mycat 连续分片 -> 按日期（天）分片

1，按日期（天）分片

按日期（天）分片：从开始日期算起，按照天数来分片

例如，从2016-01-01，每10天一个分片

注意事项：需要提前将分片规划好，建好，否则有可能日期超出实际配置分片数

2，添加配置文件

在function.xml里面进行配置：

    <function name="sharding-by-date" class="org.opencloudb.route.function.PartitionByDate">
        <property name="dateFormat">yyyy-MM-dd</property>      <!-—日期格式-->
        <property name="sBeginDate">2016-01-01</property>            <!--开始日期-->
        <property name="sPartionDay">10</property>  <!--每分片天数-->
    </function>      

        <tableRule name="sharding-by-date-tr04">
                 <rule>
                         <columns>CREATE_TIME</columns>
                         <algorithm>sharding-by-date</algorithm>
                </rule>
        </tableRule>

在schema.xml里面进行配置：

    <table name="ORDER0402" primaryKey="ID" dataNode="dn21,dn22" rule="sharding-by-date-tr04"/>

3，建表并且录入数据

    CREATE TABLE ORDER0402(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME);
    mysql> CREATE TABLE ORDER0402(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME);
    Query OK, 0 rows affected (0.05 sec)

    mysql>
    INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,‘shanghai‘,‘shanghai10006_2016-01-03‘,‘2016-01-03‘);
    INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘);
    mysql> CREATE TABLE ORDER0402(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME);
    Query OK, 0 rows affected (0.06 sec)

    mysql> explain INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,‘shanghai‘,‘shanghai10006_2016-01-03‘,‘2016-01-03‘);
    +-----------+--------------------------------------------------------------------------------------------------------------------+
    | DATA_NODE | SQL                                                                                                                |
    +-----------+--------------------------------------------------------------------------------------------------------------------+
    | dn21      | INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,‘shanghai‘,‘shanghai10006_2016-01-03‘,‘2016-01-03‘) |
    +-----------+--------------------------------------------------------------------------------------------------------------------+
    1 row in set (0.11 sec)

    mysql> INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,‘shanghai‘,‘shanghai10006_2016-01-03‘,‘2016-01-03‘);
    Query OK, 1 row affected (0.00 sec)

    mysql>
    mysql> explain INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘);
    +-----------+----------------------------------------------------------------------------------------------------------------------+
    | DATA_NODE | SQL                                                                                                                  |
    +-----------+----------------------------------------------------------------------------------------------------------------------+
    | dn22      | INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘) |
    +-----------+----------------------------------------------------------------------------------------------------------------------+
    1 row in set (0.01 sec)

    mysql> INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘);
    Query OK, 1 row affected (0.01 sec)

    mysql> 

4，对insert操作流程进行分析，参考mycat.log对路由过程做完整的分析

查看后台mycat.log分析如下：

开始获取连接：
    02/12 22:23:26.386  DEBUG [$_NIOREACTOR-2-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=TESTDB, host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘)

开始路由匹配：
    02/12 22:23:26.388  DEBUG [$_NIOREACTOR-2-RW] (NonBlockingSession.java:113) -ServerConnection [id=1, schema=TESTDB, host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘), route={
       1 -> dn22{INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘)}

匹配好路由后，直接往对应的dn22节点开始执行insert数据录入操作：
    02/12 22:23:26.403  DEBUG [$_NIOREACTOR-1-RW] (NonBlockingSession.java:229) -release connection MySQLConnection [id=17, lastTime=1455287006372, user=root, schema=db3, old shema=db3, borrowed=true, fromSlaveDB=false, threadId=90, charset=latin1, txIsolation=3, autocommit=true, attachment=dn22{INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘)}, respHandler=SingleNodeHandler [node=dn22{INSERT INTO ORDER0402(ID,PROVINCE,SN,CREATE_TIME) VALUES(5000001,‘shanghai‘,‘shanghai10006_2016-01-13‘,‘2016-01-13‘)}, packetId=0], host=10.254.1.11, port=3327, statusSync=null, writeQueue=0, modifiedSQLExecuted=true]

