死锁谜题：受害者不拥有任何资源，用来杀死以解决僵局

时间：2011-05-20 10:08:44

标签： sql sql-server sql-server-2008 deadlock database-deadlocks

我有一个奇怪的死锁图，其中MSSQL服务器2008选择的受害者不是死锁循环的一部分。 此死锁位于select和insert之间。 死锁资源是一个表，其中所有select都需要waitresource = "KEY: 6:72057594098810880 (ffffffffffff)"

问题1 ：这里的ffffffffffff是否意味着他们想在整个桌面上进行全范围锁定？还是整个关键范围？或其他什么？

我们遵循一条规则，其中表永远不会有主键id = 0的行。 我们进行这种检查的地方很少

select foo from bar where @someId = 0 OR SomeId = @someId。

我也知道SQL不会使表达式短路。因此，如果我通过@someId = 0，则不保证其他部分不会被评估。所以SQL可以在运行时SomeId = @someId执行。

Question2 ：由于在SomeId中无法找到0，因此SQL将在整个表（或行）上获取范围锁定，因此没有其他人插入0 id。正确？

考虑到这一假设，我将where子句更改为此

(CASE
       WHEN @someId = 0 THEN 1
       WHEN SomeId = @someId THEN 1
       ELSE 0
END = 1)

希望这会迫使评估订单。但我错了。我再次陷入僵局。 我已经附上了下面的死锁图。我已经重命名参与的表和sprocs（公司政策）

问题3 ：你知道我在这里缺少什么吗？

enter image description here 

  <deadlock-list>
 <deadlock victim="process722c508">
  <process-list>
   <process id="process722c508" taskpriority="0" logused="0" waitresource="KEY: 6:72057594098810880 (ffffffffffff)" waittime="6217" ownerId="24219001" transactionname="SELECT" lasttranstarted="2011-05-17T03:29:16.033" XDES="0x80073a40" lockMode="RangeS-S" schedulerid="13" kpid="20436" status="suspended" spid="91" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2011-05-17T03:29:16.033" lastbatchcompleted="2011-05-17T03:29:16.033" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24219001" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="fnGetTableResultAByBId" line="44" stmtstart="2246" stmtend="3566" sqlhandle="0x03000600800d7f0bda124000d99e00000000000000000000">
INSERT INTO @ReturnTable
    SELECT Foo, Bar
    FROM TheOneTable 
    WHERE ZId = @zId 
    AND (CASE
            WHEN @yId = 0 THEN 1
            WHEN YId = @yId THEN 1
            ELSE 0
        END = 1)
    AND (CASE
            WHEN @xId = 0 THEN 1
            WHEN XId = @xId THEN 1
            ELSE 0
        END = 1)     </frame>
     <frame procname="GetViewCByDId" line="9" stmtstart="272" stmtend="2984" sqlhandle="0x03000600c21629025d8f3f00d99e00000100000000000000">
    </frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 36247234]    </inputbuf>
   </process>
   <process id="process7185048" taskpriority="0" logused="0" waitresource="KEY: 6:72057594098810880 (ffffffffffff)" waittime="6217" ownerId="24218992" transactionname="SELECT" lasttranstarted="2011-05-17T03:29:16.030" XDES="0x179980430" lockMode="RangeS-S" schedulerid="13" kpid="30616" status="suspended" spid="79" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2011-05-17T03:29:16.030" lastbatchcompleted="2011-05-17T03:29:16.030" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24218992" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="fnGetTableResultAByBId" line="44" stmtstart="2246" stmtend="3566" sqlhandle="0x03000600800d7f0bda124000d99e00000000000000000000">
INSERT INTO @ReturnTable
    SELECT Foo, Bar
    FROM TheOneTable 
    WHERE ZId = @zId 
    AND (CASE
            WHEN @yId = 0 THEN 1
            WHEN YId = @yId THEN 1
            ELSE 0
        END = 1)
    AND (CASE
            WHEN @xId = 0 THEN 1
            WHEN XId = @xId THEN 1
            ELSE 0
        END = 1)     </frame>
     <frame procname="GetViewCByDId" line="9" stmtstart="272" stmtend="2984" sqlhandle="0x03000600c21629025d8f3f00d99e00000100000000000000">
</frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 36247234]    </inputbuf>
   </process>
   <process id="process7223048" taskpriority="0" logused="0" waitresource="KEY: 6:72057594098810880 (ffffffffffff)" waittime="5330" ownerId="24235090" transactionname="SELECT" lasttranstarted="2011-05-17T03:29:16.927" XDES="0x840d3b30" lockMode="RangeS-S" schedulerid="15" kpid="23452" status="suspended" spid="88" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2011-05-17T03:29:16.927" lastbatchcompleted="2011-05-17T03:29:16.927" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24235090" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="GetOneRowEByFId" line="11" stmtstart="260" stmtend="2456" sqlhandle="0x03000600db082c08ba823f00d99e00000100000000000000">
         SELECT TOP 1
         Col1, Col2, Col3

