MyCat分片

需求

把一张表分片存储到三个数据库中

环境

• Mysql节点环境
  • 操作系统版本 : Centos7
  • 数据库版本 : Mysql-5.6
  • 数据库名 : db1、db2、db3
  • ip:192.168.188.99
• MyCat节点
  • mycat版本 ：1.6 release
  • ip:192.168.188.100

安装MyCat到节点上

MyCat需要有JDK环境的支持所以在运行Mycat之前需要安装JDK.

MyCat官方网站下载1.6版本的Mycat到节点上,

配置Mycat

配置schema.xml

Schema.xml介绍

Schema.xml作为MyCat中重要的配置文件之一，管理着MyCat的**逻辑库、表、**分片规则、DataNode以及DataSource。

• schema 标签用于定义MyCat实例中的逻辑库
• Table 标签定义了MyCat中的逻辑表
• dataNode 标签定义了MyCat中的数据节点，也就是我们通常说所的数据分片。
• dataHost标签在mycat逻辑库中也是作为最底层的标签存在，直接定义了具体的数据库实例、读写分离配置和心跳语句。

Schema.xml文件位置

mycat1.6/mycat/conf
           

我的Schema.xml文件详细信息

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

	<schema name="TESTDB" checkSQLschema="true" sqlMaxLimit="100">
		<!-- auto sharding by id (long) -->
		<table name="item" dataNode="dn1,dn2,dn3" rule="mod-long" />

	</schema>
	<!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743"
		/> -->
	<dataNode name="dn1" dataHost="localhost1" database="db1" />
	<dataNode name="dn2" dataHost="localhost1" database="db2" />
	<dataNode name="dn3" dataHost="localhost1" database="db3" />
	<!--<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>
		<!--这里配置的是我们Mysql服务器信息,ip端口号,账号,密码-->
		<writeHost host="hostM1" url="192.168.188.99:3306" user="root"
				   password="xiao123." />
		<!-- <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>
           

server.xml

server.xml保存mycat需要的系统配置信息。最常用的是配置用户名、密码及权限

<?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>
	-->
	
	<user name="root">
		<property name="password">123456</property>
		<property name="schemas">TESTDB</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">TESTDB</property>
		<property name="readOnly">true</property>
	</user>

</mycat:server>
           

配置rule.xml

rule.xml定义了我们对表进行拆分所涉及到的规则定义。我们可以灵活的对表使用不同的分片算法，或者对表使用相同的算法但具体的参数不同.

无需配置,默认就好

测试分片

启动Mycat

在mycat的bin目录下执行命令

./mycat start
           

通过查看日志Mycat的日志文件查看Mycat是否启动成功

日志文件位置

mycat/logs/mycat.log
mycat/logs/wrapper.log
           

这里贴上我的mycat.log文件内容

2019-08-20 23:34:31.422  INFO [WrapperSimpleAppMain] (io.mycat.backend.datasource.PhysicalDBPool.<init>(PhysicalDBPool.java:100)) - total resouces of dataHost localhost1 is :1
2019-08-20 23:34:32.097  INFO [WrapperSimpleAppMain] (io.mycat.cache.CacheService.createLayeredPool(CacheService.java:125)) - create layer cache pool TableID2DataNodeCache of type encache ,default cache size 10000 ,default expire seconds18000
2019-08-20 23:34:32.113  INFO [WrapperSimpleAppMain] (io.mycat.cache.DefaultLayedCachePool.createChildCache(DefaultLayedCachePool.java:80)) - create child Cache: TESTDB_ORDERS for layered cache TableID2DataNodeCache, size 50000, expire seconds 18000
2019-08-20 23:34:33.482  INFO [WrapperSimpleAppMain] (io.mycat.config.classloader.DynaClassLoader.<init>(DynaClassLoader.java:34)) - dyna class load from ./catlet,and auto check for class file modified every 60 seconds
2019-08-20 23:34:33.483  INFO [WrapperSimpleAppMain] (io.mycat.MycatServer.startup(MycatServer.java:266)) - ===============================================
2019-08-20 23:34:33.483  INFO [WrapperSimpleAppMain] (io.mycat.MycatServer.startup(MycatServer.java:267)) - MyCat is ready to startup ...
2019-08-20 23:34:33.483  INFO [WrapperSimpleAppMain] (io.mycat.MycatServer.startup(MycatServer.java:279)) - Startup processors ...,total processors:1,aio thread pool size:4    
 each process allocated socket buffer pool  bytes ,a page size:2097152  a page's chunk number(PageSize/ChunkSize) is:512  buffer page's number is:20
2019-08-20 23:34:33.483  INFO [WrapperSimpleAppMain] (io.mycat.MycatServer.startup(MycatServer.java:280)) - sysconfig params:SystemConfig [processorBufferLocalPercent=100, frontSocketSoRcvbuf=1048576, frontSocketSoSndbuf=4194304, backSocketSoRcvbuf=4194304, backSocketSoSndbuf=1048576, frontSocketNoDelay=1, backSocketNoDelay=1, maxStringLiteralLength=65535, frontWriteQueueSize=2048, bindIp=0.0.0.0, serverPort=8066, managerPort=9066, charset=utf8, processors=1, processorExecutor=4, timerExecutor=2, managerExecutor=2, idleTimeout=1800000, catletClassCheckSeconds=60, sqlExecuteTimeout=300, processorCheckPeriod=1000, dataNodeIdleCheckPeriod=300000, dataNodeHeartbeatPeriod=10000, clusterHeartbeatUser=_HEARTBEAT_USER_, clusterHeartbeatPass=_HEARTBEAT_PASS_, clusterHeartbeatPeriod=5000, clusterHeartbeatTimeout=10000, clusterHeartbeatRetry=10, txIsolation=3, parserCommentVersion=50148, sqlRecordCount=10, bufferPoolPageSize=2097152, bufferPoolChunkSize=4096, bufferPoolPageNumber=20, maxResultSet=524288, bigResultSizeSqlCount=10, bufferUsagePercent=80, flowControlRejectStrategy=0, clearBigSqLResultSetMapMs=600000, defaultMaxLimit=100, sequnceHandlerType=2, sqlInterceptor=io.mycat.server.interceptor.impl.DefaultSqlInterceptor, sqlInterceptorType=select, sqlInterceptorFile=/root/mycat1.6/mycat/logs/sql.txt, mutiNodeLimitType=0, mutiNodePatchSize=100, defaultSqlParser=druidparser, usingAIO=0, packetHeaderSize=4, maxPacketSize=16777216, mycatNodeId=1]
           

创建数据表

在Mysql服务器上根据schema.xml的配置创建三个数据库,分别是db1,db2,db3,然后三个数据库中必须创建一样的表item.

create table item(int id,int age);
           

使用Mysql客户端连接Mycat

配置完毕以及在Mysql服务器上创建完数据库之后，重新启动mycat。使用mysql客户端连接mycat

• -u:Mycat用户名(默认root)
• -p:Mycat密码(默认123465)
• -h:Mycat机IP地址
• -P:Mycat端口(默认8066)

插入数据进行测试

在连接上数据库之后Mycat会在TESTDB数据库中自动生成一张item表.

在Mycat客户端插入数据

这里我们在Mycat客户端插入了6条数据,那么这6条数据会怎么分配呢?会全部分配到db1呢还是?

结果是每个库中两个.