操作完成，开始释放连接：
    02/12 22:23:26.404  DEBUG [$_NIOREACTOR-1-RW] (PhysicalDatasource.java:403) -release channel MySQLConnection [id=17, lastTime=1455287006372, user=root, schema=db3, old shema=db3, borrowed=true, fromSlaveDB=false, threadId=90, charset=latin1, txIsolation=3, autocommit=true, attachment=null, respHandler=null, host=10.254.1.11, port=3327, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]

5，执行简单的查询，如果指定分片字段ID字段，则走分片查询单个分片节点

mycat命令台显示结果：

    mysql>  explain select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘;
    +-----------+--------------------------------------------------------------------------+
    | DATA_NODE | SQL                                                                      |
    +-----------+--------------------------------------------------------------------------+
    | dn21      | SELECT * FROM ORDER0402 t1 WHERE t1.CREATE_TIME = ‘2016-01-03‘ LIMIT 100 |
    +-----------+--------------------------------------------------------------------------+
    1 row in set (0.04 sec)

    mysql> select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘;
    +-------+----------+--------------------------+---------------------+
    | ID    | PROVINCE | SN                       | CREATE_TIME         |
    +-------+----------+--------------------------+---------------------+
    | 10001 | shanghai | shanghai10006_2016-01-03 | 2016-01-03 00:00:00 |
    +-------+----------+--------------------------+---------------------+
    1 row in set (0.00 sec)

    mysql> 

查看后台mycat日志信息：

    02/12 22:44:13.773  DEBUG [$_NIOREACTOR-2-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=TESTDB, host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]explain select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘
    02/12 22:44:13.774  DEBUG [$_NIOREACTOR-2-RW] (EnchachePool.java:76) -SQLRouteCache  miss cache ,key:TESTDB select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘
    02/12 22:44:13.812  DEBUG [$_NIOREACTOR-2-RW] (EnchachePool.java:59) -SQLRouteCache add cache ,key:TESTDB select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘ value:select * from ORDER0402 t1 where t1.CREATE_TIME=‘2016-01-03‘, route={
       1 -> dn21{SELECT *
    FROM ORDER0402 t1
    WHERE t1.CREATE_TIME = ‘2016-01-03‘
    LIMIT 100}
    }

6，如果分片字段范围的查询，则走所有节点去检索，哪怕只有一条数据在一个分片上，route路由也是走所有的分片进行检索查询

    mysql> explain select * from ORDER0402 t1 where t1.CREATE_TIME<‘2016-01-04‘;
    +-----------+--------------------------------------------------------------------------+
    | DATA_NODE | SQL                                                                      |
    +-----------+--------------------------------------------------------------------------+
    | dn21      | SELECT * FROM ORDER0402 t1 WHERE t1.CREATE_TIME < ‘2016-01-04‘ LIMIT 100 |
    | dn22      | SELECT * FROM ORDER0402 t1 WHERE t1.CREATE_TIME < ‘2016-01-04‘ LIMIT 100 |
    +-----------+--------------------------------------------------------------------------+
    2 rows in set (0.01 sec)

    mysql> 

7，如果不走分片字段的查询，即使是单个数据，也要route路由所有的分片，走所有的分片进行查询

    mysql> explain select * from ORDER0402 t1 where t1.SN=‘shanghai10006_2016-01-03‘;
    +-----------+-------------------------------------------------------------------------------+
    | DATA_NODE | SQL                                                                           |
    +-----------+-------------------------------------------------------------------------------+
    | dn21      | SELECT * FROM ORDER0402 t1 WHERE t1.SN = ‘shanghai10006_2016-01-03‘ LIMIT 100 |
    | dn22      | SELECT * FROM ORDER0402 t1 WHERE t1.SN = ‘shanghai10006_2016-01-03‘ LIMIT 100 |
    +-----------+-------------------------------------------------------------------------------+
    2 rows in set (0.01 sec)

    mysql>