         FROM The2ndTable
         INNER JOIN [dbo].[TheOneTable] ON [dbo].[TheOneTable].[LinkBetweenOneAndTwoId]=[The2ndTable].[LinkBetweenOneAndTwoId]
         WHERE [dbo].[TheOneTable].ZId= @ActivityId and
         [TheOneTable].[n
     </frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 137103579]    </inputbuf>
   </process>
   <process id="process6334088" taskpriority="0" logused="0" waitresource="KEY: 6:72057594098810880 (ffffffffffff)" waittime="5668" ownerId="24229434" transactionname="SELECT" lasttranstarted="2011-05-17T03:29:16.587" XDES="0x17ea9ac90" lockMode="RangeS-S" schedulerid="12" kpid="5104" status="suspended" spid="86" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2011-05-17T03:29:16.587" lastbatchcompleted="2011-05-17T03:29:16.587" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24229434" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="GetOneRowEByFId" line="11" stmtstart="260" stmtend="2456" sqlhandle="0x03000600db082c08ba823f00d99e00000100000000000000">
SELECT TOP 1 
    Col1, Col2, Col3

    FROM The2ndTable
    INNER JOIN [dbo].[TheOneTable] ON [dbo].[TheOneTable].[LinkBetweenOneAndTwoId]=[The2ndTable].[LinkBetweenOneAndTwoId]
    WHERE [dbo].[TheOneTable].ZId= @ActivityId and
        [TheOneTable].[n</frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 137103579]    </inputbuf>
   </process>
   <process id="process8808e08" taskpriority="0" logused="0" waitresource="KEY: 6:72057594098810880 (ffffffffffff)" waittime="6652" ownerId="24217112" transactionname="SELECT" lasttranstarted="2011-05-17T03:29:15.610" XDES="0x833b5ca0" lockMode="RangeS-S" schedulerid="1" kpid="19752" status="suspended" spid="89" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2011-05-17T03:29:15.610" lastbatchcompleted="2011-05-17T03:29:15.610" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24217112" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="GetOneRowEByFId" line="11" stmtstart="260" stmtend="2456" sqlhandle="0x03000600db082c08ba823f00d99e00000100000000000000">
         SELECT TOP 1
         Col1, Col2, Col3

