mycat 分页慢原理解析、mycat跨事务解惑、mycat注解调用存储过程分析

１结合Ｍｙｃａｔ日志，分析select * from travelrecord order by id limit100000,100 的运行过程，解释下当limit M,N中的M非常大的情况下。为什么查询结果会变慢非常多

1.1mycat控制命令台显示。explain出来走了全部的节点

         mysql>explain select * from travelrecord order by id limit 100000,100 ;
         +-----------+--------------------------------------------------------+
         |DATA_NODE | SQL                                                   |
         +-----------+--------------------------------------------------------+
         |dn1       | SELECT * FROM travelrecordORDER BY id LIMIT 0, 100100 |
         |dn2       | SELECT * FROM travelrecordORDER BY id LIMIT 0, 100100 |
         |dn3       | SELECT * FROM travelrecordORDER BY id LIMIT 0, 100100 |
         +-----------+--------------------------------------------------------+
         3rows in set (0.01 sec)

         mysql>

本文源自mchdba（黄杉）博客地址：http://blog.csdn.net/mchdba/article/details/50719120，未经过mchdba同意，谢绝转载

---

1.2看后台mycat.log日志：

         02/1417:52:30.103  DEBUG [$_NIOREACTOR-0-RW](ServerQueryHandler.java:56) -ServerConnection [id=3, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]explainselect * from travelrecord order by id limit 1000000,100
         02/1417:52:30.103  DEBUG [$_NIOREACTOR-0-RW](EnchachePool.java:76) -SQLRouteCache miss cache ,key:TESTDB select * from travelrecord order by id limit1000000,100
         02/1417:52:30.105  DEBUG [$_NIOREACTOR-0-RW] (EnchachePool.java:59)-SQLRouteCache add cache ,key:TESTDB select * from travelrecord order by idlimit 1000000,100 value:select * from travelrecord order by id limit1000000,100, route={
            1 -> dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            2 -> dn2{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            3 -> dn3{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
         }
         02/1417:52:33.880  DEBUG [$_NIOREACTOR-0-RW](ServerQueryHandler.java:56) -ServerConnection [id=3, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]select* from travelrecord order by id limit 1000000,100
         02/1417:52:33.881  DEBUG [$_NIOREACTOR-0-RW](EnchachePool.java:76) -SQLRouteCache miss cache ,key:TESTDBselect * from travelrecord order by id limit1000000,100
         02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](EnchachePool.java:59) -SQLRouteCache add cache ,key:TESTDBselect * fromtravelrecord order by id limit 1000000,100 value:select * from travelrecordorder by id limit 1000000,100, route={
            1 -> dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            2 -> dn2{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            3 -> dn3{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
         }
        02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](NonBlockingSession.java:113) -ServerConnection [id=3, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]select* from travelrecord order by id limit 1000000,100, route={
            1 -> dn1{SELECT *
         FROMtravelrecord
         ORDERBY id

        02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](NonBlockingSession.java:113) -ServerConnection [id=3, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]select* from travelrecord order by id limit 1000000,100, route={
            1 -> dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            2 -> dn2{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
            3 -> dn3{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}
         }rrs
         02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:82) -execute mutinode query select * from travelrecordorder by id limit 1000000,100
         02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:97) -has data merge logic
         02/1417:52:33.882  DEBUG [$_NIOREACTOR-0-RW](PhysicalDBPool.java:452) -select read source hostM1 for dataHost:wgq_idc_mon_1_12
         02/1417:52:33.883  DEBUG [$_NIOREACTOR-0-RW](PhysicalDBPool.java:452) -select read source hostM1 fordataHost:wgq_idc_mon_1_12
         02/1417:52:33.883  DEBUG [$_NIOREACTOR-0-RW](PhysicalDBPool.java:452) -select read source hostM1 for dataHost:wgq_idc_mon_1_12
         02/1417:52:33.883  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=19, lastTime=1455443553868, user=root, schema=db1, oldshema=db1, borrowed=true, fromSlaveDB=false, threadId=220, charset=latin1,txIsolation=3, autocommit=true, attachment=dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@b47af37,writeQueue=0, modifiedSQLExecuted=false]
         02/1417:52:33.884  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:241) -on row end reseponse MySQLConnection [id=25,lastTime=1455443553868, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=227, charset=latin1, txIsolation=3,autocommit=true, attachment=dn3{SELECT *
         FROMtravelrecord


