1. 简介
Canal是阿里巴巴旗下的一款开源项目，纯Java开发。基于数据库增量日志解析，提供增量数据订阅&消费功能。
工作原理
Mysql主备复制原理
- MySQL master 将数据变更写入二进制日志( binary log, 其中记录叫做二进制日志事件binary log events，可以通过 show binlog events 进行查看)
- MySQL slave 将 master 的 binary log events 拷贝到它的中继日志(relay log)
- MySQL slave 重放 relay log 中事件，将数据变更反映它自己的数据
canal工作原理
- canal 模拟 MySQL slave 的交互协议，伪装自己为 MySQL slave ，向 MySQL master 发送 dump 协议
- MySQL master 收到 dump 请求，开始推送 binary log 给 slave (即 canal )
- canal 解析 binary log 对象(原始为 byte 流)
mysql的binlog
它记录了所有的DDL和DML(除了数据查询语句)语句，以事件形式记录，还包含语句所执行的消耗的时间。主要用来备份和数据同步。 binlog有三种模式：STATEMENT、ROW、MIXED
- STATEMENT 记录的是执行的sql语句
- ROW 记录的是真实的行数据记录
- MIXED 记录的是1+2，优先按照1的模式记录
比如：
update user set age = 33 对应STATEMENT模式只是记录了当前执行的sql，而对应ROW模式则有可能有成千上万条记录（当然这取决于你user表的记录数）
2. 可以干什么
基于日志增量订阅和消费的业务包括
- 数据库镜像
- 数据库实时备份
- 索引构建和实时维护(拆分异构索引、倒排索引等)
- 业务 cache 刷新
- 带业务逻辑的增量数据处理
当前的 canal 支持源端 MySQL 版本包括 5.1.x , 5.5.x , 5.6.x , 5.7.x , 8.0.x
3. 安装
原生安装请参考：https://github.com/alibaba/canal/wiki/QuickStart
3.1 docker-compose安装
3.1.1 创建同步用户
如果想查看mysql server的相关配置可以参考 https://www.cnblogs.com/ludangxin/p/16358928.html 中的master配置
CREATE USER canal IDENTIFIED BY 'canal'; GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%'; -- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ; FLUSH PRIVILEGES; 3.1.2 修改配置文件
首先启动一个零时的容器用于 将容器中的配置文件信息copy到宿主机
# run 零时容器 docker run --name canal-temp -d --rm canal/canal-server:v1.1.6 # 执行copy操作 copy配置文件到当前目录中 docker cp canal-temp:/home/admin/canal-server/conf ./canal-server/conf canal-server/conf配置文件目录结构如下
canal-server/conf ├── canal.properties # canal server 的配置文件参数信息 例如：服务的端口/集群参数/server 模式（# tcp, kafka, rocketMQ, rabbitMQ, pulsarMQ）等 ├── canal_local.properties ├── example # canal 实例相关配置信息，如果想要监听多个mysql server 可以copy此文件进行配置，当然也要在canal.properties的 canal.destinations 中添加对应的文件夹名称 │ ├── h2.mv.db │ ├── instance.properties │ └── meta.dat ├── logback.xml ... 修改配置文件信息
canal.properties我们使用默认的配置信息 即：canal.serverMode = tcp
example/instance.properties中配置mysql server连接信息 如下：
# position info # mysql url 我这里直接使用的是 mysql容器name canal.instance.master.address=my_mysql:3306 # 监听的binlog 文件名称 例：mysql-bin.000007 canal.instance.master.journal.name= # 日志文件的Offset canal.instance.master.position= # username/password canal.instance.dbUsername=canal canal.instance.dbPassword=canal canal.instance.connectionCharset = UTF-8 # table regex # 默认配置是同步所有的库和表 #canal.instance.filter.regex=.*\..* # 配置只监听test库的user表，如果需要读取多个表可以使用正则表达式或者用逗号隔开 canal.instance.filter.regex=test.user mysql 数据解析关注的表，Perl正则表达式.
