Mycat数据库中间件对Mysql读写分离和分库分表配置

Mycat是一个开源的分布式数据库系统，不同于oracle和mysql，Mycat并没有存储引擎，但是Mycat实现了mysql协议，前段用户可以把它当做一个Proxy。其核心功能是分表分库，即将一个大表水平分割为N个小表，存储在后端mysql存储引擎里面。最新版本的Mycat不仅支持mysql，还可以支持MS SqlServer,Oracle,DB2等关系型数据库，而且还支持MongoDB这种NoSQL。Mycat对调用者屏蔽了后端存储具体实现。

Mycat的原理是先拦截用户的SQL语句并做分析：分片分析，路由分析，读写分离分析，缓存分析等，再对将该SQL语句发送到指定规则的数据库。最终将存储引擎返回的结果返回给用户.

本次搭建的Mycat读写分离和分库分表配置是基于5台服务器（1台Mac,4台Centos），架构图如下，Mac服务器上面安装Mycat；M1(OS名称：Server1,Ip:172.16.130.189)和M2(OS名称：Server2,Ip:172.16.130.190)是两个写节点; S1(OS名称：Server3,Ip:172.16.130.191)和S2(OS名称：Server4,Ip:172.16.130.192)是两个读节点。且M1和S1配置了主从复制，M2和S2也配置了主从复制。

步骤

1.在Server1,Server2,Server3和Server4中安装相同版本的Mysql，安装步骤在我之前的一篇文章中：四·安装mysql-5.7.16-linux-glibc2.5-x86_64.tar.gz（基于Centos7源码安装）

2.配置Server3同步Server1；Server4同步Server2,在我的另外一篇文章中：一.Mysql主从复制配置

其中关键代码如下

--------------------------------------Server1配置-----------------------------------------------------------
mysql> grant replication slave on *.* to 'mysqlsync'@'172.16.130.191' identified by 'mysqlsync';
Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> show master status;
+------------+----------+--------------+------------------+-------------------+
| File       | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------+----------+--------------+------------------+-------------------+
| bin.000003 |      455 |              |                  |                   |
+------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

--------------------------------------Server3配置-----------------------------------------------------------

mysql> change master to master_host='172.16.130.189',master_user='mysqlsync',master_password='mysqlsync',master_log_file='bin.000003',master_log_pos=154;
  Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> start slave;
  Query OK, 0 rows affected (0.00 sec)

3.在Server1和Server2上面分别新建一个名为mycattest的schema，且配置的访问用户名为mycattest,密码为1234
4.修改wapper.cnf

#********************************************************************
# Wrapper Properties
#********************************************************************
# Java Application
wrapper.java.command=/Library/Java/JavaVirtualMachines/jdk1..0_79.jdk/Contents/Home/bin/java
wrapper.working.dir=..

# Java Main class.  This class must implement the WrapperListener interface
#  or guarantee that the WrapperManager class is initialized.  Helper
#  classes are provided to do this for you.  See the Integration section
#  of the documentation for details.
wrapper.java.mainclass=org.tanukisoftware.wrapper.WrapperSimpleApp
set.default.REPO_DIR=lib
set.APP_BASE=.

# Java Classpath (include wrapper.jar)  Add class path elements as
#  needed starting from
wrapper.java.classpath.=lib/wrapper.jar
wrapper.java.classpath.=conf
wrapper.java.classpath.=%REPO_DIR%/*

# Java Library Path (location of Wrapper.DLL or libwrapper.so)
wrapper.java.library.path.1=lib

# Java Additional Parameters
#wrapper.java.additional.1=
wrapper.java.additional.1=-DMYCAT_HOME=.
wrapper.java.additional.2=-server
wrapper.java.additional.3=-XX:MaxPermSize=64M
wrapper.java.additional.4=-XX:+AggressiveOpts
wrapper.java.additional.5=-XX:MaxDirectMemorySize=2G
wrapper.java.additional.6=-Dcom.sun.management.jmxremote
wrapper.java.additional.7=-Dcom.sun.management.jmxremote.port=1984
wrapper.java.additional.8=-Dcom.sun.management.jmxremote.authenticate=false
wrapper.java.additional.9=-Dcom.sun.management.jmxremote.ssl=false
wrapper.java.additional.10=-Xmx4G
wrapper.java.additional.11=-Xms1G

