Mycat之——按日期(天)分片

转载请注明出处：http://blog.csdn.net/l1028386804/article/details/77018426

一、简单描述

这篇文章就给大家介绍如何用Mycat实现按日期(天)来进行数据分片操作，

即满足如下要求：
按日期（天）分片：从开始日期算起，按照天数来分片
例如，从2017-01-01，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

二、实现数据分片

1、配置rule.xml

在rule.xml中添加如下配置：

<tableRule name="sharding-by-date-customer">     <rule>         <columns>create_time</columns>         <algorithm>sharding-by-date</algorithm>    </rule></tableRule><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">2017-01-01</property>    <!--开始日期-->    <property name="sPartionDay">10</property>           <!--每分片天数--></function>   

2、配置schema.xml

<?xml version="1.0"?><!DOCTYPE mycat:schema SYSTEM "schema.dtd"><mycat:schema xmlns:mycat="http://org.opencloudb/" ><schema name="lyzdb" checkSQLschema="false" sqlMaxLimit="100"><!-- 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="t_order" primaryKey="id" dataNode="dn1,dn2" rule="sharding-by-date-customer"/></schema><!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743" /> --><dataNode name="dn1" dataHost="localhost1" database="db1" /><dataNode name="dn2" dataHost="localhost1" database="db2" /><!--<dataNode name="dn4" dataHost="sequoiadb1" database="SAMPLE" /> <dataNode name="jdbc_dn1" dataHost="jdbchost" database="db1" /> <dataNodename="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="192.168.209.137:3306" 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></mycat:schema>

至此，Mycat的配置工作就完成了，是不是很简单呢，下面我们就通过测试来分析一下Mycat的路由规则。

三、测试数据分片

1、建表并录入数据

首先，我们执行建表操作

mysql> explain  CREATE TABLE t_order (ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME);+-----------+----------------------------------------------------------------------------------------------------------------------------+| DATA_NODE | SQL                                                                                                                        |+-----------+----------------------------------------------------------------------------------------------------------------------------+| dn1       | CREATE TABLE t_order (ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME) || dn2       | CREATE TABLE t_order (ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME) |+-----------+----------------------------------------------------------------------------------------------------------------------------+2 rows in set (0.01 sec)mysql>mysql>mysql>  CREATE TABLE t_order (ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,PROVINCE VARCHAR(16),SN VARCHAR(64),CREATE_TIME DATETIME);Query OK, 0 rows affected (0.27 sec)

可以看出，建表SQL路由到了所有的数据节点上。

接下来我们执行数据录入操作

mysql> explain INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09');+-----------+-----------------------------------------------------------------------------------------------------------------+| DATA_NODE | SQL                                                                                                             |+-----------+-----------------------------------------------------------------------------------------------------------------+| dn1       | INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09') |+-----------+-----------------------------------------------------------------------------------------------------------------+1 row in set (0.05 sec)mysql> INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09');Query OK, 1 row affected (0.05 sec)mysql> explain INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11');+-----------+-----------------------------------------------------------------------------------------------------------------+| DATA_NODE | SQL                                                                                                             |+-----------+-----------------------------------------------------------------------------------------------------------------+| dn2       | INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11') |+-----------+-----------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)mysql>mysql> INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11');Query OK, 1 row affected (0.01 sec)

我们可以看出，日期为2017-01-09的数据SQL路由到了dn1节点，日期为2017-01-11的数据路由到了dn2节点，符合我们配置的Mycat路由规则。

2、录入数据的Mycat日志

我们打开Mycat的日志，观察如下：

08/09 23:23:03.272  DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]explain INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09')08/09 23:23:07.718  DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09')08/09 23:23:07.719  DEBUG [$_NIOREACTOR-0-RW] (NonBlockingSession.java:113) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09'), route={   1 -> dn1{INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(10001,'beijing','beijing10001_2017-01-09','2017-01-09')}} rrs 08/09 23:23:59.154  DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]explain INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11')08/09 23:23:59.341  DEBUG [Timer0] (SQLJob.java:85) -con query sql:select user() to con:MySQLConnection [id=3, lastTime=1502292239341, user=root, schema=db1, old shema=db1, borrowed=true, fromSlaveDB=false, threadId=49, charset=utf8, txIsolation=0, autocommit=true, attachment=null, respHandler=null, host=192.168.209.137, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]08/09 23:23:59.342  DEBUG [$_NIOREACTOR-0-RW] (PhysicalDatasource.java:403) -release channel MySQLConnection [id=3, lastTime=1502292239329, user=root, schema=db1, old shema=db1, borrowed=true, fromSlaveDB=false, threadId=49, charset=utf8, txIsolation=0, autocommit=true, attachment=null, respHandler=null, host=192.168.209.137, port=3306, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]08/09 23:24:02.624  DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11')08/09 23:24:02.625  DEBUG [$_NIOREACTOR-0-RW] (NonBlockingSession.java:113) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11'), route={   1 -> dn2{INSERT INTO t_order (ID,PROVINCE,SN,CREATE_TIME) VALUES(20002,'beijing','beijing20002_2017-01-11','2017-01-11')}} rrs 

从日志我们也可以分析：出日期为2017-01-09的数据SQL路由到了dn1节点，日期为2017-01-11的数据路由到了dn2节点，符合我们配置的Mycat路由规则。

3、指定分片字段查询

mysql> explain select * from t_order where create_time = '2017-01-09';+-----------+------------------------------------------------------------------+| DATA_NODE | SQL                                                              |+-----------+------------------------------------------------------------------+| dn1       | SELECT * FROM t_order WHERE create_time = '2017-01-09' LIMIT 100 |+-----------+------------------------------------------------------------------+1 row in set (0.21 sec)

可以看出： 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
查看后台mycat日志信息：

08/09 23:28:34.883  DEBUG [$_NIOREACTOR-0-RW] (ServerQueryHandler.java:56) -ServerConnection [id=1, schema=lyzdb, host=192.168.209.1, user=lyz,txIsolation=3, autocommit=true, schema=lyzdb]explain select * from t_order where create_time = '2017-01-09'08/09 23:28:34.909  DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:76) -SQLRouteCache  miss cache ,key:lyzdb select * from t_order where create_time = '2017-01-09'08/09 23:28:35.094  DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:59) -SQLRouteCache add cache ,key:lyzdb select * from t_order where create_time = '2017-01-09' value:select * from t_order where create_time = '2017-01-09', route={   1 -> dn1{SELECT *FROM t_orderWHERE create_time = '2017-01-09'LIMIT 100}

4、按照分片字段范围查询

mysql> explain select * from t_order where create_time < '2017-01-10';+-----------+------------------------------------------------------------------+| DATA_NODE | SQL                                                              |+-----------+------------------------------------------------------------------+| dn1       | SELECT * FROM t_order WHERE create_time < '2017-01-10' LIMIT 100 || dn2       | SELECT * FROM t_order WHERE create_time < '2017-01-10' LIMIT 100 |+-----------+------------------------------------------------------------------+2 rows in set (0.00 sec)

可以得出：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

5、按照非分片字段查询

mysql> explain select * from t_order where sn = 'beijing10001_2017-01-09';+-----------+----------------------------------------------------------------------+| DATA_NODE | SQL                                                                  |+-----------+----------------------------------------------------------------------+| dn1       | SELECT * FROM t_order WHERE sn = 'beijing10001_2017-01-09' LIMIT 100 || dn2       | SELECT * FROM t_order WHERE sn = 'beijing10001_2017-01-09' LIMIT 100 |+-----------+----------------------------------------------------------------------+2 rows in set (0.00 sec)

可以得出：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