安装mycat，配置

首先安装好mysql集群，

做了1主2从的，读写分离的配置，见上篇博文

安装mycat，

解压Mycat-server-1.6.7.1-release-20190627191042-linux.tar.gz

得到 mycat 文件夹

启动，进入 bin/，

./mycat start

进入logs，查看 wrapper.log 可以看到启动日志，

配置： 

修改schema.xml 文件，这个是表的主文件

主库文件为 ZHOUYI2,大小写敏感，且必须为大写。这个配置是一个dn节点，没有分片，只是做了读写分离，且写服务器肩负读。

<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">

    <schema name="ZHOUYI2" checkSQLschema="false" sqlMaxLimit="10000">
        <table name="tbl_zhanbuHit" dataNode="dn1" />
        <table name="tbl_admin" dataNode="dn1" />
        <table name="tbl_authc" dataNode="dn1"/>
        <table name="tbl_author" dataNode="dn1"/>
        <table name="tbl_category" dataNode="dn1"/>
        <table name="tbl_content" dataNode="dn1"/>
        <table name="tbl_description" dataNode="dn1"/>
        <table name="tbl_domain" dataNode="dn1"/>

        <table name="tbl_history" dataNode="dn1"/>
        <table name="tbl_index" dataNode="dn1"/>
        <table name="tbl_others" dataNode="dn1"/>
        <table name="tbl_role" dataNode="dn1"/>
        <table name="tbl_yao" dataNode="dn1"/>
    </schema>
    <!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743"
        /> -->
    <dataNode name="dn1" dataHost="localhost1" database="zhouyi2" />
    <!--<dataNode name="dn4" dataHost="sequoiadb1" database="SAMPLE" />
     <dataNode name="jdbc_dn1" dataHost="jdbchost" database="db1" />
    <dataNode    name="jdbc_dn2" dataHost="jdbchost" database="db2" />
    <dataNode name="jdbc_dn3"     dataHost="jdbchost" database="db3" /> -->
    <dataHost name="localhost1" maxCon="1000" minCon="10" balance="0"
              writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
        <heartbeat>select user()</heartbeat>
        <!-- can have multi write hosts -->
        <writeHost host="hostM1" url="172.16.0.230:3306" user="root"
                   password="xxxxx">
            <!-- can have multi read hosts -->
            <readHost host="hostM1r" url="172.16.0.230:3306" user="root" password="xxxx"></readHost>    
            <readHost host="hostS2" url="172.16.0.232:3306" user="root" password="xxxx" />
            <readHost host="hostS1" url="172.16.0.231:3306" user="root" password="xxxx"/>    
        </writeHost>
        <!-- <writeHost host="hostM2" url="localhost:3316" user="root" password="123456"/> -->
    </dataHost>
    <!--
        <dataHost name="sequoiadb1" maxCon="1000" minCon="1" balance="0" dbType="sequoiadb" dbDriver="jdbc">
        <heartbeat>         </heartbeat>
         <writeHost host="hostM1" url="sequoiadb://1426587161.dbaas.sequoialab.net:11920/SAMPLE" user="jifeng"     password="jifeng"></writeHost>
         </dataHost>

      <dataHost name="oracle1" maxCon="1000" minCon="1" balance="0" writeType="0"     dbType="oracle" dbDriver="jdbc"> <heartbeat>select 1 from dual</heartbeat>
        <connectionInitSql>alter session set nls_date_format='yyyy-mm-dd hh24:mi:ss'</connectionInitSql>
        <writeHost host="hostM1" url="jdbc:oracle:thin:@127.0.0.1:1521:nange" user="base"     password="123456" > </writeHost> </dataHost>

        <dataHost name="jdbchost" maxCon="1000"     minCon="1" balance="0" writeType="0" dbType="mongodb" dbDriver="jdbc">
        <heartbeat>select     user()</heartbeat>
        <writeHost host="hostM" url="mongodb://192.168.0.99/test" user="admin" password="123456" ></writeHost> </dataHost>

        <dataHost name="sparksql" maxCon="1000" minCon="1" balance="0" dbType="spark" dbDriver="jdbc">
        <heartbeat> </heartbeat>
         <writeHost host="hostM1" url="jdbc:hive2://feng01:10000" user="jifeng"     password="jifeng"></writeHost> </dataHost> -->

    <!-- <dataHost name="jdbchost" maxCon="1000" minCon="10" balance="0" dbType="mysql"
        dbDriver="jdbc"> <heartbeat>select user()</heartbeat> <writeHost host="hostM1"
        url="jdbc:mysql://localhost:3306" user="root" password="123456"> </writeHost>
        </dataHost> -->
</mycat:schema>