# Initial Java Heap Size (in MB)
#wrapper.java.initmemory=3

# Maximum Java Heap Size (in MB)
#wrapper.java.maxmemory=64

# Application parameters.  Add parameters as needed starting from 1
wrapper.app.parameter.1=io.mycat.MycatStartup
wrapper.app.parameter.2=start

#********************************************************************
# Wrapper Logging Properties
#********************************************************************
# Format of output for the console.  (See docs for formats)
wrapper.console.format=PM

# Log Level for console output.  (See docs for log levels)
wrapper.console.loglevel=INFO

# Log file to use for wrapper output logging.
wrapper.logfile=logs/wrapper.log

# Format of output for the log file.  (See docs for formats)
wrapper.logfile.format=LPTM

# Log Level for log file output.  (See docs for log levels)
wrapper.logfile.loglevel=INFO

# Maximum size that the log file will be allowed to grow to before
#  the log is rolled. Size is specified in bytes.  The default value
#  of 0, disables log rolling.  May abbreviate with the 'k' (kb) or
#  'm' (mb) suffix.  For example: 10m = 10 megabytes.
wrapper.logfile.maxsize=0

# Maximum number of rolled log files which will be allowed before old
#  files are deleted.  The default value of 0 implies no limit.
wrapper.logfile.maxfiles=0

# Log Level for sys/event log output.  (See docs for log levels)
wrapper.syslog.loglevel=NONE

#********************************************************************
# Wrapper Windows Properties
#********************************************************************
# Title to use when running as a console
wrapper.console.title=Mycat-server

#********************************************************************
# Wrapper Windows NT/2000/XP Service Properties
#********************************************************************
# WARNING - Do not modify any of these properties when an application
#  using this configuration file has been installed as a service.
#  Please uninstall the service before modifying this section.  The
#  service can then be reinstalled.

# Name of the service
wrapper.ntservice.name=mycat

# Display name of the service
wrapper.ntservice.displayname=Mycat-server

# Description of the service
wrapper.ntservice.description=The project of Mycat-server

# Service dependencies.  Add dependencies as needed starting from 1
wrapper.ntservice.dependency.1=

# Mode in which the service is installed.  AUTO_START or DEMAND_START
wrapper.ntservice.starttype=AUTO_START

# Allow the service to interact with the desktop.
wrapper.ntservice.interactive=false

wrapper.ping.timeout=120
configuration.directory.in.classpath.first=conf

5.修改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="defaultSqlParser">druidparser</property>
    <property name="useSqlStat"></property>  <!-- 1为开启实时统计、0为关闭 -->
    <property name="useGlobleTableCheck"></property>  <!-- 1为开启全加班一致性检测、0为关闭 -->

        <property name="sequnceHandlerType"></property>
      <!--  <property name="useCompression"></property>--> <!--1为开启mysql压缩协议-->
        <!--  <property name="fakeMySQLVersion">5.6.</property>--> <!--设置模拟的MySQL版本号-->
    <!-- <property name="processorBufferChunk"></property> -->
    <!--
    <property name="processors"></property>
    <property name="processorExecutor"></property>
     -->
        <!--默认为type : DirectByteBufferPool | type  ByteBufferArena-->
        <property name="processorBufferPoolType"></property>
        <!--默认是65535 64K 用于sql解析时最大文本长度 -->
        <!--<property name="maxStringLiteralLength"></property>-->
        <!--<property name="sequnceHandlerType"></property>-->
        <!--<property name="backSocketNoDelay"></property>-->
        <!--<property name="frontSocketNoDelay"></property>-->
        <!--<property name="processorExecutor"></property>-->
        <!--
            <property name="serverPort"></property> <property name="managerPort"></property>
            <property name="idleTimeout"></property> <property name="bindIp">0.0.0.0</property>
            <property name="frontWriteQueueSize"></property> <property name="processors"></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"></property>

            <!--
            off heap for merge/order/group/limit      1开启   0关闭
        -->
        <property name="useOffHeapForMerge"></property>

