mycat 分库配置-取模分片规则

0.前提条件

前期工作

1.修改schema.xml

<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
 
	<schema name="MYCAT_DB" checkSQLschema="false" sqlMaxLimit="100">
		<!-- auto sharding by id (long) -->
		<table name="travelrecord" dataNode="dn1,dn2" rule="auto-sharding-long" />
		<table name="user" primaryKey="ID" autoIncrement="true" dataNode="dn1,dn2"
			   rule="mod-long" />
	</schema>
 
	<dataNode name="dn1" dataHost="win-local" database="db1" />
	<dataNode name="dn2" dataHost="centos-local" database="db1" />
 
	<dataHost name="win-local" maxCon="1000" minCon="10" balance="0"
			  writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<writeHost host="win-local-M" url="196.168.1.104:3306" user="root"
				   password="*******">
		</writeHost>
	</dataHost>
	<dataHost name="centos-local" maxCon="1000" minCon="10" balance="0"
			  writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<writeHost host="centos-local-M" url="192.168.1.60:3306" user="root"
				   password="******">
		</writeHost>
	</dataHost>
</mycat:schema>

2. 修改rule.xml

        <tableRule name="mod-long">
                <rule>
                        <columns>id</columns>
                        <algorithm>mod-long</algorithm>
                </rule>
        </tableRule>

        <function name="mod-long" class="io.mycat.route.function.PartitionByMod">
                <!-- how many data nodes -->
                <property name="count">2</property>
        </function>

3.默认的auto-sharding-long 有三个节点，现在实际只设置了两个节点

[root@base-linux conf]# vi autopartition-long.txt 

3.启动mycat

[root@base-linux conf]# /usr/local/src/mycat/bin/mycat console start

4.使用navicat连接mycat

     1)创建user表

create table user(id bigint not null auto_increment primary key,name varchar(100));

        2)在两个节点都创建了user表  (id%2 == 1 -->dn1   id%2 == 0 -->dn2 )