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 INTO user (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
来源：oschina
链接：https://my.oschina.net/u/4270565/blog/3685746