使用Canal实现redis和mysql的同步

### canal 工作思路

Canal 会将自己伪装成 MySQL 从节点（Slave），并从主节点（Master）获取 Binlog，解析和贮存后供下游消费端使用。Canal 包含两个组成部分：服务端和客户端。服务端负责连接至不同的 MySQL 实例，并为每个实例维护一个事件消息队列；客户端则可以订阅这些队列中的数据变更事件，处理并存储到数据仓库中。下面我们将mysql同步到 redis

mysql版本 5.6

canal版本 1.1.0

安装 mysql 后修改自己mysql配置

vim /etc/my.cnf

# 开启mysql的binlog模块
log-bin=mysql-bin
binlog-format=ROW
# server_id需保证唯一，不能和canal的slaveId重复
server_id=121
# 需要同步的数据库名称
binlog-do-db=test_canal
# 忽略的数据库，建议填写
binlog-ignore-db=mysql
# 启动mysql时不启动grant-tables授权表
skip-grant-tables

创建一个mysql用户canal 并且赋远程链接权限权限，和测试库test_canal,

CREATE USER canal IDENTIFIED BY 'canal';
GRANT ALL PRIVILEGES ON test_canal.user TO 'canal'@'%';
FLUSH PRIVILEGES;

使用root账户进去看看
select * from mysql.user where user=’canal’ \G其查询结果列表中Repl_slave_priv,Repl_client_priv中的为Y是对的,查看主从备份如下图：

Canal部分

下载canal：https://github.com/alibaba/canal/releases/

下载版本为1.1.0，解压即可

tar -zxvf canal.deployer-1.1.0.tar.gz -C /usr/local/cancal/

解压后得到四个目录bin、conf、lib、logs
基本上配置都在一下两个配置文件中

canal.properties无需修改，instance.properties需要配置所同步的组件

instance.properties配置如下

#################################################
## mysql serverId , v1.0.26+ will autoGen 
#与mysql配置文件一致
canal.instance.mysql.slaveId=121# enable gtid use true/false
canal.instance.gtidon=false# position info
canal.instance.master.address=ip:3306
canal.instance.master.journal.name=
canal.instance.master.position=
canal.instance.master.timestamp=
canal.instance.master.gtid=# rds oss binlog
canal.instance.rds.accesskey=
canal.instance.rds.secretkey=
canal.instance.rds.instanceId=# table meta tsdb info 
#暂时用不上设为false
canal.instance.tsdb.enable=false
canal.instance.tsdb.dir=${canal.file.data.dir:../conf}/${canal.instance.destination:}
canal.instance.tsdb.url=jdbc:h2:${canal.instance.tsdb.dir}/h2;CACHE_SIZE=1000;MODE=MYSQL;
#canal.instance.tsdb.url=jdbc:mysql://127.0.0.1:3306/canal_tsdb
canal.instance.tsdb.dbUsername=canal
canal.instance.tsdb.dbPassword=canal#canal.instance.standby.address =
#canal.instance.standby.journal.name =
#canal.instance.standby.position = 
#canal.instance.standby.timestamp =
#canal.instance.standby.gtid=# username/password
canal.instance.dbUsername=canal
canal.instance.dbPassword=canal
canal.instance.defaultDatabaseName=test_canal
canal.instance.connectionCharset=UTF-8# table regex
canal.instance.filter.regex=.*\\..*
# table black regex
canal.instance.filter.black.regex=
#################################################

查看日志是否启动成功:logs/canal/canal.log 和logs/example/example.log

logs/canal/canal.log文件中有如下内容：the canal server is running now ......
logs/example/example.log文件中有如下内容：start successful....

Java的canal客户端和jedis

在项目maven中添加redis和canal依赖

<dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>1.0.25</version></dependency><dependency><groupId>redis.clients</groupId><artifactId>jedis</artifactId><version>2.9.0</version></dependency>

redis工具类：

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;/*** @author lgz*/
public class RedisUtil {private static Jedis jedis = null;public static synchronized Jedis getJedis() {if (jedis == null) {jedis = new Jedis("192.168.188.128", 6379);jedis.auth("redis1234");}return jedis;}public static boolean existKey(String key) {return getJedis().exists(key);}public static void delKey(String key) {getJedis().del(key);}public static String stringGet(String key) {return getJedis().get(key);}public static String stringSet(String key, String value) {return getJedis().set(key, value);}public static void hashSet(String key, String field, String value) {getJedis().hset(key, field, value);}
}

canal客户端：

package com.wlx.demo.config;
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 java.net.InetSocketAddress;
import java.util.List;
/*** Created by zhangpan on 2019/1/4.*/
public class CanalApplication {public static void main(String args[]) {CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("ip",11111), "example", "", "");int batchSize = 100;try {connector.connect();connector.subscribe(".*\\..*");connector.rollback();while (true) {// 获取指定数量的数据Message message = connector.getWithoutAck(batchSize);long batchId = message.getId();int size = message.getEntries().size();System.out.println("batchId = " + batchId);System.out.println("size = " + size);if (batchId == -1 || size == 0) {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}} else {printEntry(message.getEntries());}// 提交确认connector.ack(batchId);// connector.rollback(batchId); // 处理失败, 回滚数据}} finally {connector.disconnect();}}private static void printEntry(List<Entry> entrys) {for (Entry entry : entrys) {if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {continue;}RowChange rowChage = null;try {rowChage = RowChange.parseFrom(entry.getStoreValue());} catch (Exception e) {throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),e);}EventType eventType = rowChage.getEventType();System.out.println(String.format("================> 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.DELETE) {redisDelete(rowData.getBeforeColumnsList());} else if (eventType == EventType.INSERT) {redisInsert(rowData.getAfterColumnsList());} else {System.out.println("-------> before");printColumn(rowData.getBeforeColumnsList());System.out.println("-------> after");redisUpdate(rowData.getAfterColumnsList());}}}}private static void printColumn(List<Column> columns) {for (Column column : columns) {System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());}}private static void redisInsert(List<Column> columns) {JSONObject json = new JSONObject();for (Column column : columns) {json.put(column.getName(), column.getValue());}if (columns.size() > 0) {RedisUtil.stringSet("user:" + columns.get(0).getValue(), json.toJSONString());}}private static void redisUpdate(List<Column> columns) {JSONObject json = new JSONObject();for (Column column : columns) {json.put(column.getName(), column.getValue());}if (columns.size() > 0) {RedisUtil.stringSet("user:" + columns.get(0).getValue(), json.toJSONString());}}private static void redisDelete(List<Column> columns) {JSONObject json = new JSONObject();for (Column column : columns) {json.put(column.getName(), column.getValue());}if (columns.size() > 0) {RedisUtil.delKey("user:" + columns.get(0).getValue());}}
}

在test_canal新建user表，

CREATE TABLE `user` (`id` int(11) NOT NULL,`name` varchar(255) DEFAULT NULL,PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

添加数据可以在控制台看到消息：
INSERT INTOuser(id,name) VALUES (1,'zhangpan');

控制台消息

size = 3
================> binlog[mysql-bin.000005:5001] , name[test_canal,user] , eventType : INSERT

参考博客：https://blog.csdn.net/lyl0724/article/details/80528428
转载请说明出处！谢谢，本文地址：https://www.cnblogs.com/ontoweb-zp/p/10232017.html

转载于:https://www.cnblogs.com/ontoweb-zp/p/10232017.html