多个正则之间以逗号(,)分隔，转义符需要双斜杠()
常见例子：
所有表：.* or .…
canal schema下所有表： canal…*
canal下的以canal打头的表：canal.canal.*
canal schema下的一张表：canal.test1
多个规则组合使用：canal…*,mysql.test1,mysql.test2 (逗号分隔)
注意：此过滤条件只针对row模式的数据有效(ps. mixed/statement因为不解
析sql，所以无法准确提取tableName进行过滤)
3.1.3 启动canal
docker-compose.yaml 如下
因为canal需要读取mysql server的bin-log所以需要设置加入到mysql server的网络中去
version: '3' services: canal: image: canal/canal-server:v1.1.6 hostname: canal container_name: canal restart: "no" ports: - "11111:11111" volumes: - "./canal-server/conf:/home/admin/canal-server/conf" - "./canal-server/logs:/home/admin/canal-server/logs" networks: - mysql_mysql networks: mysql_mysql: external: true 4. springboot 测试
4.1 添加依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <!-- https://mvnrepository.com/artifact/top.javatool/canal-spring-boot-starter --> <dependency> <groupId>top.javatool</groupId> <artifactId>canal-spring-boot-starter</artifactId> <version>1.2.1-RELEASE</version> </dependency> 4.2 添加配置
canal: server: localhost:11111 destination: example logging: level: top.javatool.canal.client.client: OFF 4.3 监听canal数据
package com.ldx.canaldemo.handler; import com.ldx.canaldemo.domain.User; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Component; import top.javatool.canal.client.annotation.CanalTable; import top.javatool.canal.client.handler.EntryHandler; @Slf4j @Component // 监听user表 @CanalTable(value = "user") public class UserHandler implements EntryHandler<User> { @Override public void insert(User user) { log.info("insert info {}", user); } @Override public void update(User before, User after) { log.info("update before {} ", before); log.info("update after {}", after); } @Override public void delete(User user) { log.info("delete {}", user); } } package com.ldx.canaldemo.domain; import lombok.Data; import javax.persistence.Column; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; import java.io.Serializable; @Data @Table(name = "user") public class User implements Serializable { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id") private Integer id; @Column(name = "username") private String username; @Column(name = "password") private String password; @Column(name = "sex") private Integer sex; } 4.4 测试
user表信息如下
CREATE TABLE `user` ( `id` int(11) NOT NULL, `username` varchar(255) COLLATE utf8mb4_bin DEFAULT NULL, `password` varchar(255) COLLATE utf8mb4_bin DEFAULT NULL, `age` int(1) DEFAULT NULL, `sex` int(1) COLLATE utf8mb4_bin DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin; 测试新增
INSERT INTO `test`.`user`(`id`, `username`, `password`, `age`, `sex`) VALUES (5, 'zhangtieniu', '123456', 28, 1); 查看控制台输出如下
2022-06-14 13:50:38.144 INFO 71053 --- [xecute-thread-1] com.ldx.canaldemo.handler.UserHandler : insert info User(id=5, username=zhangtieniu, password=123456, age=28, sex=1) 测试修改
UPDATE `test`.`user` SET `username` = 'zhangsan', age = 23 WHERE id = 5; 查看控制台输出如下
2022-06-14 13:54:55.997 INFO 71053 --- [xecute-thread-2] com.ldx.canaldemo.handler.UserHandler : update before User(id=null, username=zhangtieniu, password=null, age=28, sex=null) 2022-06-14 13:54:55.997 INFO 71053 --- [xecute-thread-2] com.ldx.canaldemo.handler.UserHandler : update after User(id=5, username=zhangsan, password=123456, age=23, sex=1) 测试删除
DELETE FROM `test`.`user` WHERE id = 5; 查看控制台输出如下
2022-06-14 13:56:46.359 INFO 71053 --- [xecute-thread-3] com.ldx.canaldemo.handler.UserHandler : delete User(id=5, username=zhangsan, password=123456, age=23, sex=1) 5. rabbit mq 测试
