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MyCat如何实现MySQL双主一从读写分离

发表于：2026-11-02 作者：千家信息网编辑

千家信息网最后更新 2026年11月02日，这篇文章给大家分享的是有关MyCat如何实现MySQL双主一从读写分离的内容。小编觉得挺实用的，因此分享给大家做个参考，一起跟随小编过来看看吧。1）配置server.xml

千家信息网最后更新 2026年11月02日MyCat如何实现MySQL双主一从读写分离

这篇文章给大家分享的是有关MyCat如何实现MySQL双主一从读写分离的内容。小编觉得挺实用的，因此分享给大家做个参考，一起跟随小编过来看看吧。

1）配置server.xml

                mysql                TESTDB

配置用户root，密码为mysql，对TESTDB具有权限

2）配置schema.xml

                                                                select user()

schema标签：schema name属性指定逻辑库名，dataNode属性指定下边的dataNode

dataNode标签：dataHost指定下边的dataHost，database指定具体的database

dataHost标签：balance指的负载均衡类型，switchType指的是切换的模式

balance指的负载均衡类型，目前的取值有4种：

1. balance="0", 不开启读写分离机制，所有读操作都发送到当前可用的writeHost上。

2. balance="1"，全部的readHost与stand by writeHost参与select语句的负载均衡。

3. balance="2"，所有读操作都随机的在writeHost、readhost上分发。

4. balance="3"，所有读请求随机的分发到wiriterHost对应的readhost执行，writerHost不负担读压力

switchType指的是切换的模式，目前的取值也有4种：

1. switchType='-1' 表示不自动切换

2. switchType='1' 默认值，表示自动切换

3. switchType='2' 基于MySQL主从同步的状态决定是否切换,心跳语句为 show slave status

4. switchType='3'基于MySQL galary cluster的切换机制（适合集群）（1.4.1），心跳语句为 show status like 'wsrep%'。

3）启动mycat，并观察日志

/usr/local/mycat/bin/mycat start

[root@oneproxy logs]# tail -f wrapper.log STATUS | wrapper  | 2018/08/25 10:32:39 | --> Wrapper Started as DaemonSTATUS | wrapper  | 2018/08/25 10:32:40 | Launching a JVM...INFO   | jvm 1    | 2018/08/25 10:32:40 | Wrapper (Version 3.2.3) http://wrapper.tanukisoftware.orgINFO   | jvm 1    | 2018/08/25 10:32:40 |   Copyright 1999-2006 Tanuki Software, Inc.  All Rights Reserved.INFO   | jvm 1    | 2018/08/25 10:32:40 | INFO   | jvm 1    | 2018/08/25 10:32:41 | log4j:WARN No appenders could be found for logger (io.mycat.memory.MyCatMemory).INFO   | jvm 1    | 2018/08/25 10:32:41 | log4j:WARN Please initialize the log4j system properly.INFO   | jvm 1    | 2018/08/25 10:32:41 | log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.INFO   | jvm 1    | 2018/08/25 10:32:41 | MyCAT Server startup successfully. see logs in logs/mycat.log

4）在mycat服务器登录mysql

mysql -uroot -pmysql -P8066 -h292.168.8.63

mysql> show databases;

+----------+

| DATABASE |

+----------+

| TESTDB |

+----------+

5）测试读写分离

mysql> use TESTDB;mysql> create table t4(hostname1 varchar(12),hostname2 varchar(12),hostname3 varchar(12));mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);mysql> mysql> insert into t4 values(@@hostname,@@hostname,@@hostname);

mysql> select * from t4;+-----------+-----------+-----------+| hostname1 | hostname2 | hostname3 |+-----------+-----------+-----------+| master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   || master1   | master1   | master1   |+-----------+-----------+-----------+64 rows in set (0.00 sec)

插入的数据都是从master1插入的，通过查询mycat日志，发现所有的查询全部分发到了slave节点。

感谢各位的阅读！关于"MyCat如何实现MySQL双主一从读写分离"这篇文章就分享到这里了，希望以上内容可以对大家有一定的帮助，让大家可以学到更多知识，如果觉得文章不错，可以把它分享出去让更多的人看到吧！

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