下载地址MYCAT官方网站 jdk安装配置 首先去oracle官网下载并安装jdk8,添加环境变量,JAVA_HOME设置为D:WorksoftwareJavajdk1.8 CLASSPATH设置为.;%JAVA_HOME%lib;%JAVA_HOME%lib ools.jar path系统变量追加%JAVA_HOME%in; Mycat安装配置
  首先添加Windows环境变量,MYCAT_HOME设置为安装目录E:WorkSoftWareMycatServer1.5
  为了降低资源占用,mycat的jvm设置在startup_nowrap.bat,打开后可以清楚看到如下配置:
  “%JAVA_CMD%” -server -Xms1G -Xmx2G -XX:MaxPermSize=64M -XX:+AggressiveOpts -XX:MaxDirectMemorySize=1G -DMYCAT_HOME=%MYCAT_HOME% -cp “..conf;..lib*” io.mycat.MycatStartup
  这里将-Xms1G改成-Xms512M,-Xmx2G改成-Xmx1024M,保存后重新启动即可.
  wrapper.conf文件里的改成wrapper.java.command=E:WorkSoftWarejdk1.8injava.exe Mycat启动的配置 schema.xml配置文件,如果分库在不同的服务器,可以配置两个datahost;如果在一个datahost中配置多个writeHost,则为主从配置。type=”global”时,为全局表
  <?xml version="1.0"?>
  <!DOCTYPE mycat:schema SYSTEM "schema.dtd">
  <mycat:schema xmlns:mycat="http://org.opencloudb/" >
  <!--在这一行参数里面,schema name定义了可以在MyCAT前端显示的逻辑数据库的名字,checkSQLschema这个参数为False的时候,表明MyCAT会自动忽略掉表名前的数据库名,比如说mydatabase1.test1,会被当做test1;sqlMaxLimit指定了SQL语句返回的行数限制-->
  <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100">
  <!-- 主键范围规则 -->
  <!-- 这一行代表在MyCAT前端会显示哪些表名,类似几行都代表一样的意思,这里强调的是表,而MyCAT并不会在配置文件里面定义表结构,如果在前端使用show create table ,MyCAT会显示正常的表结构信息,观察Debug日志,可以看到,MyCAT把命令分发给了dn1代表的数据库,然后把dn1的查询结果返回给了前端 可以判断,类似的数据库级别的一些查询指令,有可能是单独分发给某个节点,然后再把某个节点的信息返回给前端。
  dataNode的意义很简单,这个逻辑表的数据存储在后端的哪几个数据库里面rule代表的是这个逻辑表students的具体切分策略,目前MyCAT只支持按照某一个特殊列,遵循一些特殊的规则来切分,如取模,枚举等,具体的留给之后细说                 
  -->
  <table name="travelrecord" dataNode="dn1,dn2,dn3" rule="auto-sharding-long" />
  <table name="company" primaryKey="ID" dataNode="dn3,dn2,dn1" rule="mod-long"/>
  <table name="goods" primaryKey="ID" type="global" dataNode="dn1,dn2" />
  <!--求模分片随机规则 -->
  <table name="hotnews" primaryKey="ID" dataNode="dn1,dn2,dn3"
  rule="mod-long" />
  <table name="employee" primaryKey="ID" dataNode="dn1,dn2"
  rule="sharding-by-intfile" />
  <table name="customer" primaryKey="ID" dataNode="dn1,dn2"
  rule="sharding-by-intfile">
  <!--
  childtable我在测试中并没有实际用起来不过在MyCAT的设计文档里面有提到,childtable是一种依赖于父表的结构,
  这意味着,childtable的joinkey会按照父表的parentKey的策略一起切分,当父表与子表进行连接,
  且连接条件是childtable.joinKey=parenttable.parentKey时,不会进行跨库的连接.
  -->
  <childTable name="orders" primaryKey="ID" joinKey="customer_id"
  parentKey="id">
  <childTable name="order_items" joinKey="order_id"
  parentKey="id" />
  </childTable>
  <childTable name="customer_addr" primaryKey="ID" joinKey="customer_id"
  parentKey="id" />
  </table>
  <!-- 全局表是自动克隆到所有定义的数据节点,这样可以与拆分节点的任何表连接查询,是在同一个数据节点-->
  <table name="news_table" primaryKey="ID" type="global" dataNode="dn1,dn2,dn3" />
  </schema>
  <dataNode name="dn1" dataHost="localhost1" database="mycatDB1" />
  <dataNode name="dn2" dataHost="localhost1" database="mycatDB2" />
  <dataNode name="dn3" dataHost="localhost1" database="mycatDB3" />
  <!--
  dataHost配置的是实际的后端数据库集群,大部分参数简单易懂,这里不一个个介绍了,只介绍比较重要的两个参数,writeType和balance.
