("%s, recv firstPktRsp from peer, tranId:%u", pPeer->id, firstPkt.tranId);
+  sDebug("%s, recv sync-data rsp from peer, tranId:%u rsp-tranId:%u", pPeer->id, msg.tranId, rsp.tranId);
  return 0;
 }

--- a/src/sync/src/taosTcpPool.c
+++ b/src/sync/src/taosTcpPool.c
@ -19,10 +19,10 @@
 #include "tutil.h"
 #include "tsocket.h"
 #include "taoserror.h"
-#include "taosTcpPool.h"
 #include "twal.h"
 #include "tsync.h"
 #include "syncInt.h"
+#include "syncTcp.h"

 typedef struct SThreadObj {
  pthread_t thread;
@ -47,12 +47,12 @@ typedef struct {
  int32_t     closedByApp;
 } SConnObj;

-static void *taosAcceptPeerTcpConnection(void *argv);
-static void *taosProcessTcpData(void *param);
-static void  taosStopPoolThread(SThreadObj *pThread);
-static SThreadObj *taosGetTcpThread(SPoolObj *pPool);
+static void *syncAcceptPeerTcpConnection(void *argv);
+static void *syncProcessTcpData(void *param);
+static void  syncStopPoolThread(SThreadObj *pThread);
+static SThreadObj *syncGetTcpThread(SPoolObj *pPool);

-void *taosOpenTcpThreadPool(SPoolInfo *pInfo) {
+void *syncOpenTcpThreadPool(SPoolInfo *pInfo) {
  pthread_attr_t thattr;

  SPoolObj *pPool = calloc(sizeof(SPoolObj), 1);
@ -80,7 +80,7 @@ void *taosOpenTcpThreadPool(SPoolInfo *pInfo) {

  pthread_attr_init(&thattr);
  pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_JOINABLE);
-  if (pthread_create(&(pPool->thread), &thattr, (void *)taosAcceptPeerTcpConnection, pPool) != 0) {
+  if (pthread_create(&(pPool->thread), &thattr, (void *)syncAcceptPeerTcpConnection, pPool) != 0) {
    sError("failed to create accept thread for TCP server since %s", strerror(errno));
    close(pPool->acceptFd);
    tfree(pPool->pThread);
@ -94,7 +94,7 @@ void *taosOpenTcpThreadPool(SPoolInfo *pInfo) {
  return pPool;
 }

-void taosCloseTcpThreadPool(void *param) {
+void syncCloseTcpThreadPool(void *param) {
  SPoolObj *  pPool = param;
  SThreadObj *pThread;

@ -103,7 +103,7 @@ void taosCloseTcpThreadPool(void *param) {

  for (int32_t i = 0; i < pPool->info.numOfThreads; ++i) {
    pThread = pPool->pThread[i];
-    if (pThread) taosStopPoolThread(pThread);
+    if (pThread) syncStopPoolThread(pThread);
  }

  sDebug("%p TCP pool is closed", pPool);
@ -112,7 +112,7 @@ void taosCloseTcpThreadPool(void *param) {
  tfree(pPool);
 }

-void *taosAllocateTcpConn(void *param, void *pPeer, int32_t connFd) {
+void *syncAllocateTcpConn(void *param, void *pPeer, int32_t connFd) {
  struct epoll_event event;
  SPoolObj *pPool = param;

@ -122,7 +122,7 @@ void *taosAllocateTcpConn(void *param, void *pPeer, int32_t connFd) {
    return NULL;
  }

-  SThreadObj *pThread = taosGetTcpThread(pPool);
+  SThreadObj *pThread = syncGetTcpThread(pPool);
  if (pThread == NULL) {
    tfree(pConn);
    return NULL;
@ -149,7 +149,7 @@ void *taosAllocateTcpConn(void *param, void *pPeer, int32_t connFd) {
  return pConn;
 }

-void taosFreeTcpConn(void *param) {
+void syncFreeTcpConn(void *param) {
  SConnObj *  pConn = param;
  SThreadObj *pThread = pConn->pThread;

