基于canal的Redis缓存双写

canal地址：alibaba/canal: 阿里巴巴 MySQL binlog 增量订阅&消费组件 (github.com)https://github.com/alibaba/canal

1. 准备

1.1 MySQL

查看主机二进制日志

show master status

查看binlog是否开启

show variables like 'log_bin'

授权canal连接MySQL账号

CREATE USER 'canal'@'%' IDENTIFIED BY 'canal';
GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%';
FLUSH PRIVILEGES;SELECT * FROM mysql.user;

1.2 canal 

下载canal，上传redis所在服务器

 解压

修改conf/example下instance.properties

修改mysql主机ip

修改在mysql新建的canal账户 

启动

 2. canal客户端编写

新建表

CREATE TABLE `t_user` (`id` bigint(20) NOT NULL AUTO_INCREMENT,`userName` varchar(100) NOT NULL,PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8mb4

依赖

<dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>1.1.4</version>
</dependency>

package com.example.redis.utils;import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;public class RedisUtils
{public static final String  REDIS_IP_ADDR = "192.168.229.102";// public static final String  REDIS_pwd = "111111";public static JedisPool jedisPool;static {JedisPoolConfig jedisPoolConfig=new JedisPoolConfig();jedisPoolConfig.setMaxTotal(20);jedisPoolConfig.setMaxIdle(10);jedisPool=new JedisPool(jedisPoolConfig,REDIS_IP_ADDR,6379,10000);}public static Jedis getJedis() throws Exception {if(null!=jedisPool){return jedisPool.getResource();}throw new Exception("Jedispool is not ok");}}

package com.example.redis;import com.alibaba.fastjson.JSONObject;
import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.protocol.CanalEntry.*;
import com.alibaba.otter.canal.protocol.Message;
import com.example.redis.utils.RedisUtils;
import org.springframework.boot.test.context.SpringBootTest;
import redis.clients.jedis.Jedis;import java.net.InetSocketAddress;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.TimeUnit;@SpringBootTest
public class CanalTest {public static final Integer _60SECONDS = 60;public static final String  REDIS_IP_ADDR = "192.168.229.102";private static void redisInsert(List<Column> columns){JSONObject jsonObject = new JSONObject();for (Column column : columns){System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());jsonObject.put(column.getName(),column.getValue());}if(columns.size() > 0){try(Jedis jedis = RedisUtils.getJedis()){jedis.set(columns.get(0).getValue(),jsonObject.toJSONString());}catch (Exception e){e.printStackTrace();}}}private static void redisDelete(List<Column> columns){JSONObject jsonObject = new JSONObject();for (Column column : columns){jsonObject.put(column.getName(),column.getValue());}if(columns.size() > 0){try(Jedis jedis = RedisUtils.getJedis()){jedis.del(columns.get(0).getValue());}catch (Exception e){e.printStackTrace();}}}private static void redisUpdate(List<Column> columns){JSONObject jsonObject = new JSONObject();for (Column column : columns){System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());jsonObject.put(column.getName(),column.getValue());}if(columns.size() > 0){try(Jedis jedis = RedisUtils.getJedis()){jedis.set(columns.get(0).getValue(),jsonObject.toJSONString());System.out.println("---------update after: "+jedis.get(columns.get(0).getValue()));}catch (Exception e){e.printStackTrace();}}}public static void printEntry(List<Entry> entrys) {for (Entry entry : entrys) {if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {continue;}RowChange rowChage = null;try {//获取变更的row数据rowChage = RowChange.parseFrom(entry.getStoreValue());} catch (Exception e) {throw new RuntimeException("ERROR ## parser of eromanga-event has an error,data:" + entry.toString(),e);}//获取变动类型EventType eventType = rowChage.getEventType();System.out.println(String.format("================&gt; binlog[%s:%s] , name[%s,%s] , eventType : %s",entry.getHeader().getLogfileName(), entry.getHeader().getLogfileOffset(),entry.getHeader().getSchemaName(), entry.getHeader().getTableName(), eventType));for (RowData rowData : rowChage.getRowDatasList()) {if (eventType == EventType.INSERT) {redisInsert(rowData.getAfterColumnsList());} else if (eventType == EventType.DELETE) {redisDelete(rowData.getBeforeColumnsList());} else {//EventType.UPDATEredisUpdate(rowData.getAfterColumnsList());}}}}public static void main(String[] args){System.out.println("---------O(∩_∩)O哈哈~ initCanal() main方法-----------");//=================================// 创建链接canal服务端CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(REDIS_IP_ADDR,11111), "example", "", "");int batchSize = 1000;//空闲空转计数器int emptyCount = 0;System.out.println("---------------------canal init OK，开始监听mysql变化------");try {connector.connect();//connector.subscribe(".*\\..*");connector.subscribe("redis_canal.t_user");connector.rollback();int totalEmptyCount = 10 * _60SECONDS;while (emptyCount < totalEmptyCount) {System.out.println("我是canal，每秒一次正在监听:"+ UUID.randomUUID().toString());Message message = connector.getWithoutAck(batchSize); // 获取指定数量的数据long batchId = message.getId();int size = message.getEntries().size();if (batchId == -1 || size == 0) {emptyCount++;try { TimeUnit.SECONDS.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); }} else {//计数器重新置零emptyCount = 0;printEntry(message.getEntries());}connector.ack(batchId); // 提交确认// connector.rollback(batchId); // 处理失败, 回滚数据}System.out.println("已经监听了"+totalEmptyCount+"秒，无任何消息，请重启重试......");} finally {connector.disconnect();}}}

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>3.3.3</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.example</groupId><artifactId>Redis</artifactId><version>0.0.1-SNAPSHOT</version><name>Redis</name><description>Redis</description><url/><licenses><license/></licenses><developers><developer/></developers><scm><connection/><developerConnection/><tag/><url/></scm><properties><java.version>17</java.version></properties><dependencies><!--SpringBoot通用依赖模块--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-pool2</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.28</version><scope>compile</scope></dependency><dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>1.1.4</version></dependency><!-- 数据库相关配置启动器 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><!-- druid启动器的依赖  --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-3-starter</artifactId><version>1.2.18</version></dependency><!-- 驱动类--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version></dependency><dependency><groupId>redis.clients</groupId><artifactId>jedis</artifactId><version>3.8.0</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>2.0.0</version></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

spring.application.name=Redis
server.port=8080# ========================redis??=====================
spring.data.redis.database=0
spring.data.redis.host=192.168.229.102
spring.data.redis.port=6379
spring.data.redis.lettuce.pool.max-active=8
spring.data.redis.lettuce.pool.max-wait=-1ms
spring.data.redis.lettuce.pool.max-idle=8
spring.data.redis.lettuce.pool.min-idle=0# ========================alibaba.druid=====================
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/redis_canal?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=abc123
spring.datasource.druid.test-while-idle=false

canal启动失败可能是没有durid依赖，将durid放入lib下即可

Central Repository: com/alibaba/druid/1.2.22 (maven.org)https://repo1.maven.org/maven2/com/alibaba/druid/1.2.22/