另外，需要配置 server.xml

这里配置有两个地方，需要改为 ZHOUYI2,必须大写

一个是root的账号，一个是user的账号。

<?xml version="1.0" encoding="UTF-8"?>
<!-- - - Licensed under the Apache License, Version 2.0 (the "License"); 
    - you may not use this file except in compliance with the License. - You 
    may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 
    - - Unless required by applicable law or agreed to in writing, software - 
    distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT 
    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the 
    License for the specific language governing permissions and - limitations 
    under the License. -->
<!DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://io.mycat/">
    <system>
    <property name="nonePasswordLogin">0</property> <!-- 0为需要密码登陆、1为不需要密码登陆 ,默认为0，设置为1则需要指定默认账户-->
    <property name="useHandshakeV10">1</property>
    <property name="useSqlStat">0</property>  <!-- 1为开启实时统计、0为关闭 -->
    <property name="useGlobleTableCheck">0</property>  <!-- 1为开启全加班一致性检测、0为关闭 -->

        <property name="sequnceHandlerType">2</property>
        <!--<property name="sequnceHandlerPattern">(?:(s*nexts+values+fors*MYCATSEQ_(w+))(,|)|s)*)+</property>-->
        <!--必须带有MYCATSEQ_或者 mycatseq_进入序列匹配流程 注意MYCATSEQ_有空格的情况-->
        <property name="sequnceHandlerPattern">(?:(s*nexts+values+fors*MYCATSEQ_(w+))(,|)|s)*)+</property>
    <property name="subqueryRelationshipCheck">false</property> <!-- 子查询中存在关联查询的情况下,检查关联字段中是否有分片字段 .默认 false -->
      <!--  <property name="useCompression">1</property>--> <!--1为开启mysql压缩协议-->
        <!--  <property name="fakeMySQLVersion">5.6.20</property>--> <!--设置模拟的MySQL版本号-->
    <!-- <property name="processorBufferChunk">40960</property> -->
    <!-- 
    <property name="processors">1</property> 
    <property name="processorExecutor">32</property> 
     -->
        <!--默认为type 0: DirectByteBufferPool | type 1 ByteBufferArena | type 2 NettyBufferPool -->
        <property name="processorBufferPoolType">0</property>
        <!--默认是65535 64K 用于sql解析时最大文本长度 -->
        <!--<property name="maxStringLiteralLength">65535</property>-->
        <!--<property name="sequnceHandlerType">0</property>-->
        <!--<property name="backSocketNoDelay">1</property>-->
        <!--<property name="frontSocketNoDelay">1</property>-->
        <!--<property name="processorExecutor">16</property>-->
        <!--
            <property name="serverPort">8066</property> <property name="managerPort">9066</property> 
            <property name="idleTimeout">300000</property> <property name="bindIp">0.0.0.0</property> 
            <property name="frontWriteQueueSize">4096</property> <property name="processors">32</property> -->
        <!--分布式事务开关，0为不过滤分布式事务，1为过滤分布式事务（如果分布式事务内只涉及全局表，则不过滤），2为不过滤分布式事务,但是记录分布式事务日志-->
        <property name="handleDistributedTransactions">0</property>
        
            <!--
            off heap for merge/order/group/limit      1开启   0关闭
        -->
        <property name="useOffHeapForMerge">0</property>

        <!--
            单位为m
        -->
        <property name="memoryPageSize">64k</property>

        <!--
            单位为k
        -->
        <property name="spillsFileBufferSize">1k</property>

        <property name="useStreamOutput">0</property>

        <!--
            单位为m
        -->
        <property name="systemReserveMemorySize">384m</property>


        <!--是否采用zookeeper协调切换  -->
        <property name="useZKSwitch">false</property>

        <!-- XA Recovery Log日志路径 -->
        <!--<property name="XARecoveryLogBaseDir">./</property>-->

        <!-- XA Recovery Log日志名称 -->
        <!--<property name="XARecoveryLogBaseName">tmlog</property>-->
        <!--如果为 true的话 严格遵守隔离级别,不会在仅仅只有select语句的时候在事务中切换连接-->
        <property name="strictTxIsolation">false</property>
        
        <property name="useZKSwitch">true</property>
        
    </system>
    
    <!-- 全局SQL防火墙设置 -->
    <!--白名单可以使用通配符%或着*-->
    <!--例如<host host="127.0.0.*" user="root"/>-->
    <!--例如<host host="127.0.*" user="root"/>-->
    <!--例如<host host="127.*" user="root"/>-->
    <!--例如<host host="1*7.*" user="root"/>-->
    <!--这些配置情况下对于127.0.0.1都能以root账户登录-->
    <!--
    <firewall>
       <whitehost>
          <host host="1*7.0.0.*" user="root"/>
       </whitehost>
       <blacklist check="false">
       </blacklist>
    </firewall>
    -->

    <user name="root" defaultAccount="true">
        <property name="password">123456</property>
        <property name="schemas">ZHOUYI2</property>
        
        <!-- 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">ZHOUYI2</property>
        <property name="readOnly">true</property>
    </user>

</mycat:server>

java连接的时候，和普通的mysql连接一样。只要把连接字符串改一下（库名必须大写），并且把端口号改为8066，即可。