5.1 修改canal配置
canal.properties 修改如下
# 将serverMode 修改成rabbitMQ canal.serverMode = rabbitMQ # 添加rabbitmq 配置信息 rabbitmq.host = rabbitmq:5672 rabbitmq.virtual.host = / rabbitmq.exchange = canal.exchange rabbitmq.username = admin rabbitmq.password = admin123 example/instance.properties 添加路由规则
canal.mq.topic=canal_routing_key 5.2 springboot consumer
5.2.1 添加依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-amqp</artifactId> </dependency> 5.2.2 添加配置
spring: rabbitmq: host: localhost port: 5672 # rabbit 默认的虚拟主机 virtual-host: / # rabbit 用户名密码 username: admin password: admin123 listener: simple: # manual 手动确认 acknowledge-mode: manual 5.2.3 添加 consumer
package com.ldx.canaldemo.rabbitmq; import com.rabbitmq.client.Channel; import lombok.extern.slf4j.Slf4j; import org.springframework.amqp.core.Message; import org.springframework.amqp.core.MessageProperties; import org.springframework.amqp.rabbit.annotation.Exchange; import org.springframework.amqp.rabbit.annotation.Queue; import org.springframework.amqp.rabbit.annotation.QueueBinding; import org.springframework.amqp.rabbit.annotation.RabbitListener; import org.springframework.stereotype.Component; import java.io.IOException; /** * @author ludangxin * @date 2022/6/14 */ @Slf4j @Component public class RabbitMQConsumer { @RabbitListener(bindings = {@QueueBinding( value = @Queue(value = MqConstant.CANAL_QUEUE, durable = "true"), exchange = @Exchange(value = MqConstant.CANAL_EXCHANGE), key = MqConstant.CANAL_ROUTING_KEY) }) public void helloRabbitMq(Message message, Channel channel) throws IOException { MessageProperties messageProperties = message.getMessageProperties(); try { log.info(message.toString()); log.info(new String(message.getBody())); channel.basicAck(messageProperties.getDeliveryTag(), false); } catch(Exception e) { // 当前的消息是否重新投递的消息,也就是该消息是重新回到队列里的消息 if(messageProperties.getRedelivered()) { log.info("消息已重复处理失败,拒绝再次接收..."); // 拒绝消息Ò channel.basicReject(messageProperties.getDeliveryTag(), false); } else { log.info("消息即将再次返回队列处理..."); channel.basicNack(messageProperties.getDeliveryTag(), false, true); } } } } package com.ldx.canaldemo.rabbitmq; /** * @author ludangxin * @date 2022/6/14 */ public interface MqConstant { String CANAL_EXCHANGE = "canal.exchange"; String CANAL_QUEUE = "canal_queue"; String CANAL_ROUTING_KEY = "canal_routing_key"; } 5.3 启动测试
先启动项目让程序自动建立所需mq中的交换机和队列
测试新增
INSERT INTO `test`.`user`(`id`, `username`, `password`, `age`, `sex`) VALUES (8, 'zhangtieniu', '123456', 28, 1); 查看控制台输出如下
2022-06-14 14:42:04.818 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : (Body:'[B@189a76a(byte[414])' MessageProperties [headers={}, contentLength=0, redelivered=false, receivedExchange=canal.exchange, receivedRoutingKey=canal_routing_key, deliveryTag=4, consumerTag=amq.ctag-KXSHZ8D0wMQo7z2_L2LKsg, consumerQueue=canal_queue]) 2022-06-14 14:42:04.818 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : {"data":[{"id":"8","username":"zhangtieniu","password":"123456","age":"28","sex":"1"}],"database":"test","es":1655188924000,"id":6,"isDdl":false,"mysqlType":{"id":"int(11)","username":"varchar(255)","password":"varchar(255)","age":"int(11)","sex":"varchar(255)"},"old":null,"pkNames":["id"],"sql":"","sqlType":{"id":4,"username":12,"password":12,"age":4,"sex":12},"table":"user","ts":1655188924822,"type":"INSERT"} 测试修改
