2.Mysql集群------Mycat读写分离

前言：

Mycat：

一个彻底开源的，面向企业应用开发的大数据库集群

支持事务、ACID、可以替代MySQL的加强版数据库

一个可以视为MySQL集群的企业级数据库，用来替代昂贵的Oracle集群

一个融合内存缓存技术、NoSQL技术、HDFS大数据的新型SQL Server

结合传统数据库和新型分布式数据仓库的新一代企业级数据库产品

一个新颖的数据库中间件产品

......

关于mycat更多的介绍，及文档，请点击Mycat官网

准备工作：

1、安装JDK：参考

2、安装Mycat：参考

3、配置数据库的主从同步：参考

开始搬砖：

1.配置/conf/schema.xml

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

    <!-- 配置逻辑库XMDB -->
    <schema name="XMDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1" />
    <!-- 映射到你实际数据库中的库名：xm -->
    <dataNode name="dn1" dataHost="node1" database="xm"/>
    <!-- 配置Host，设置数据库的参数 -->
    <dataHost name="node1" maxCon="1000" minCon="10" balance="1" dbType="mysql" dbDriver="native">
        <!-- 心跳检测,来看下面的host是否还可用 -->
        <heartbeat>select user()</heartbeat>
        <!-- 读写分离 -->
        <writeHost host="192.168.40.3" url="192.168.40.3:3306" user="root" password="123456">
            <readHost  host="192.168.40.3" url="192.168.40.3:3316" user="root" password="123456" />
        </writeHost>
        <writeHost host="192.168.40.3" url="192.168.40.3:3316" 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>

2.配置/conf/server.xml

 <?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="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="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-->
         <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">1</property>

         <!--
             单位为m
         -->
         <property name="memoryPageSize">1m</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">true</property>

     </system>

     <!-- 全局SQL防火墙设置 -->
     <!--
     <firewall>
        <whitehost>
           <host host="127.0.0.1" user="mycat"/>
           <host host="127.0.0.2" user="mycat"/>
        </whitehost>
        <blacklist check="false">
        </blacklist>
     </firewall>
     -->

     <!-- 配置用户 -->

     <user name="root">
         <property name="password">123456</property>
         <property name="schemas">XMDB</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">XMDB</property>
         <property name="readOnly">true</property>
     </user>

 </mycat:server>

3.开启mycat服务

：mycat start

4.查看开启状况/logs/wrapper.log

日志里会描述开启状况，及异常错误。

开启成功。

5.连接客户端测试读写分离。