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[数据库]记一次公司仓库数据库服务器死锁过程


记一次公司仓库数据库服务器死锁过程

 

仓库拣货卡死,排查了数据库的很多地方,都没有头绪,最后到SQL Server 错误日志里查看,终于发现了蛛丝马迹

EXEC xp_readerrorlog 0,1,NULL,NULL,'2015-09-21','2015-10-10','DESC'

   waiter id=process5c30e08 mode=U requestType=wait  waiter-list   owner id=process5c26988 mode=X  owner-list  keylock hobtid=72057597785604096 dbid=33 objectname=stoxxx.dbo.Orderxxx indexname=IX_PricingExpressProductCode_State id=lock17fa96980 mode=X associatedObjectId=72057597785604096   waiter id=process5c26988 mode=U requestType=wait  waiter-list   owner id=process5c30e08 mode=X  owner-list  keylock hobtid=72057597785604096 dbid=33 objectname=stoxxx.dbo.Orderxxx indexname=IX_PricingExpressProductCode_State id=lock87d69e780 mode=X associatedObjectId=72057597785604096 resource-list(@OperateState money,@HandledByNewWms bit,@State int,@OrderOut int)UPDATE [Orderxx] SET [OperateState] = @OperateState,[HandledByNewWms] = @HandledByNewWms WHERE (([Orderxxx].[State] = @State) And ([Orderxxx].[OrderOut] = @OrderOut) And ([Orderxxx].[PricingExpressProductCode] IN ('UKNIR')))    inputbufunknown     frame procname=unknown line=1 sqlhandle=0x000000000000000000000000000000000000000000000000UPDATE [Orderxxx] SET [OperateState] = @OperateState,[HandledByNewWms] = @HandledByNewWms WHERE (([Orderxxx].[State] = @State) And ([Orderxxx].[OrderOut] = @OrderOut) And ([Orderxxx].[PricingExpressProductCode] IN ('UKNIR')))     frame procname=adhoc line=1 stmtstart=134 sqlhandle=0x020000009d376d18a17e7ea51289d8caa2fb4de65c976389  executionStack  process id=process5c30e08 taskpriority=0 logused=10320 waitresource=KEY: 33:72057597785604096 (112399c2054a) waittime=4813 ownerId=31578743038 transactionname=user_transaction lasttranstarted=2015-09-24T10:22:58.410 XDES=0x372e95950 lockMode=U schedulerid=17 kpid=8496 status=suspended spid=153 sbid=0 ecid=0 priority=0 trancount=2 lastbatchstarted=2015-09-24T10:22:58.540 lastbatchcompleted=2015-09-24T10:22:58.540 clientapp=.Net SqlClient Data Provider hostname=CK1-WIN-WEB02 hostpid=37992 loginname=ck1.biz isolationlevel=read committed (2) xactid=31578743038 currentdb=33 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056(@OperateState money,@HandledByNewWms bit,@State int,@OrderOut int)UPDATE [Orderxxx] SET [OperateState] = @OperateState,[HandledByNewWms] = @HandledByNewWms WHERE (([Orderxxx].[State] = @State) And ([Orderxxx].[OrderOut] = @OrderOut) And ([Orderxxx].[PricingExpressProductCode] IN ('UKNIR')))    inputbufunknown     frame procname=unknown line=1 sqlhandle=0x000000000000000000000000000000000000000000000000UPDATE [Orderxxx] SET [OperateState] = @OperateState,[HandledByNewWms] = @HandledByNewWms WHERE (([Orderxxx].[State] = @State) And ([Orderxxx].[OrderOut] = @OrderOut) And ([Orderxxx].[PricingExpressProductCode] IN ('UKNIR')))     frame procname=adhoc line=1 stmtstart=134 sqlhandle=0x020000009d376d18a17e7ea51289d8caa2fb4de65c976389  executionStack  process id=process5c26988 taskpriority=0 logused=9892 waitresource=KEY: 33:72057597785604096 (70f5b089bb2b) waittime=4813 ownerId=31579268946 transactionname=user_transaction lasttranstarted=2015-09-24T10:27:01.357 XDES=0x98312f950 lockMode=U schedulerid=16 kpid=9184 status=suspended spid=454 sbid=0 ecid=0 priority=0 trancount=2 lastbatchstarted=2015-09-24T10:27:01.490 lastbatchcompleted=2015-09-24T10:27:01.487 clientapp=.Net SqlClient Data Provider hostname=CK1-WIN-WEB02 hostpid=37992 loginname=ck1.biz isolationlevel=read committed (2) xactid=31579268946 currentdb=33 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056 process-list deadlock victim=process5c26988deadlock-list

 

咋一看上面的错误信息,可以发现两条相同的语句造成的死锁,但是这么短的语句不可能持有排他锁太久

 

 

再仔细分析一下错误日志,发现都死锁在同一个非聚集索引上,再问了一下开发,开发那边说,这条语句是在一个大事务里面,这个事务会做7、8件事

 

索引属性

 

 

还有索引里面的数据,发现很多重复值

 

 

SQL语句是这样的

(@OperateState money,@HandledByNewWms bit,@State int,@OrderOut int)@HandledByNewWms=(1) @OperateState=($1.0000) @OrderOut=(4055484) @State=(3) UPDATE [Orderxxx] SET [OperateState] = $1.0000,[HandledByNewWms] = 1WHERE (([Orderxxx].[State] = 3) And ([Orderxxx].[OrderOut] = 4055484) And ([Orderxxx].[PricingExpressProductCode] IN ('UKRRM','UKRLE')))

 

 

下图为语句生成的执行计划

 

 

当时的情况是大量SQL语句被阻塞,而阻塞的语句正是下面这条语句

UPDATE [Orderxxx] SET [OperateState] = $1.0000,[HandledByNewWms] = 1WHERE (([Orderxxx].[State] = 3) And ([Orderxxx].[OrderOut] = 4055484) And ([Orderxxx].[PricingExpressProductCode] IN ('UKRRM','UKRLE')))

 

 

解决方法

上面得出几个症状

1、update语句是在一个大事务里面,事务太大导致其他session等待排他锁的时间变长

2、大家都在使用同一个非聚集索引,并扫描PricingExpressProductCode字段

3、索引里的重复值很多

 

从上面的症状基本可以判断,这个非聚集索引无啥用,可以禁用之

ALTER INDEX [IX_PricingExpressProductCode_State] ON [dbo].[Orderxxx] DISABLE

禁用之后,死锁消失,问题解决,仓库的怨气也随之消失

 

这一次排查过程时间有点长,但是很好定位,SQL Server错误日志给出了足够的信息定位死锁问题,所以遇到问题的时候一定要分析清楚日志

 

 

如有不对的地方,欢迎大家拍砖o(∩_∩)o