@ -175,7 +175,7 @@ static void taosProcessBrokenLink(SConnObj *pConn) {

 #define maxEvents 10

-static void *taosProcessTcpData(void *param) {
+static void *syncProcessTcpData(void *param) {
  SThreadObj *pThread = (SThreadObj *)param;
  SPoolObj *  pPool = pThread->pPool;
  SPoolInfo * pInfo = &pPool->info;
@ -222,7 +222,7 @@ static void *taosProcessTcpData(void *param) {

      if (pConn->closedByApp == 0) {
        if ((*pInfo->processIncomingMsg)(pConn->ahandle, buffer) < 0) {
-          taosFreeTcpConn(pConn);
+          syncFreeTcpConn(pConn);
          continue;
        }
      }
@ -239,7 +239,7 @@ static void *taosProcessTcpData(void *param) {
  return NULL;
 }

-static void *taosAcceptPeerTcpConnection(void *argv) {
+static void *syncAcceptPeerTcpConnection(void *argv) {
  SPoolObj * pPool = (SPoolObj *)argv;
  SPoolInfo *pInfo = &pPool->info;

@ -268,7 +268,7 @@ static void *taosAcceptPeerTcpConnection(void *argv) {
  return NULL;
 }

-static SThreadObj *taosGetTcpThread(SPoolObj *pPool) {
+static SThreadObj *syncGetTcpThread(SPoolObj *pPool) {
  SThreadObj *pThread = pPool->pThread[pPool->nextId];

  if (pThread) return pThread;
@ -286,7 +286,7 @@ static SThreadObj *taosGetTcpThread(SPoolObj *pPool) {
  pthread_attr_t thattr;
  pthread_attr_init(&thattr);
  pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_JOINABLE);
-  int32_t ret = pthread_create(&(pThread->thread), &thattr, (void *)taosProcessTcpData, pThread);
+  int32_t ret = pthread_create(&(pThread->thread), &thattr, (void *)syncProcessTcpData, pThread);
  pthread_attr_destroy(&thattr);

  if (ret != 0) {
@ -303,7 +303,7 @@ static SThreadObj *taosGetTcpThread(SPoolObj *pPool) {
  return pThread;
 }

-static void taosStopPoolThread(SThreadObj *pThread) {
+static void syncStopPoolThread(SThreadObj *pThread) {
  pthread_t thread = pThread->thread;
  if (!taosCheckPthreadValid(thread)) {
    return;
--- a/src/sync/test/syncServer.c
+++ b/src/sync/test/syncServer.c
@ -100,7 +100,7 @@ int processRpcMsg(void *item) {
    pHead->msgType = pMsg->msgType;
    pHead->len = pMsg->contLen;

-    uDebug("ver:%" PRIu64 ", pkt from client processed", pHead->version);
+    uDebug("ver:%" PRIu64 ", rsp from client processed", pHead->version);
    writeIntoWal(pHead);
    syncForwardToPeer(syncHandle, pHead, item, TAOS_QTYPE_RPC);

@ -275,7 +275,7 @@ int getWalInfo(int32_t vgId, char *name, int64_t *index) {
 int writeToCache(int32_t vgId, void *data, int type) {
  SWalHead *pHead = data;

-  uDebug("pkt from peer is received, ver:%" PRIu64 " len:%d type:%d", pHead->version, pHead->len, type);
+  uDebug("rsp from peer is received, ver:%" PRIu64 " len:%d type:%d", pHead->version, pHead->len, type);

  int   msgSize = pHead->len + sizeof(SWalHead);
  void *pMsg = taosAllocateQitem(msgSize);
--- a/src/wal/src/walWrite.c
+++ b/src/wal/src/walWrite.c
@ -297,16 +297,14 @@ static int32_t walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp, ch
      }
    }

