mycat配置MySQL主从读写分离

1.安装java 1.8

mycat 1.6要求的Java需要Java 1.8或1.8以上，安装Java参考以下链接：
https://blog.csdn.net/weixin_43893397/article/details/102636437

　　

2.配置主从复制，主库创建远程用户用作数据连接

grant all on *.* to 'root'@'192.168.12.%' identified by 'mysql';

　　

3.上传，解压mycat安装包

4.修改root，mysql用户环境变量

vim /etc/profile
export JAVA_HOME=/stage/jdk1.8.0_144
export PATH=/stage/jdk1.8.0_144/bin:$PATH
 
vim /home/mysql/.bash_profile
export PATH
export JAVA_HOME=/stage/jdk1.8.0_144
export PATH=/usr/local/mysql/bin:$PATH
export PATH=/stage/mycat/bin:$PATH
export PATH=/stage/jdk1.8.0_144/bin:/stage/mycat/bin:/usr/local/mysql/bin:$PATH

　　 

5.修改mycat配置文件

修改server.xml
 <user name="root" defaultAccount="true">
        <property name="password">123456</property>
        <property name="schemas">csg</property>
        <property name="defaultSchema">csg</property>
        <!--No MyCAT Database selected 错误前会尝试使用该schema作为schema，不设置则为null,报错 -->
        <!-- 表级 DML 权限设置 -->
        <!--        
        <privileges check="false">
            <schema name="TESTDB" dml="0110" >
                <table name="tb01" dml="0000"></table>
                <table name="tb02" dml="1111"></table>
            </schema>
        </privileges>       
         -->
    </user>
    <user name="user">
        <property name="password">user</property>
        <property name="schemas">csg</property>
        <property name="readOnly">true</property>
        <property name="defaultSchema">csg</property>
    </user>
</mycat:server>

修改schema.xml
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
    <schema name="csg" checkSQLschema="true" sqlMaxLimit="100" dataNode="dn1">
    </schema>
    <dataNode name="dn1" dataHost="localhost1" database="csg" />
    <dataHost name="localhost1" maxCon="1000" minCon="10" balance="3"
              writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
        <heartbeat>select user()</heartbeat>
        <writeHost host="hostM1" url="192.168.12.60:3306" user="root" password="mysql">
        <readHost host="readS2" url="192.168.12.3:3306" user="root" password="mysql" />
        </writeHost>
    </dataHost>
</mycat:schema>

多个只读库，直接加一列，如：
<readHost host="readS3" url="192.168.12.4:3306" user="root" password="mysql" />
<readHost host="readS4" url="192.168.12.5:3306" user="root" password="mysql" />