         02/1417:52:33.883  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=19, lastTime=1455443553868, user=root, schema=db1, oldshema=db1, borrowed=true, fromSlaveDB=false, threadId=220, charset=latin1,txIsolation=3, autocommit=true, attachment=dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@b47af37,writeQueue=0, modifiedSQLExecuted=false]
         02/1417:52:33.884  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:241) -on row end reseponse MySQLConnection [id=25,lastTime=1455443553868, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=227, charset=latin1, txIsolation=3,autocommit=true, attachment=dn3{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=false]

        02/1417:52:33.884  DEBUG [$_NIOREACTOR-3-RW](DataMergeService.java:94) -field metadata inf:[ID=ColMeta [colIndex=0,colType=8], DAYS=ColMeta [colIndex=4, colType=3], TRAVELDATE=ColMeta[colIndex=2, colType=10], USER_ID=ColMeta [colIndex=1, colType=253],FEE=ColMeta [colIndex=3, colType=246]]
         02/1417:52:33.884  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=25,lastTime=1455443553868, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=227, charset=latin1, txIsolation=3,autocommit=true, attachment=dn3{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=false]





        02/1417:52:33.885  DEBUG [$_NIOREACTOR-1-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=25,lastTime=1455443553868, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=227, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/1417:52:33.886  DEBUG [$_NIOREACTOR-3-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=19,lastTime=1455443553868, user=root, schema=db1, old shema=db1, borrowed=true,fromSlaveDB=false, threadId=220, charset=latin1, txIsolation=3,autocommit=true, attachment=dn1{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100}, respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@b47af37,writeQueue=0, modifiedSQLExecuted=false]
        02/1417:52:33.886  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=19,lastTime=1455443553868, user=root, schema=db1, old shema=db1, borrowed=true,fromSlaveDB=false, threadId=220, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111, port=3317,statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/1417:52:33.886  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:241) -on row end reseponse MySQLConnection [id=42,lastTime=1455443553868, user=root, schema=db2, old shema=db2, borrowed=true,fromSlaveDB=false, threadId=234, charset=latin1, txIsolation=3,autocommit=true, attachment=dn2{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=false]
         02/1417:52:33.886  DEBUG [$_NIOREACTOR-3-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=42,lastTime=1455443553868, user=root, schema=db2, old shema=db2, borrowed=true,fromSlaveDB=false, threadId=234, charset=latin1, txIsolation=3,autocommit=true, attachment=dn2{SELECT *
         FROMtravelrecord
         ORDERBY id
         LIMIT0, 1000100},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@f35a686, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
        02/1417:52:33.886  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=42,lastTime=1455443553868, user=root, schema=db2, old shema=db2, borrowed=true,fromSlaveDB=false, threadId=234, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/1417:52:33.887  DEBUG [BusinessExecutor5](DataMergeService.java:296) -prepare mpp merge result for select * fromtravelrecord order by id limit 1000000,100
         02/1417:52:33.887  DEBUG [BusinessExecutor5](MultiNodeQueryHandler.java:324) -last packet id:8

路由里面是先查limit 0,1000000条。然后再查出limit 0,1000100条记录。在这个基础上查出100条（prepare mpp mergeresult for select * from travelrecord order by id limit 1000000,100），所以假设这个M=1000000越来越大，一次性拉的数据就越大，这样就越来越慢了，那么须要查询的数据就比較多