-    if (pHead->len > size - sizeof(SWalHead)) {
-      size = sizeof(SWalHead) + pHead->len;
-      buffer = realloc(buffer, size);
-      if (buffer == NULL) {
-        wError("vgId:%d, file:%s, failed to open for restore since %s", pWal->vgId, name, strerror(errno));
-        code = TAOS_SYSTEM_ERROR(errno);
+    if (pHead->len < 0 || pHead->len > size - sizeof(SWalHead)) {
+      wError("vgId:%d, file:%s, wal head len out of range, hver:%" PRIu64 " len:%d offset:%" PRId64, pWal->vgId, name,
+             pHead->version, pHead->len, offset);
+      code = walSkipCorruptedRecord(pWal, pHead, tfd, &offset);
+      if (code != TSDB_CODE_SUCCESS) {
+        walFtruncate(pWal, tfd, offset);
        break;
      }
-
-      pHead = buffer;
    }

    ret = tfRead(tfd, pHead->cont, pHead->len);
--- a/src/wal/test/waltest.c
+++ b/src/wal/test/waltest.c
@ -76,7 +76,7 @@ int main(int argc, char *argv[]) {

  taosInitLog("wal.log", 100000, 10);

-  SWalCfg walCfg;
+  SWalCfg walCfg = {0};
  walCfg.walLevel = level;
  walCfg.keep = keep;

--- a/tests/pytest/query/queryError.py
+++ b/tests/pytest/query/queryError.py
@ -56,6 +56,15 @@ class TDTestCase:
        # query .. order by non-time field
        tdSql.error("select * from st order by name")

+        # TD-2133
+        tdSql.error("select diff(tagtype),bottom(tagtype,1) from dev_001")
+
+        # TD-2190
+        tdSql.error("select min(tagtype),max(tagtype) from dev_002 interval(1n) fill(prev)")
+
+        # TD-2208
+        tdSql.error("select diff(tagtype),top(tagtype,1) from dev_001")
+
    def stop(self):
        tdSql.close()
        tdLog.success("%s successfully executed" % __file__)
--- a/tests/pytest/test.py
+++ b/tests/pytest/test.py
@ -115,9 +115,21 @@ if __name__ == "__main__":
    tdDnodes.init(deployPath)
    tdDnodes.setTestCluster(testCluster)
    tdDnodes.setValgrind(valgrind)
-
    tdDnodes.stopAll()
-    tdDnodes.deploy(1)
+    is_test_framework = 0
+    key_word = 'tdCases.addLinux'
+    if key_word in open(fileName).read():
+        is_test_framework = 1
+    if is_test_framework:
+        moduleName = fileName.replace(".py", "").replace("/", ".")
+        uModule = importlib.import_module(moduleName)
+        try:
+            ucase = uModule.TDTestCase()
+            tdDnodes.deploy(1,ucase.updatecfgDict)
+        except :
+            tdDnodes.deploy(1,{})
+    else:
+        tdDnodes.deploy(1,{})
    tdDnodes.start(1)

    if masterIp == "":
--- a/tests/pytest/util/dnodes.py
+++ b/tests/pytest/util/dnodes.py
@ -108,6 +108,36 @@ class TDDnode:
        self.deployed = 0
        self.testCluster = False
        self.valgrind = 0
+        self.cfgDict = {
+            "numOfLogLines":"100000000",
+            "mnodeEqualVnodeNum":"0",
+            "walLevel":"2",
+            "fsync":"1000",
+            "statusInterval":"1",
+            "numOfMnodes":"3",
+            "numOfThreadsPerCore":"2.0",
+            "monitor":"0",
+            "maxVnodeConnections":"30000",
+            "maxMgmtConnections":"30000",
+            "maxMeterConnections":"30000",
+            "maxShellConns":"30000",
+            "locale":"en_US.UTF-8",
+            "charset":"UTF-8",
+            "asyncLog":"0",
+            "anyIp":"0",
+            "tsEnableTelemetryReporting":"0",
+            "dDebugFlag":"135",
+            "mDebugFlag":"135",
+            "sdbDebugFlag":"135",
+            "rpcDebugFlag":"135",
+            "tmrDebugFlag":"131",
+            "cDebugFlag":"135",
+            "httpDebugFlag":"135",
+            "monitorDebugFlag":"135",
+            "udebugFlag":"135",
+            "jnidebugFlag":"135",
+            "qdebugFlag":"135"
+        }

    def init(self, path):
        self.path = path
@ -131,7 +161,10 @@ class TDDnode:

