前言：
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
......
关于mycat更多的介绍，及文档，请点击Mycat官网
准备工作：
1、安装JDK：参考
2、安装Mycat：参考
3、配置数据库的主从同步：参考
开始搬砖：
1.配置/conf/schema.xml
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
<!-- 配置逻辑库XMDB -->
<schema name="XMDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1" />
<!-- 映射到你实际数据库中的库名：xm -->
<dataNode name="dn1" dataHost="node1" database="xm"/>
<!-- 配置Host，设置数据库的参数 -->
<dataHost name="node1" maxCon="1000" minCon="10" balance="1" dbType="mysql" dbDriver="native">
<!-- 心跳检测,来看下面的host是否还可用 -->
<heartbeat>select user()</heartbeat>
<!-- 读写分离 -->
<writeHost host="192.168.40.3" url="192.168.40.3:3306" user="root" password="123456">
<readHost host="192.168.40.3" url="192.168.40.3:3316" user="root" password="123456" />
</writeHost>
<writeHost host="192.168.40.3" url="192.168.40.3:3316" 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>
2.配置/conf/server.xml
1 <?xml version="1.0" encoding="UTF-8"?>
2 <!-- - - Licensed under the Apache License, Version 2.0 (the "License");
3 - you may not use this file except in compliance with the License. - You
4 may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0
5 - - Unless required by applicable law or agreed to in writing, software -
6 distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT
7 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the
8 License for the specific language governing permissions and - limitations
9 under the License. -->
10 <!DOCTYPE mycat:server SYSTEM "server.dtd">
11 <mycat:server xmlns:mycat="http://io.mycat/">
12 <system>
13 <property name="useSqlStat">0</property> <!-- 1为开启实时统计、0为关闭 -->
14 <property name="useGlobleTableCheck">0</property> <!-- 1为开启全加班一致性检测、0为关闭 -->
15
16 <property name="sequnceHandlerType">2</property>
17 <!-- <property name="useCompression">1</property>--> <!--1为开启mysql压缩协议-->
18 <!-- <property name="fakeMySQLVersion">5.6.20</property>--> <!--设置模拟的MySQL版本号-->
19 <!-- <property name="processorBufferChunk">40960</property> -->
20 <!--
21 <property name="processors">1</property>
22 <property name="processorExecutor">32</property>
23 -->
24 <!--默认为type 0: DirectByteBufferPool | type 1 ByteBufferArena-->
25 <property name="processorBufferPoolType">0</property>
26 <!--默认是65535 64K 用于sql解析时最大文本长度 -->
27 <!--<property name="maxStringLiteralLength">65535</property>-->
28 <!--<property name="sequnceHandlerType">0</property>-->
29 <!--<property name="backSocketNoDelay">1</property>-->
30 <!--<property name="frontSocketNoDelay">1</property>-->
31 <!--<property name="processorExecutor">16</property>-->
32 <!--
33 <property name="serverPort">8066</property> <property name="managerPort">9066</property>
34 <property name="idleTimeout">300000</property> <property name="bindIp">0.0.0.0</property>
35 <property name="frontWriteQueueSize">4096</property> <property name="processors">32</property> -->
36 <!--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-->
37 <property name="handleDistributedTransactions">0</property>
38
39 <!--
40 off heap for merge/order/group/limit 1开启 0关闭
41 -->
42 <property name="useOffHeapForMerge">1</property>
43
44 <!--
45 单位为m
46 -->
47 <property name="memoryPageSize">1m</property>
48
49 <!--
50 单位为k
51 -->
52 <property name="spillsFileBufferSize">1k</property>
53
54 <property name="useStreamOutput">0</property>
55
56 <!--
57 单位为m
58 -->
59 <property name="systemReserveMemorySize">384m</property>
60
61
62 <!--是否采用zookeeper协调切换 -->
63 <property name="useZKSwitch">true</property>
64
65
66 </system>
67
68 <!-- 全局SQL防火墙设置 -->
69 <!--
70 <firewall>
71 <whitehost>
72 <host host="127.0.0.1" user="mycat"/>
73 <host host="127.0.0.2" user="mycat"/>
74 </whitehost>
75 <blacklist check="false">
76 </blacklist>
77 </firewall>
78 -->
79
80 <!-- 配置用户 -->
81
82 <user name="root">
83 <property name="password">123456</property>
84 <property name="schemas">XMDB</property>
85
86 <!-- 表级 DML 权限设置 -->
87 <!--
88 <privileges check="false">
89 <schema name="TESTDB" dml="0110" >
90 <table name="tb01" dml="0000"></table>
91 <table name="tb02" dml="1111"></table>
92 </schema>
93 </privileges>
94 -->
95 </user>
96
97 <user name="user">
98 <property name="password">user</property>
99 <property name="schemas">XMDB</property>
100 <property name="readOnly">true</property>
101 </user>
102
103 </mycat:server>
3.开启mycat服务
：mycat start
4.查看开启状况/logs/wrapper.log
日志里会描述开启状况，及异常错误。
开启成功。
5.连接客户端测试读写分离。