---

２结合Mycat日志。分析跨分片事务的运行过程。以一个正常的跨分片SQL的事务过程，以及,一个错误SQL为例（比方某个分片上主键冲突或其它ＳＱＬ错误，导致无法运行成功）分别加, 以说明

2.1 正常的跨分片事务分析

运行情况：

         mysql>set autocommit=0
         mysql>update order040302 set SN=concat(SN,'-mycat');
         QueryOK, 2 rows affected (0.01 sec)
         Rowsmatched: 1  Changed: 1  Warnings: 0
         mysql>commit;

mycat.log日志显示：

         02/1800:01:24.351  DEBUG [$_NIOREACTOR-1-RW](ServerQueryHandler.java:56) -ServerConnection [id=4, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]updateorder040302 set SN=concat(SN,'-mycat')
        02/1800:01:24.356  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:113) -ServerConnection [id=4, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]updateorder040302 set SN=concat(SN,'-mycat'), route={
            1 -> dn21{update order040302 setSN=concat(SN,'-mycat')}
            2 -> dn22{update order040302 setSN=concat(SN,'-mycat')}
         }rrs
         02/1800:01:24.356  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:82) -execute mutinode query update order040302 setSN=concat(SN,'-mycat')
         02/1800:01:24.357  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=7, lastTime=1455724884356, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=218, charset=latin1,txIsolation=3, autocommit=true, attachment=dn21{update order040302 setSN=concat(SN,'-mycat')},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@23eca0d1,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@71a27302,writeQueue=0, modifiedSQLExecuted=true]
         02/1800:01:24.358  DEBUG [$_NIOREACTOR-2-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=30, lastTime=1455724884356, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=200, charset=latin1,txIsolation=3, autocommit=true, attachment=dn22{update order040302 setSN=concat(SN,'-mycat')},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@23eca0d1,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/1800:01:24.359  DEBUG [$_NIOREACTOR-2-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=30,lastTime=1455724884356, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=200, charset=latin1, txIsolation=3,autocommit=true, attachment=dn22{update order040302 setSN=concat(SN,'-mycat')},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@23eca0d1,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/1800:01:24.359  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=7, lastTime=1455724884356, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=218, charset=latin1,txIsolation=3, autocommit=true, attachment=dn21{update order040302 setSN=concat(SN,'-mycat')}, respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@23eca0d1,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/1800:01:24.359  DEBUG [$_NIOREACTOR-3-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=7,lastTime=1455724884356, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=218, charset=latin1, txIsolation=3,autocommit=true, attachment=dn21{update order040302 setSN=concat(SN,'-mycat')}, respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@23eca0d1,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/1800:01:24.359  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=7,lastTime=1455724884356, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=218, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]

分析结果：update语句是改动全部的节点上的数据，02/18 00:01:24.356处NonBlockingSession启动了分布式事务，以下就分别在02/18 00:01:24.359有2处 NonBlockingSession.java:229在dn21、dn22上面运行了2遍，大家看到在2个节点dn21和dn22都运行完毕后，才有(PhysicalDatasource.java:403)-release channel MySQLConnection開始关闭释放连接，也就是说等全部节点都运行完毕后才结束整个事务。

---

2.2 非正常的sql事务运行，有一处报错的情况下（失败经过）

     准备数据。须要一个节点成功，一个节点失败，所以准备拿SN字段的长度来做实验。一个超过报错。一个没有超过不报错

2.2.1 查看表结构：

 mysql>show create table order040302;
+-------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
         |Table       | Create Table                                                                                                                                                                                                                                                 |
+-------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
         |order040302 | CREATE TABLE `order040302` (
           `ID` int(11) NOT NULL AUTO_INCREMENT,
           `CODE` varchar(64) DEFAULT NULL,
           `SN` varchar(64) DEFAULT NULL,
           `CREATE_TIME` datetime DEFAULT NULL,
           PRIMARY KEY (`ID`)
         )ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 |
+-------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
         1row in set (0.00 sec)

