canal nodejs

Canal Nodejs

This application is the node js version of Canal client.

It allows you to incrementally subscribe & consume data in MySQL database in a node js environment. For more information, please see the Canal wiki

Usage

 // 创建 simple canal connector 对象
let connector : CanalConnector = CanalConnectors . newSingleConnector ( {
   host : '127.0.0.1' ,
   port : 11111 ,
   destination : 'example' ,
   username : '' ,
   password : '' ,
   filter : '.*..*'
} ) ;

try {
   // 等待建立连接
   await connector . connect ( ) ;

   while ( true ) {
      // 拉取增量消息
      let message : Message = await connector . getWithoutAck ( 1 ) ;
      let batchId : number = message . id ;

      // 如果 batchId 或者变更条目为空，则代表未新增消息
      if ( batchId != - 1 && message . entries ?. length ) {
            try {
               // 打印变更消息或做其他业务操作
               printEntry ( message . entries ) ;
            } finally {
               // 当消费完毕，发送确认 ack
               await connector . ack ( batchId ) ;
            }
      }

      await sleep ( 3_000 ) ;
   }
} catch ( e : any ) {
   // 捕获出现的异常：
   // 1，连接建立时的异常
   // 2，拉取消息时的异常
   // 3，其他 socket 操作异常
   console . error ( 'Occur error' , e as Error ) ;
} finally {
   // 关闭连接
   connector . isConnect ( ) && connector . disconnect ( ) ;
}

For more information, please refer to the exmpale.ts file

Quick Start

1. Start canal-server

    # 创建 docker 网络
   docker network create canalsharp
   # 启动 docker 容器
   cd ./docker
   docker-compose up

2. Start the example file

    # 下载项目依赖
   npm install
   # 启动 example 文件
   npm run example

3. Added mysql DML

    # 查看 docker 容器
   docker ps
   # CONTAINER ID   IMAGE                       COMMAND                  CREATED        STATUS        PORTS                                                      NAMES
   # c52d627d987a   canal/canal-server:v1.1.5   "/alidata/bin/main.s…"   12 hours ago   Up 12 hours   9100/tcp, 11110/tcp, 11112/tcp, 0.0.0.0:11111->11111/tcp   canal-server
   # c9261bcf2fc7   mysql:8.0-oracle            "docker-entrypoint.s…"   12 hours ago   Up 12 hours   0.0.0.0:3306->3306/tcp, 33060/tcp                          mysql-8.0
   
   # 进入 mysql 容器
   docker exec -it c9261bcf2fc7 bash
   # 登录 mysql
   mysql -u root -p 123456
   # 选择数据库
   use test ;
   #  新增 DML 语句
   insert into user values(null, ' canal ' ) ;

4. Observe console output

    Insert: 
   [1] id : 8 <updated>
   [1] name : canal4 <updated>
   

contribute & feedback

If you find any problem or have something to add, you are welcome to submit a Pull Request to Issue

LICENSE

This project adopts Apache-2 license