UPDATE `test`.`user` SET `username` = 'zhangsan', age = 23 WHERE id = 8; 查看控制台输出如下
2022-06-14 14:56:23.471 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : (Body:'[B@6a3a1f0(byte[446])' MessageProperties [headers={}, contentLength=0, redelivered=false, receivedExchange=canal.exchange, receivedRoutingKey=canal_routing_key, deliveryTag=5, consumerTag=amq.ctag-KXSHZ8D0wMQo7z2_L2LKsg, consumerQueue=canal_queue]) 2022-06-14 14:56:23.471 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : {"data":[{"id":"8","username":"zhangsan","password":"123456","age":"23","sex":"1"}],"database":"test","es":1655189783000,"id":7,"isDdl":false,"mysqlType":{"id":"int(11)","username":"varchar(255)","password":"varchar(255)","age":"int(11)","sex":"varchar(255)"},"old":[{"username":"zhangtieniu","age":"28"}],"pkNames":["id"],"sql":"","sqlType":{"id":4,"username":12,"password":12,"age":4,"sex":12},"table":"user","ts":1655189783493,"type":"UPDATE"} 测试删除
DELETE FROM `test`.`user` WHERE id = 8; 查看控制台输出如下
2022-06-14 14:57:06.407 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : (Body:'[B@628caa50(byte[411])' MessageProperties [headers={}, contentLength=0, redelivered=false, receivedExchange=canal.exchange, receivedRoutingKey=canal_routing_key, deliveryTag=6, consumerTag=amq.ctag-KXSHZ8D0wMQo7z2_L2LKsg, consumerQueue=canal_queue]) 2022-06-14 14:57:06.408 INFO 73549 --- [ntContainer#0-1] c.l.canaldemo.rabbitmq.RabbitMQConsumer : {"data":[{"id":"8","username":"zhangsan","password":"123456","age":"23","sex":"1"}],"database":"test","es":1655189826000,"id":8,"isDdl":false,"mysqlType":{"id":"int(11)","username":"varchar(255)","password":"varchar(255)","age":"int(11)","sex":"varchar(255)"},"old":null,"pkNames":["id"],"sql":"","sqlType":{"id":4,"username":12,"password":12,"age":4,"sex":12},"table":"user","ts":1655189826419,"type":"DELETE"} 6. canal admin管理canal
详情查看：https://gitee.com/zhengqingya/docker-compose
使用手册：https://github.com/alibaba/canal/wiki/Canal-Admin-Guide
原生安装：https://github.com/alibaba/canal/wiki/Canal-Admin-QuickStart
-
创建canal admin 数据库
canal_manager -
运行初始化sql
Liunx/canal/canal_admin/canal_manager.sql文件内容如下：
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `canal_manager` /*!40100 DEFAULT CHARACTER SET utf8 COLLATE utf8_bin */; USE `canal_manager`; SET NAMES utf8; SET FOREIGN_KEY_CHECKS = 0; -- ---------------------------- -- Table structure for canal_adapter_config -- ---------------------------- DROP TABLE IF EXISTS `canal_adapter_config`; CREATE TABLE `canal_adapter_config` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `category` varchar(45) NOT NULL, `name` varchar(45) NOT NULL, `status` varchar(45) DEFAULT NULL, `content` text NOT NULL, `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- ---------------------------- -- Table structure for canal_cluster -- ---------------------------- DROP TABLE IF EXISTS `canal_cluster`; CREATE TABLE `canal_cluster` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `name` varchar(63) NOT NULL, `zk_hosts` varchar(255) NOT NULL, `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- ---------------------------- -- Table structure for canal_config -- ---------------------------- DROP TABLE IF EXISTS `canal_config`; CREATE TABLE `canal_config` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `cluster_id` bigint(20) DEFAULT NULL, `server_id` bigint(20) DEFAULT NULL, `name` varchar(45) NOT NULL, `status` varchar(45) DEFAULT NULL, `content` text NOT