  -->
  <!-- writeType和balance是用来控制后端集群的读写分离的关键参数,这里我用了双主双从的集群配置
  这里的测试过程比较麻烦,所以直接贴结论:
  1.balance=0时,读操作都在localhost上(localhost失败时,后端直接失败)
  2.balance=1时,读操作会随机分散在localhost1和两个readhost上面(localhost失败时,写操作会在localhost1,如果localhost1再失败,则无法进行写操作)
  3.balance=2时,写操作会在localhost上,读操作会随机分散在localhost1,localhost1和两个readhost上面(同上)
  4.writeType=0时,写操作会在localhost上,如果localhost失败,会自动切换到localhost1,localhost恢复以后并不会切换回localhost进行写操作
  5.writeType=1时,写操作会随机分布在localhost和localhost1上,单点失败并不会影响集群的写操作,但是后端的从库会无法从挂掉的主库获取更新,会在读数据的时候出现数据不一致
  举例:localhost失败了,写操作会在localhost1上面进行,localhost1的主从正常运行,但是localhost的从库无法从localhost获取更新,localhost的从库于其他库出现数据不一致
  -->
  <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="localhost:3306" user="root"
  password="123456">
  <!-- can have multi read hosts -->
  <!--<readHost host="hostS2" url="192.168.1.200:3306" user="root" password="xxx" />-->
  </writeHost>
  </dataHost>
  </mycat:schema>
  server.xml配置文件
  <?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://org.opencloudb/">
  <system>
  <property name="defaultSqlParser">druidparser</property>
  <!--  <property name="useCompression">1</property>--> <!--1为开启mysql压缩协议-->
  <!-- <property name="processorBufferChunk">40960</property> -->
  <!--
  <property name="processors">1</property>
  <property name="processorExecutor">32</property>
  -->
  <!--默认是65535 64K 用于sql解析时大文本长度 -->
  <!--<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="mutiNodeLimitType">1</property> 0:开启小数量级(默认) ;1:开启亿级数据排序
  <property name="mutiNodePatchSize">100</property> 亿级数量排序批量
  <property name="processors">32</property> <property name="processorExecutor">32</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> -->
  </system>
  <user name="test"><!--用户名-->
  <property name="password">test</property><!--密码-->
  <!--实例名,和schema.xml定义的schema对应,这里的实例名是虚拟名,也是对mycat服务的一种别名,是应用程序以及客户端连接的入口。-->
  <property name="schemas">TESTDB</property>
  </user>
  <user name="user">
  <property name="password">user</property>
  <property name="schemas">TESTDB</property>
  <property name="readOnly">true</property>
  </user>
  <!--
  <quarantine>
  <whitehost>
  <host host="127.0.0.1" user="mycat"/>
  <host host="127.0.0.2" user="mycat"/>
  </whitehost>
  <blacklist check="false"></blacklist>
  </quarantine>
  -->
  </mycat:server>
  rule.xml配置文件
  <?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:rule SYSTEM "rule.dtd">
  <mycat:rule xmlns:mycat="http://org.opencloudb/">
  <tableRule name="rule1">
  <rule>
  <columns>id</columns>
  <algorithm>func1</algorithm>
  </rule>
  </tableRule>
  <tableRule name="rule2">
  <rule>
  <columns>user_id</columns>
  <algorithm>func1</algorithm>
  </rule>
  </tableRule>
  <tableRule name="sharding-by-intfile">
  <rule>
  <columns>sharding_id</columns>
  <algorithm>hash-int</algorithm>
  </rule>
  </tableRule>
  <tableRule name="auto-sharding-long">
  <rule>
  <columns>id</columns>
  <algorithm>rang-long</algorithm>
  </rule>
  </tableRule>
  <tableRule name="mod-long">
  <rule>
  <columns>id</columns>
  <algorithm>mod-long</algorithm>
  </rule>
  </tableRule>
  <tableRule name="sharding-by-murmur">
  <rule>
  <columns>id</columns>
  <algorithm>murmur</algorithm>
  </rule>
  </tableRule>
  <tableRule name="sharding-by-month">
  <rule>
  <columns>create_date</columns>
  <algorithm>partbymonth</algorithm>
  </rule>
  </tableRule>
  <tableRule name="latest-month-calldate">
  <rule>
  <columns>calldate</columns>
  <algorithm>latestMonth</algorithm>
  </rule>
  </tableRule>
  <tableRule name="auto-sharding-rang-mod">
  <rule>
  <columns>id</columns>
  <algorithm>rang-mod</algorithm>
  </rule>
  </tableRule>
  <tableRule name="jch">
  <rule>
  <columns>id</columns>
  <algorithm>jump-consistent-hash</algorithm>
  </rule>
  </tableRule>
  <function name="murmur"
  class="org.opencloudb.route.function.PartitionByMurmurHash">
  <property name="seed">0</property><!-- 默认是0 -->
  <property name="count">2</property><!-- 要分片的数据库节点数量,必须指定,否则没法分片 -->
  <property name="virtualBucketTimes">160</property><!-- 一个实际的数据库节点被映射为这么多虚拟节点,默认是160倍,也是虚拟节点数是物理节点数的160倍 -->
  <!-- <property name="weightMapFile">weightMapFile</property> 节点的权重,没有指定权重的节点默认是1。以properties文件的格式填写,以从0开始到count-1的整数值也是节点索引为key,以节点权重值为值。所有权重值必须是正整数,否则以1代替 -->