  mysql>

改动数据，设置成如此，一会就能够update一个节点失败一个节点成功了，在ID=1的节点上由于长度超过64报错。而在ID=2的节点上面则长度小于64而正常运行：

mysql> update order040302 set SN =concat('',SN,'___',SN) where ID=1;
         QueryOK, 1 row affected (0.01 sec)
         Rowsmatched: 1  Changed: 1  Warnings: 0

 mysql>select length(t1.SN),t1.* from order040302 t1;
         +---------------+----+------------+-------------------------------------------------------+---------------------+
         |length(t1.SN) | ID | CODE       | SN                                                   | CREATE_TIME         |
         +---------------+----+------------+-------------------------------------------------------+---------------------+
         |            53 |  1 | 0-10000020 |beijing_03-10000020-mycat___beijing_03-10000020-mycat | 2016-02-13 00:40:27 |
         |            26 |  2 | 1-10000020 |shanghai_10-10000020-mycat                            | 2016-02-1300:40:18 |
         +---------------+----+------------+-------------------------------------------------------+---------------------+
         2rows in set (0.00 sec)

mysql>   update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN) ;

---

2.2.2 mycat.log日志例如以下：

         02/2205:44:39.666  DEBUG [$_NIOREACTOR-0-RW](ServerQueryHandler.java:56) -ServerConnection [id=1, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]updateorder040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN)
        02/2205:44:39.821  DEBUG [$_NIOREACTOR-0-RW](NonBlockingSession.java:113) -ServerConnection [id=1, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]updateorder040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN), route={
            1 -> dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}
            2 -> dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}
         }rrs
         02/2205:44:39.827  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:82) -execute mutinode query update order040302 setSN = concat('fenpianyigechenggong_yigeshibai_',SN)
         02/2205:44:39.830  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=7, lastTime=1456091079827, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=245, charset=latin1,txIsolation=3, autocommit=true, attachment=dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@1c70f0b1,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@64b49aaa,writeQueue=0, modifiedSQLExecuted=true]
         02/2205:44:39.831  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=12, lastTime=1456091079827, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=222, charset=latin1,txIsolation=3, autocommit=true, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}, respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@1c70f0b1,host=110.254.11.111, port=3327,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@306b3db1,writeQueue=0, modifiedSQLExecuted=true]
         02/2205:44:39.831  DEBUG [$_NIOREACTOR-3-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=7,lastTime=1456091079827, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=245, charset=latin1, txIsolation=3,autocommit=true, attachment=dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@1c70f0b1,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@64b49aaa,writeQueue=0, modifiedSQLExecuted=true]
         02/2205:44:39.832  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=7,lastTime=1456091079827, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=245, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/2205:44:39.832  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=12, lastTime=1456091079827, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=222, charset=latin1,txIsolation=3, autocommit=true, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@1c70f0b1,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2205:44:39.832   WARN [$_NIOREACTOR-3-RW](MultiNodeHandler.java:127) -error response from MySQLConnection [id=7,lastTime=1456091079827, user=root, schema=db3, old shema=db3, borrowed=false,fromSlaveDB=false, threadId=245, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false] err Datatoo long for column 'SN' at row 1 code:1406
         02/2205:44:39.833  DEBUG [$_NIOREACTOR-0-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=12,lastTime=1456091079827, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=222, charset=latin1, txIsolation=3,autocommit=true, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@1c70f0b1,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
        02/2205:44:39.834  DEBUG [$_NIOREACTOR-0-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=12,lastTime=1456091079827, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=222, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111, port=3327,statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/2205:44:39.835  DEBUG [$_NIOREACTOR-0-RW](MultiNodeHandler.java:194) -error all end ,clear session resource