NULL, `content_md5` varchar(128) NOT NULL, `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`), UNIQUE KEY `sid_UNIQUE` (`server_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- ---------------------------- -- Table structure for canal_instance_config -- ---------------------------- DROP TABLE IF EXISTS `canal_instance_config`; CREATE TABLE `canal_instance_config` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `cluster_id` bigint(20) DEFAULT NULL, `server_id` bigint(20) DEFAULT NULL, `name` varchar(45) NOT NULL, `status` varchar(45) DEFAULT NULL, `content` text NOT NULL, `content_md5` varchar(128) DEFAULT NULL, `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`), UNIQUE KEY `name_UNIQUE` (`name`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- ---------------------------- -- Table structure for canal_node_server -- ---------------------------- DROP TABLE IF EXISTS `canal_node_server`; CREATE TABLE `canal_node_server` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `cluster_id` bigint(20) DEFAULT NULL, `name` varchar(63) NOT NULL, `ip` varchar(63) NOT NULL, `admin_port` int(11) DEFAULT NULL, `tcp_port` int(11) DEFAULT NULL, `metric_port` int(11) DEFAULT NULL, `status` varchar(45) DEFAULT NULL, `modified_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; -- ---------------------------- -- Table structure for canal_user -- ---------------------------- DROP TABLE IF EXISTS `canal_user`; CREATE TABLE `canal_user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `username` varchar(31) NOT NULL, `password` varchar(128) NOT NULL, `name` varchar(31) NOT NULL, `roles` varchar(31) NOT NULL, `introduction` varchar(255) DEFAULT NULL, `avatar` varchar(255) DEFAULT NULL, `creation_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; SET FOREIGN_KEY_CHECKS = 1; -- ---------------------------- -- Records of canal_user -- ---------------------------- BEGIN; INSERT INTO `canal_user` VALUES (1, 'admin', '6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9', 'Canal Manager', 'admin', NULL, NULL, '2019-07-14 00:05:28'); COMMIT; SET FOREIGN_KEY_CHECKS = 1; -
docker-compose.yaml如下version: '3' services: canal_admin: image: canal/canal-admin:v1.1.6 container_name: canal_admin restart: unless-stopped volumes: - "./canal/canal-admin/logs:/home/admin/canal-admin/logs" environment: TZ: Asia/Shanghai LANG: en_US.UTF-8 canal.adminUser: admin canal.adminPasswd: 123456 spring.datasource.address: my_mysql:3306 spring.datasource.database: canal_manager spring.datasource.username: root spring.datasource.password: 123456 ports: - "8089:8089" networks: - canal - mysql_mysql canal_server: image: canal/canal-server:v1.1.6 container_name: canal_server restart: unless-stopped volumes: - "./canal/canal-server/logs:/home/admin/canal-server/logs" environment: TZ: Asia/Shanghai LANG: en_US.UTF-8 canal.admin.manager: canal_admin:8089 canal.admin.port: 11110 canal.admin.user: admin canal.admin.passwd: 6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 ports: - "11110:11110" - "11111:11111" - "11112:11112" depends_on: - canal_admin links: - canal_admin networks: - canal - mysql_mysql networks: canal: mysql_mysql: external: true -
启动服务/访问
http://localhost:8089/#/canalServer/nodeServers登陆 用户名/密码：admin/123456
![[Blazor] 一文理清 Blazor Identity 鉴权验证](http://www.itfaba.com/wp-content/themes/kemi/timthumb.php?src=http://www.itfaba.com/wp-content/themes/kemi/img/random/3.jpg&w=218&h=124&zc=1)