        return totalSize

-    def deploy(self):
+    def addExtraCfg(self, option, value):
+        self.cfgDict.update({option: value})
+
+    def deploy(self, *updatecfgDict):
        self.logDir = "%s/sim/dnode%d/log" % (self.path, self.index)
        self.dataDir = "%s/sim/dnode%d/data" % (self.path, self.index)
        self.cfgDir = "%s/sim/dnode%d/cfg" % (self.path, self.index)
@ -175,36 +208,17 @@ class TDDnode:
            self.cfg("publicIp", "192.168.0.%d" % (self.index))
            self.cfg("internalIp", "192.168.0.%d" % (self.index))
            self.cfg("privateIp", "192.168.0.%d" % (self.index))
+        
        self.cfg("dataDir",self.dataDir)
        self.cfg("logDir",self.logDir)
-        self.cfg("numOfLogLines", "100000000")
-        self.cfg("mnodeEqualVnodeNum", "0")
-        self.cfg("walLevel", "2")
-        self.cfg("fsync", "1000")
-        self.cfg("statusInterval", "1")
-        self.cfg("numOfMnodes", "3")
-        self.cfg("numOfThreadsPerCore", "2.0")
-        self.cfg("monitor", "0")
-        self.cfg("maxVnodeConnections", "30000")
-        self.cfg("maxMgmtConnections", "30000")
-        self.cfg("maxMeterConnections", "30000")
-        self.cfg("maxShellConns", "30000")
-        self.cfg("locale", "en_US.UTF-8")
-        self.cfg("charset", "UTF-8")
-        self.cfg("asyncLog", "0")
-        self.cfg("anyIp", "0")
-        self.cfg("tsEnableTelemetryReporting", "0")
-        self.cfg("dDebugFlag", "135")
-        self.cfg("mDebugFlag", "135")
-        self.cfg("sdbDebugFlag", "135")
-        self.cfg("rpcDebugFlag", "135")
-        self.cfg("tmrDebugFlag", "131")
-        self.cfg("cDebugFlag", "135")
-        self.cfg("httpDebugFlag", "135")
-        self.cfg("monitorDebugFlag", "135")
-        self.cfg("udebugFlag", "135")
-        self.cfg("jnidebugFlag", "135")
-        self.cfg("qdebugFlag", "135")
+        print(updatecfgDict)
+        if updatecfgDict[0] and updatecfgDict[0][0]:
+            print(updatecfgDict[0][0])
+            for key,value in updatecfgDict[0][0].items():
+                self.addExtraCfg(key,value)
+        for key, value in self.cfgDict.items():
+            self.cfg(key, value)
+
        self.deployed = 1
        tdLog.debug(
            "dnode:%d is deployed and configured by %s" %
@ -260,6 +274,12 @@ class TDDnode:
            key = 'from offline to online'
            bkey = bytes(key,encoding="utf8")
            logFile = self.logDir + "/taosdlog.0"
+            i = 0
+            while not os.path.exists(logFile):
+                sleep(0.1)
+                i += 1
+                if i>50:
+                    break
            popen = subprocess.Popen('tail -f ' + logFile, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
            pid = popen.pid
            print('Popen.pid:' + str(pid))
@ -274,6 +294,7 @@ class TDDnode:
            tdLog.debug("wait 5 seconds for the dnode:%d to start." % (self.index))
            time.sleep(5)

+        
        # time.sleep(5)
    
    def startWithoutSleep(self):
@ -454,7 +475,7 @@ class TDDnodes:
    def setValgrind(self, value):
        self.valgrind = value

-    def deploy(self, index):
+    def deploy(self, index, *updatecfgDict):
        self.sim.setTestCluster(self.testCluster)

        if (self.simDeployed == False):
@ -464,7 +485,7 @@ class TDDnodes:
        self.check(index)
        self.dnodes[index - 1].setTestCluster(self.testCluster)
        self.dnodes[index - 1].setValgrind(self.valgrind)
-        self.dnodes[index - 1].deploy()
+        self.dnodes[index - 1].deploy(updatecfgDict)

    def cfg(self, index, option, value):
        self.check(index)
--- a/tests/script/jenkins/basic.txt
+++ b/tests/script/jenkins/basic.txt
@ -154,6 +154,7 @@ cd ../../../debug; make
 ./test.sh -f general/parser/repeatAlter.sim
 ./test.sh -f general/parser/union.sim
 ./test.sh -f general/parser/topbot.sim
+./test.sh -f general/parser/function.sim