从日志记录里面能够看出：[NIOREACTOR−3−RW]dn21节点失败。报错errDatatoolongforcolumn′SN′atrow1code:1406。[_NIOREACTOR-0-RW]节点dn22成功了，所以最后提示-error all end ,clear sessionresource，整个事务退出。清空当前会话资源，结论就是一个节点dn21失败。单节点回退。可是成功的节点dn22不会回退。这是怎么回事呢？查看运行后的数据结果例如以下：

         mysql>select length(t1.SN),t1.* from order040302 t1;
         +---------------+----+------------+------------------------------------------------------------+---------------------+
         |length(t1.SN) | ID | CODE       | SN                                                        | CREATE_TIME         |
         +---------------+----+------------+------------------------------------------------------------+---------------------+
         |            53 |  1 | 0-10000020 |beijing_03-10000020-mycat___beijing_03-10000020-mycat      | 2016-02-13 00:40:27 |
         |            58 |  2 | 1-10000020 |fenpianyigechenggong_yigeshibai_shanghai_10-10000020-mycat | 2016-02-1300:40:18 |
         +---------------+----+------------+------------------------------------------------------------+---------------------+
         2rows in set (0.06 sec)

  mysql>  

可见，我这个不是事务，事务会全部一起回退的。
mycat窗体中怎样开启事务？

2.3 怎样mysql窗体那样，在mycat窗体开启事务

2.3.1 开启事务，手动提交

     mysql>set autocommit=0;
     QueryOK, 0 rows affected (0.00 sec)

     mysql>update order040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN) ;
     ERROR1105 (HY000): Data too long for column 'SN' at row 1
     mysql>commit;
     ERROR1003 (HY000): Transaction error, need to rollback.
     mysql>
     mysql>select length(t1.SN),t1.* from order040302 t1;
     ERROR1003 (HY000): Transaction error, need to rollback.Data too long for column 'SN'at row 1
     mysql>
     mysql>rollback;
     QueryOK, 0 rows affected (0.01 sec)

     mysql>
     mysql>select length(t1.SN),t1.* from order040302 t1;
     +---------------+----+------------+-------------------------------------------------------+---------------------+
     |length(t1.SN) | ID | CODE       | SN                                                   | CREATE_TIME         |
     +---------------+----+------------+-------------------------------------------------------+---------------------+
     |            53 |  1 | 0-10000020 |beijing_03-10000020-mycat___beijing_03-10000020-mycat | 2016-02-13 00:40:27 |
     |            26 |  2 | 1-10000020 |shanghai_10-10000020-mycat                            | 2016-02-1300:40:18 |
     +---------------+----+------------+-------------------------------------------------------+---------------------+
     2rows in set (0.09 sec)

     mysql>

---

2.3.2 后台mycat.log日志例如以下，run失败信息例如以下：

         02/2217:54:25.035  DEBUG [$_NIOREACTOR-1-RW](ServerQueryHandler.java:56) -ServerConnection [id=2, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=false, schema=TESTDB]updateorder040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN)
        02/2217:54:25.187  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:113) -ServerConnection [id=2, schema=TESTDB, host=127.0.0.1,user=test,txIsolation=3, autocommit=false, schema=TESTDB]update order040302 setSN = concat('fenpianyigechenggong_yigeshibai_',SN), route={
            1 -> dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}
            2 -> dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}
         }rrs
         02/2217:54:25.193  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:82) -execute mutinode query update order040302 setSN = concat('fenpianyigechenggong_yigeshibai_',SN)
         02/2217:54:25.195  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=7, lastTime=1456134865193, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=278, charset=latin1,txIsolation=0, autocommit=true, attachment=dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:54:25.196  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=17, lastTime=1456134865193, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=259, charset=latin1,txIsolation=0, autocommit=true, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3327,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@46e9d255,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:54:25.196  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=7, lastTime=1456134865193, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=278, charset=latin1,txIsolation=3, autocommit=false, attachment=dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:54:25.196  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=17, lastTime=1456134865193, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=259, charset=latin1,txIsolation=3, autocommit=false, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)}, respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3327,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@46e9d255,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:54:25.197   WARN [$_NIOREACTOR-3-RW](MultiNodeHandler.java:127) -error response from MySQLConnection [id=7,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=278, charset=latin1, txIsolation=3,autocommit=false, attachment=dn21{update order040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true] err Data too long for column 'SN' atrow 1 code:1406
         02/2217:54:25.197  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=17, lastTime=1456134865193, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=259, charset=latin1,txIsolation=3, autocommit=false, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2217:54:25.199  DEBUG [$_NIOREACTOR-1-RW](MultiNodeHandler.java:194) -error all end ,clear session resource      