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

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

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

    <user name="test1">
        <property name="password"></property>
        <property name="schemas">TESTDB</property>

        <!-- 表级 DML 权限设置 -->
        <!--
        <privileges check="false">
            <schema name="TESTDB" dml="" >
                <table name="tb01" dml=""></table>
                <table name="tb02" dml=""></table>
            </schema>
        </privileges>
         -->
    </user>

    <user name="test2">
        <property name="password">user</property>
        <property name="schemas">TESTDB</property>
        <property name="readOnly">true</property>
    </user>

</mycat:server>

6.修改schema.xml

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

     <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="">
             <table name="g_user" primaryKey="user_id"  dataNode="Server1,Server2"  rule="sharding-by-mod" />

    </schema>

     <dataNode name="Server1" dataHost="172.16.130.189" database="mycattest" />
     <dataNode name="Server2" dataHost="172.16.130.190" database="mycattest" />

         <!-- data host definition for oe -->
   <dataHost name="172.16.130.189" maxCon="" minCon="" balance=""
        writeType="" dbType="mysql" dbDriver="native" switchType="-1"  slaveThreshold="">
        <heartbeat>select user()</heartbeat>
        <!-- can have multi write hosts -->
        <writeHost host="Server1" url="172.16.130.189:3306" user="mycattest" password="">
            <!-- can have multi read hosts -->
            <readHost host="Server3" url="172.16.130.191:3306" user="mycattest" password=""/>
        </writeHost>
    </dataHost>
    <dataHost name="172.16.130.190" maxCon="" minCon="" balance=""
        writeType="" dbType="mysql" dbDriver="native" switchType="-1"  slaveThreshold="">
        <heartbeat>select user()</heartbeat>
        <!-- can have multi write hosts -->
        <writeHost host="Server2" url="172.16.130.190:3306" user="mycattest" password="" >
            <!-- can have multi read hosts -->
            <readHost host="Server4" url="172.16.130.192:3306" user="mycattest" password=""/>
        </writeHost>
        <!-- <writeHost host="hostM2" url="localhost:3316" user="root" password=""/> -->
    </dataHost>

</mycat:schema>

7.启动Mycat

bogon:bin Randy$ ./mycat console
Running Mycat-server...
wrapper  | --> Wrapper Started as Console
wrapper  | Launching a JVM...
jvm     | Wrapper (Version 3.2.) http://wrapper.tanukisoftware.org
jvm     |   Copyright - Tanuki Software, Inc.  All Rights Reserved.
jvm     |
jvm     | -- ::, [INFO ][WrapperSimpleAppMain] total resouces of dataHost 172.16.130.190 is :  (io.mycat.backend.datasource.PhysicalDBPool:PhysicalDBPool.java:)
jvm     | -- ::, [INFO ][WrapperSimpleAppMain] total resouces of dataHost 172.16.130.189 is :  (io.mycat.backend.datasource.PhysicalDBPool:PhysicalDBPool.java:)
jvm     | -- ::, [INFO ][WrapperSimpleAppMain] create layer cache pool TableID2DataNodeCache of type encache ,default cache size  ,default expire seconds18000  (io.mycat.cache.CacheService:CacheService.java:)
jvm     | -- ::, [INFO ][WrapperSimpleAppMain] create child Cache: TESTDB_ORDERS for layered cache TableID2DataNodeCache, size , expire seconds   (io.mycat.cache.DefaultLayedCachePool:DefaultLayedCachePool.java:)
jvm     | -- ::, [DEBUG][WrapperSimpleAppMain] Configuring ehcache from ehcache.xml found in the classpath: file:/Users/Randy/Developer/16InstallSoftware/mycat/conf/ehcache.xml  (net.sf.ehcache.config.ConfigurationFactory:ConfigurationFactory.java:) 

******测试：

由于我在上面的配置中，定了表g_user按照sharding-by-mod算法规则来分片，

<table name="g_user" primaryKey="user_id"  dataNode="Server1,Server2"  rule="sharding-by-mod" />

通过Mycat插入了两条数据

insert into g_user(id) values(1);
insert into g_user(id) values(2);

通过查询，发现id=1的数据被插入到了M2和S2数据库服务器，而id=2的数据被插入到了M1和S1数据库