 ./test.sh -f general/stable/disk.sim
 ./test.sh -f general/stable/dnode3.sim
--- a/tests/script/unique/db/replica_add13.sim
+++ b/tests/script/unique/db/replica_add13.sim
@ -110,6 +110,7 @@ sql insert into d1.t1 values(1589529000012, 2)
 sql insert into d2.t2 values(1589529000022, 2)
 sql insert into d3.t3 values(1589529000032, 2)
 sql insert into d4.t4 values(1589529000042, 2)
+sleep 1000

 sql select * from d1.t1
 if $rows != 2 then
@ -141,6 +142,7 @@ sql insert into d1.t1 values(1589529000013, 3)
 sql insert into d2.t2 values(1589529000023, 3)
 sql insert into d3.t3 values(1589529000033, 3)
 sql insert into d4.t4 values(1589529000043, 3)
+sleep 1000

 sql select * from d1.t1
 if $rows != 3 then
@ -172,6 +174,7 @@ sql insert into d1.t1 values(1589529000014, 4)
 sql insert into d2.t2 values(1589529000024, 4)
 sql insert into d3.t3 values(1589529000034, 4)
 sql insert into d4.t4 values(1589529000044, 4)
+sleep 1000

 sql select * from d1.t1
 print select * from d1.t1 $rows
@ -207,6 +210,7 @@ sql insert into d1.t1 values(1589529000015, 5)
 sql insert into d2.t2 values(1589529000025, 5)
 sql insert into d3.t3 values(1589529000035, 5)
 sql insert into d4.t4 values(1589529000045, 5)
+sleep 1000

 sql select * from d1.t1
 if $rows != 5 then
@ -238,6 +242,7 @@ sql insert into d1.t1 values(1589529000016, 6)
 sql insert into d2.t2 values(1589529000026, 6)
 sql insert into d3.t3 values(1589529000036, 6)
 sql insert into d4.t4 values(1589529000046, 6)
+sleep 1000

 sql select * from d1.t1
 if $rows != 6 then
--- a/tests/script/unique/db/replica_add23.sim
+++ b/tests/script/unique/db/replica_add23.sim
@ -110,6 +110,7 @@ sql insert into d1.t1 values(1588262400002, 2)
 sql insert into d2.t2 values(1588262400002, 2)
 sql insert into d3.t3 values(1588262400002, 2)
 sql insert into d4.t4 values(1588262400002, 2)
+sleep 1000

 sql select * from d1.t1
 if $rows != 2 then
@ -142,6 +143,7 @@ sql insert into d1.t1 values(1588262400003, 3)
 sql insert into d2.t2 values(1588262400003, 3)
 sql insert into d3.t3 values(1588262400003, 3)
 sql insert into d4.t4 values(1588262400003, 3)
+sleep 1000

 sql select * from d1.t1
 if $rows != 3 then
@ -173,6 +175,7 @@ sql insert into d1.t1 values(1588262400004, 4)
 sql insert into d2.t2 values(1588262400004, 4)
 sql insert into d3.t3 values(1588262400004, 4)
 sql insert into d4.t4 values(1588262400004, 4)
+sleep 1000

 sql select * from d1.t1
 if $rows != 4 then
@ -204,6 +207,7 @@ sql insert into d1.t1 values(1588262400005, 5)
 sql insert into d2.t2 values(1588262400005, 5)
 sql insert into d3.t3 values(1588262400005, 5)
 sql insert into d4.t4 values(1588262400005, 5)
+sleep 1000

 sql select * from d1.t1
 if $rows != 5 then
@ -235,6 +239,7 @@ sql insert into d1.t1 values(1588262400006, 6)
 sql insert into d2.t2 values(1588262400006, 6)
 sql insert into d3.t3 values(1588262400006, 6)
 sql insert into d4.t4 values(1588262400006, 6)
+sleep 1000

 sql select * from d1.t1
 if $rows != 6 then