---

2.3.3后台mycat.log日志，rollback操作日志例如以下：

         02/2217:57:17.432  DEBUG [$_NIOREACTOR-1-RW](ServerQueryHandler.java:56) -ServerConnection [id=2, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=false,schema=TESTDB]rollback
         02/2217:57:17.434  DEBUG [$_NIOREACTOR-1-RW] (RollbackNodeHandler.java:71)-rollback job run for MySQLConnection [id=7, lastTime=1456134865193, user=root,schema=db3, old shema=db3, borrowed=true, fromSlaveDB=false, threadId=278,charset=latin1, txIsolation=3, autocommit=false, attachment=dn21{updateorder040302 set SN = concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:57:17.435  DEBUG [$_NIOREACTOR-1-RW](RollbackNodeHandler.java:71) -rollback job run for MySQLConnection [id=17,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=259, charset=latin1, txIsolation=3,autocommit=false, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@243cc381,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2217:57:17.436  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:361) -clear session resourcesorg.opencloudb.server.NonBlockingSession@4483dae0
         02/2217:57:17.436  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=7,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=278, charset=latin1, txIsolation=3,autocommit=false, attachment=dn21{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.RollbackNodeHandler@2c96cb44,host=110.254.11.111, port=3317, statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:57:17.438  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=17,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=259, charset=latin1, txIsolation=3,autocommit=false, attachment=dn22{update order040302 set SN =concat('fenpianyigechenggong_yigeshibai_',SN)},respHandler=org.opencloudb.mysql.nio.handler.RollbackNodeHandler@2c96cb44,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2217:57:17.438  DEBUG [$_NIOREACTOR-3-RW](RollbackReleaseHandler.java:58) -autocomit is false,but no commit or rollback,so mycat rollbacked backend conn MySQLConnection [id=7,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=278, charset=latin1, txIsolation=3,autocommit=false, attachment=null,respHandler=org.opencloudb.mysql.nio.handler.RollbackReleaseHandler@56683a8d,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@4ff5e91e,writeQueue=0, modifiedSQLExecuted=true]
         02/2217:57:17.439  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=7,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=278, charset=latin1, txIsolation=3,autocommit=false, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/2217:57:17.439  DEBUG [$_NIOREACTOR-1-RW](RollbackReleaseHandler.java:58) -autocomit is false,but no commit or rollback,so mycat rollbacked backend conn MySQLConnection [id=17,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=259, charset=latin1, txIsolation=3,autocommit=false, attachment=null,respHandler=org.opencloudb.mysql.nio.handler.RollbackReleaseHandler@429eb61a,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
        02/2217:57:17.440  DEBUG [$_NIOREACTOR-1-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=17,lastTime=1456134865193, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=259, charset=latin1, txIsolation=3,autocommit=false, attachment=null, respHandler=null, host=110.254.11.111,port=3327, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]

看到在运行update的时候，有报错信息：在dn21节点上面err Data too long forcolumn ‘SN’ at row 1 code:1406，所以依照理论上不论什么节点错误发生了，就面临rollback的错误信息，不论什么不论什么都会提示报错信息。仅仅能运行rollback来恢复。PS：这里眼下的mycat版本号没有办法做到在update失败后自己主动rollback，须要手动rollback操作。

