其实mycat的核心就是3个配置文件，理解了之后就很简单了。一下配置就是按天分片，数据分布到3个机器，6个库里


有3个节点，每个节点上创建两个数据库 节点1  db1,db2 , 节点2 db3，db4,  节点3 ：db5,db6

6个库分别创建一个表：t1

t1表结构为：

create table t1 (
  id int(10) unsigned not null,
  k int(10) unsigned not null default '0',
  c char(120) not null default '',
  pad char(60) not null default '',
  primary key (id),
  key k_1 (k)
) engine=innodb default charset=utf8


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="t1" primaryKey="id" dataNode="dn01,dn02,dn03,dn04,dn05,dn06" rule="mod-long" />
        </schema>

      <dataNode name="dn01" dataHost="node1" database="db1" />
        <dataNode name="dn02" dataHost="node2" database="db2" />    

    <dataNode name="dn03" dataHost="node3" database="db3" />
        <dataNode name="dn04" dataHost="node4" database="db4" />

    <dataNode name="dn05" dataHost="node5" database="db5" />
        <dataNode name="dn06" dataHost="node6" database="db6" />

    <dataHost name="node1" maxCon="2000" minCon="10" balance="0"
              writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
        <heartbeat>select user()</heartbeat>
        <writeHost host="hostM1" url="56.56.56.201:3306" user="my" password="123456"></writeHost>
    </dataHost>

        <dataHost name="node2" maxCon="2000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="hostM1" url="56.56.56.201:3306" user="my" password="123456"></writeHost>
        </dataHost>

        <dataHost name="node3" maxCon="2000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="hostM2" url="56.56.56.204:3306" user="my" password="123456"></writeHost>
        </dataHost>

        <dataHost name="node4" maxCon="2000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="hostM2" url="56.56.56.204:3306" user="my" password="123456"></writeHost>
        </dataHost>

        <dataHost name="node5" maxCon="2000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="hostM3" url="56.56.56.206:3306" user="my" password="123456"></writeHost>
        </dataHost>
        <dataHost name="node6" maxCon="2000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="hostM3" url="56.56.56.206:3306" user="my" password="123456"></writeHost>
        </dataHost>

</mycat:schema>


rule.xml

<function name="mod-long" class="io.mycat.route.function.PartitionByMod">
                <!-- how many data nodes -->
                <property name="count">6</property>
</function>
MySQL [(none)]> use testdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MySQL [testdb]> show tables;
+------------------+
| Tables in testdb |
+------------------+
| t1               |
+------------------+
1 row in set (0.01 sec)

MySQL [testdb]> desc t1;
+-------+------------------+------+-----+---------+-------+
| Field | Type             | Null | Key | Default | Extra |
+-------+------------------+------+-----+---------+-------+
| id    | int(10) unsigned | NO   | PRI | NULL    |       |
| k     | int(10) unsigned | NO   | MUL | 0       |       |
| c     | char(120)        | NO   |     |         |       |
| pad   | char(60)         | NO   |     |         |       |
+-------+------------------+------+-----+---------+-------+
4 rows in set (0.01 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(1,100,'aaa','aaa');
Query OK, 1 row affected (0.05 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(2,100,'aaa','aaa');
Query OK, 1 row affected (0.00 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(3,100,'aaa','aaa');
Query OK, 1 row affected (0.00 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(4,100,'aaa','aaa');
Query OK, 1 row affected (0.01 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(5,100,'aaa','aaa');
Query OK, 1 row affected (0.00 sec)

MySQL [testdb]> insert into t1(id,k,c,pad) values(6,100,'aaa','aaa');
Query OK, 1 row affected (0.00 sec)

root@localhost :db202:55:50>select * from t1;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    90
Current database: db2

+----+-----+-----+-----+
| id | k  | c  | pad |
+----+-----+-----+-----+
|  1 | 100 | aaa | aaa |
+----+-----+-----+-----+
1 row in set (0.00 sec)

root@localhost :db203:20:01>use db1;
Database changed
root@localhost :db103:20:05>select * from t1;
+----+-----+-----+-----+
| id | k  | c  | pad |
+----+-----+-----+-----+
|  6 | 100 | aaa | aaa |
+----+-----+-----+-----+
1 row in set (0.00 sec)



插入了6条数据，可以看到每个数据库，表里面只有1条数据。