mycat的入门教程（一）

一、什么是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

二、 MyCat是一个基于cobar兴起的开源数据库中间件系统，当前深受广大开源爱好者的追捧以及DBA粉丝们的广泛研究。主要是面对解决高并发，高负载，海量存储等屏颈。

两张表users和test，两个数据库test,dmeo（两个库在一个数据库实例上） users在test中存储。 test在dmeo中存储。

-- ---------------------------- -- Table structure for `users` -- ---------------------------- DROP TABLE IF EXISTS `users`; CREATE TABLE `users` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `user_name` varchar(100) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; DROP TABLE IF EXISTS `test`; CREATE TABLE `test` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `name` varchar(50) NOT NULL, `phone` varchar(11) DEFAULT NULL, `create_time` datetime NOT NULL, `update_time` datetime NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COMMENT='用户测试表';

开始使用( mycat官方网站上下载安装包，网址为mycat )

解压之后：

然后在conf目录下编辑service.xml，rule.xml，schema.xml、warpper.conf四个文件。 1、service.xml主要配置mycat服务的参数，比如端口号，myact用户名和密码使用的逻辑数据库等 2、rule.xml主要配置路由策略，主要有分片的片键，拆分的策略（取模还是按区间划分等） 3、schema.xml文件主要配置数据库的信息，例如逻辑数据库名称，物理上真实的数据源以及表和数据源之间的对应关系和路由策略等。 4、warpper 日志：mycat启动，停止，添加为服务等都会记录到此日志文件，如果系统环境配置错误或缺少配置时，导致 Mycat 无法启动，可以通过查看 warrpper.log 定位具体错误原因。warrpper.log可以删除，删除后会自动重新生成该日志 配置如下所示： 需要修改的配置文件

(1)**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="defaultSqlParser">druidparser</property> <property name="mutiNodeLimitType">1</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">root</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>

(2)rule.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:rule SYSTEM "rule.dtd"> <mycat:rule xmlns:mycat="http://io.mycat/"> <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="crc32slot"> <rule> <columns>id</columns> <algorithm>crc32slot</algorithm> </rule> </tableRule> <tableRule name="sharding-by-month"> <rule> <columns>create_time</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="io.mycat.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，也就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的整数值也就是节点索引为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 --> <!-- <property name="bucketMapPath">/etc/mycat/bucketMapPath</property> 用于测试时观察各物理节点与虚拟节点的分布情况，如果指定了这个属性，会把虚拟节点的murmur hash值与物理节点的映射按行输出到这个文件，没有默认值，如果不指定，就不会输出任何东西 --> </function> <function name="crc32slot" class="io.mycat.route.function.PartitionByCRC32PreSlot"> <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 --> </function> <function name="hash-int" class="io.mycat.route.function.PartitionByFileMap"> <property name="mapFile">partition-hash-int.txt</property> </function> <function name="rang-long" class="io.mycat.route.function.AutoPartitionByLong"> <property name="mapFile">autopartition-long.txt</property> </function> <function name="mod-long" class="io.mycat.route.function.PartitionByMod"> <!-- how many data nodes --> <property name="count">2</property> </function> <function name="func1" class="io.mycat.route.function.PartitionByLong"> <property name="partitionCount">8</property> <property name="partitionLength">128</property> </function> <function name="latestMonth" class="io.mycat.route.function.LatestMonthPartion"> <property name="splitOneDay">24</property> </function> <function name="partbymonth" class="io.mycat.route.function.PartitionByMonth"> <property name="dateFormat">yyyy-MM-dd</property> <property name="sBeginDate">2015-01-01</property> </function> <function name="rang-mod" class="io.mycat.route.function.PartitionByRangeMod"> <property name="mapFile">partition-range-mod.txt</property> </function> <function name="jump-consistent-hash" class="io.mycat.route.function.PartitionByJumpConsistentHash"> <property name="totalBuckets">3</property> </function> </mycat:rule>

(3)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="100"> <!-- auto sharding by id (long) <table name="travelrecord" dataNode="dn1,dn2,dn3" rule="auto-sharding-long" />--> <!-- global table is auto cloned to all defined data nodes ,so can join with any table whose sharding node is in the same data node --> <table name="test" primaryKey="ID" type="global" dataNode="dn1" /> <table name="users" primaryKey="ID" type="global" dataNode="dn2"/> <!-- <table name="oc_call" primaryKey="ID" dataNode="dn1$0-743" rule="latest-month-calldate" /> --> </schema> <!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743" /> --> <dataNode name="dn1" dataHost="localhost1" database="dmeo" /> <dataNode name="dn2" dataHost="localhost1" database="test" /> <!--<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> <!-- can have multi write hosts --> <writeHost host="hostM1" url="localhost:3306" user="root" password="root"> <!-- can have multi read hosts --> <readHost host="hostS2" url="127.0.0.1:3306" user="root" password="root" /> </writeHost> <!--<writeHost host="hostS1" url="localhost:3316" user="root" password="123456" /> <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>

（4）wrapper.conf

（5）环境变量配置

（6）在命令行切换到bin目录下，然后执行如下命令： （7）启动成功如下所示：

（8）使用Navicat for Mysql可视化工具连接数据如下：