---

３创建一个在多个分片上存在的存储过程。存储过程能够是统计某个表的记录个数并返回。然后用Mycat注解方式完毕调用

3.1准备好的简单的存储过程

         DELIMITER$$
         CREATE
                   PROCEDUREdb3.pro_select()
                   BEGIN
                            SELECTCOUNT(1) FROM order040302;
                   END$$
         DELIMITER;

3.2在各mysql节点上运行创建存储过程

dn21节点上的mysql窗体上：

         mysql>DELIMITER $$
         mysql>CREATE
                   ->     PROCEDURE `db3`.`pro_select`()
                   ->     BEGIN
                   ->SELECT COUNT(1) FROM order040302;
                   ->     END$$
         QueryOK, 0 rows affected (0.01 sec)

         mysql>DELIMITER ;
         mysql>

dn22节点上的mysql窗体上：

         mysql>DELIMITER $$
         mysql>CREATE
                   ->     PROCEDURE `db3`.`pro_select`()
                   ->     BEGIN
                   ->SELECT COUNT(1) FROM order040302;
                   ->     END$$
         QueryOK, 0 rows affected (0.01 sec)

         mysql>DELIMITER ;
         mysql>

检查存储过程：

         mysql>select * from information_schema.ROUTINESG
         ***************************1. row ***************************
                               SPECIFIC_NAME: pro_select
                             ROUTINE_CATALOG: def
                              ROUTINE_SCHEMA: db3
                                     ROUTINE_NAME:pro_select
                                     ROUTINE_TYPE:PROCEDURE
                                        DATA_TYPE:
         CHARACTER_MAXIMUM_LENGTH:NULL
           CHARACTER_OCTET_LENGTH: NULL
                      NUMERIC_PRECISION: NULL
                               NUMERIC_SCALE: NULL
                     DATETIME_PRECISION: NULL
                     CHARACTER_SET_NAME: NULL
                              COLLATION_NAME: NULL
                              DTD_IDENTIFIER: NULL
                                     ROUTINE_BODY:SQL
                     ROUTINE_DEFINITION: BEGIN
         SELECTCOUNT(1) FROM order040302;
                   END
                               EXTERNAL_NAME: NULL
                      EXTERNAL_LANGUAGE: NULL
                             PARAMETER_STYLE: SQL
                            IS_DETERMINISTIC: NO
                             SQL_DATA_ACCESS: CONTAINS SQL
                                               SQL_PATH:NULL
                               SECURITY_TYPE: DEFINER
                                                CREATED: 2016-02-22 19:17:12
                                     LAST_ALTERED:2016-02-22 19:17:12
                                               SQL_MODE:STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION
                             ROUTINE_COMMENT:
                                                DEFINER: root@localhost
                   CHARACTER_SET_CLIENT:latin1
                   COLLATION_CONNECTION:latin1_swedish_ci
                     DATABASE_COLLATION: utf8mb4_general_ci
         1row in set (0.00 sec)

         mysql>

然后在mycat中运行：

         mysql>/*!mycat:sql=select * from order040302 where ID=2*/ call pro_select();
         +----------+
         |COUNT(1) |
         +----------+
         |        1 |
         |        1 |
         +----------+
         2rows in set (0.01 sec)

         QueryOK, 0 rows affected (0.01 sec)

         mysql>

问题，为啥是2行记录，不知道能够不能够并成一行记录呢？
普通sql到了最后会有例如以下：

02/23 00:07:21.478  DEBUG [BusinessExecutor0] (DataMergeService.java:296) -prepare mpp merge result for select count(*) from order040302
02/23 00:07:21.479  DEBUG [BusinessExecutor0] (MultiNodeQueryHandler.java:324) -last packet id:5

的聚合操作，有了这个merge result操作后，就会把2条记录变成一条记录。可是mycat注解后的运行sql显示注解后，没有这一个merge result的操作，所以是2条记录。

