mycat快速入门之读写分离

mycat主要是提供了数据库库切分的一种具体实现配置，这一篇咱们不作深刻剖析，先让程序跑起来再说！

mycat官网：http://www.mycat.io/  #中文的别怕

 1>环境：

CentOS操做系统
mysql5.6
主库主机：192.168.0.1
从库a主机：192.168.0.2
从库b主机：192.168.0.3

因为测试，我没开太多虚拟机，全部把mycat服务器和从库b装在了一台机器上了

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2>配置mycat先确保，配置好主从复制，半同步复制。（我以前博文有讲详细步骤）

3>开始配置mycat

(1)先安装JDK(由于mycat是用java实现的)

JDK 下载：http://www.oracle.com/technetwork/java/javase/downloads/ 

(2)在安装mycat

官网下载并解压：tar -zxvf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz 

(3)#配置/etc/profile

export JAVA_HOME=/usr/app/jdk1.8.0_171
export JRE_HOME=/usr/app/jdk1.8.0_171/jre
export MYCAT_HOME=/usr/app/mycat
export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin:$MYCAT_HOME/bin 

(4)mycat配置(先备份三个配置文件)

>>cd /d/mycat/conf
>>ls
rule.xml
server.xml
schema.xml 

server.xml

<!-- 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>
        -->

        <user name="root">
                <property name="password">123456</property>
                <property name="schemas">contract0</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">contract0</property>
                <property name="readOnly">true</property>
        </user>

 schema.xml

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

        <schema name="contract0" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1">
        </schema>
        <dataNode name="dn1" dataHost="localhost1" database="contract0" />
        <dataHost name="localhost1" maxCon="100" minCon="4" balance="3"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <!-- can have multi write hosts -->
                <writeHost host="hostM1" url="192.168.0.1:3306" user="root"
                                   password="123123">
                        <!-- can have multi read hosts -->
                        <readHost host="hostS1" url="192.168.0.2:3306" user="root" password="123123" weight="1"/>
                        <readHost host="hostS2" url="192.168.0.1:3306" user="root" password="123123" weight="1"/>
                </writeHost>
        </dataHost>
</mycat:schema>

4>安装完成后，启动:
>>mycat --help
Usage: /d/mycat/bin/mycat { console | start | stop | restart | status | dump }
>>mycat start

OK，能够跑起来了！后续博文将详细介绍mycat！！