哇塞。我好伟大，发现了当中的差别，可是那么新问题来了，怎么完好注解后生成的2条记录变成为1条记录额？

---

3.3看后台mycat.log日志：

看到日志中42.293记录。走的route路由进入dn21和dn22节点上面，终于运行的是注解的-execute mutinode query select * from order040302。例如以下所看到的：

02/22 20:19:42.292  DEBUG [$_NIOREACTOR-1-RW](ServerQueryHandler.java:56) -ServerConnection [id=10, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true,schema=TESTDB]/*!mycat:sql=select * from order040302*/ call pro_select()
         02/22 20:19:42.293  DEBUG [$_NIOREACTOR-1-RW](NonBlockingSession.java:113) -ServerConnection [id=10, schema=TESTDB,host=127.0.0.1, user=test,txIsolation=3, autocommit=true, schema=TESTDB]select* from order040302, route={
            1 -> dn21{call pro_select()}
            2 -> dn22{call pro_select()}
         } rrs
         02/22 20:19:42.293  DEBUG [$_NIOREACTOR-1-RW](MultiNodeQueryHandler.java:82) -execute mutinode query select * fromorder040302
         02/2220:19:42.295  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:falsefrom MySQLConnection [id=4, lastTime=1456143582284, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=280, charset=latin1,txIsolation=3, autocommit=true, attachment=dn21{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@939bc30,writeQueue=0, modifiedSQLExecuted=true]
         02/2220:19:42.295  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:241) -on row end reseponse MySQLConnection [id=11,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=254, charset=latin1, txIsolation=3, autocommit=true,attachment=dn22{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2220:19:42.295  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:241) -on row end reseponse MySQLConnection [id=4,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=280, charset=latin1, txIsolation=3,autocommit=true, attachment=dn21{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3317,statusSync=org.opencloudb.mysql.nio.MySQLConnection$StatusSync@939bc30,writeQueue=0, modifiedSQLExecuted=true]
         02/2220:19:42.296  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:280) -last packet id:6
         02/2220:19:42.295  DEBUG [$_NIOREACTOR-3-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=11, lastTime=1456143582284, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=254, charset=latin1,txIsolation=3, autocommit=true, attachment=dn22{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2220:19:42.296  DEBUG [$_NIOREACTOR-0-RW](MultiNodeQueryHandler.java:171) -received ok response ,executeResponse:truefrom MySQLConnection [id=4, lastTime=1456143582284, user=root, schema=db3, oldshema=db3, borrowed=true, fromSlaveDB=false, threadId=280, charset=latin1,txIsolation=3, autocommit=true, attachment=dn21{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2220:19:42.296  DEBUG [$_NIOREACTOR-3-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=11,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=254, charset=latin1, txIsolation=3,autocommit=true, attachment=dn22{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3327, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
         02/2220:19:42.296  DEBUG [$_NIOREACTOR-0-RW](NonBlockingSession.java:229) -release connection MySQLConnection [id=4,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=280, charset=latin1, txIsolation=3,autocommit=true, attachment=dn21{call pro_select()},respHandler=org.opencloudb.mysql.nio.handler.MultiNodeQueryHandler@ba5d1a4,host=110.254.11.111, port=3317, statusSync=null, writeQueue=0,modifiedSQLExecuted=true]
        02/2220:19:42.296  DEBUG [$_NIOREACTOR-3-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=11,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveDB=false, threadId=254, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111, port=3327,statusSync=null, writeQueue=0, modifiedSQLExecuted=false]
         02/2220:19:42.297  DEBUG [$_NIOREACTOR-0-RW](PhysicalDatasource.java:403) -release channel MySQLConnection [id=4,lastTime=1456143582284, user=root, schema=db3, old shema=db3, borrowed=true,fromSlaveD**重点内容**B=false, threadId=280, charset=latin1, txIsolation=3,autocommit=true, attachment=null, respHandler=null, host=110.254.11.111,port=3317, statusSync=null, writeQueue=0, modifiedSQLExecuted=false]