         FROM The2ndTable
         INNER JOIN [dbo].[TheOneTable] ON [dbo].[TheOneTable].[LinkBetweenOneAndTwoId]=[The2ndTable].[LinkBetweenOneAndTwoId]
         WHERE [dbo].[TheOneTable].ZId= @ActivityId and
         [TheOneTable].[n
     </frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 137103579]    </inputbuf>
   </process>
   <process id="process5c08988" taskpriority="0" logused="1644" waitresource="KEY: 6:72057594098810880 (91a0638558d2)" waittime="4889" ownerId="24214248" transactionname="user_transaction" lasttranstarted="2011-05-17T03:29:15.327" XDES="0x186609470" lockMode="RangeI-N" schedulerid="9" kpid="9000" status="suspended" spid="102" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2011-05-17T03:29:15.330" lastbatchcompleted="2011-05-17T03:29:15.330" clientapp=".Net SqlClient Data Provider" hostname="SOMEHOST" hostpid="28820" loginname="someloginname" isolationlevel="serializable (4)" xactid="24214248" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
    <executionStack>
     <frame procname="InsertIntoTheOneTable" line="25" stmtstart="1334" stmtend="2608" sqlhandle="0x03000600bbbacb5d25883f00d99e00000100000000000000">
INSERT INTO [dbo].[TheOneTable] (Some,Col,Here)
    VALUES (@some,@col,@here)     </frame>
    </executionStack>
    <inputbuf>
Proc [Database Id = 6 Object Id = 1573632699]    </inputbuf>
   </process>
  </process-list>
  <resource-list>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6b17a00" mode="RangeI-N" associatedObjectId="72057594098810880">
    <owner-list />
    <waiter-list>
     <waiter id="process722c508" mode="RangeS-S" requestType="wait" />
    </waiter-list>
   </keylock>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6b17a00" mode="RangeI-N" associatedObjectId="72057594098810880">
    <owner-list />
    <waiter-list>
     <waiter id="process7185048" mode="RangeS-S" requestType="wait" />
    </waiter-list>
   </keylock>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6b17a00" mode="RangeI-N" associatedObjectId="72057594098810880">
    <owner-list />
    <waiter-list>
     <waiter id="process7223048" mode="RangeS-S" requestType="wait" />
    </waiter-list>
   </keylock>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6b17a00" mode="RangeI-N" associatedObjectId="72057594098810880">
    <owner-list />
    <waiter-list>
     <waiter id="process6334088" mode="RangeS-S" requestType="wait" />
    </waiter-list>
   </keylock>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6b17a00" mode="RangeI-N" associatedObjectId="72057594098810880">
    <owner-list>
     <owner id="process5c08988" mode="RangeI-N" />
    </owner-list>
    <waiter-list>
     <waiter id="process8808e08" mode="RangeS-S" requestType="wait" />
    </waiter-list>
   </keylock>
   <keylock hobtid="72057594098810880" dbid="6" objectname="TheOneTable" indexname="PK_TheOneTable" id="lock6372e80" mode="RangeS-S" associatedObjectId="72057594098810880">
    <owner-list>
     <owner id="process7223048" mode="RangeS-S" />
     <owner id="process6334088" mode="RangeS-S" />
    </owner-list>
    <waiter-list>
     <waiter id="process5c08988" mode="RangeI-N" requestType="wait" />
    </waiter-list>
   </keylock>
  </resource-list>
 </deadlock>
</deadlock-list>

2 个答案:

答案 0 :(得分：3)

在锁定环境中，表及其相关索引是单独的实体。有时，表和它的索引之间会发生死锁，而不是在两个单独的表之间。

当在索引上获取锁定然后在相关表（即条形图）上获取另一个锁以进行数据查找时，问题很可能发生。在插入期间，这将以相反的顺序发生。首先，锁定并更新表（即条形图），然后锁定索引。

select foo 
from bar 
where @someId = 0 OR SomeId = @someId

您是否有/可以添加包含SomeId和foo的覆盖索引（以帮助选择）？这样你就可以完全避免查找并阻止问题的发生。

您可以发布查询计划而不是死锁帧吗？

答案 1 :(得分：0)

你介意尝试一些替代标准吗？我最近一直在使用这种方法（只使用NULL而不是0来表示所有值）：

SET @yId = NullIf(@yId, 0);
SET @xId = NullIf(@xId, 0);

...
WHERE
   @yId BETWEEN Coalesce(@yId, 0) AND Coalesce(@yId, 2147483647)
   AND @xId BETWEEN Coalesce(@xId, 0) AND Coalesce(@xId, 2147483647)

或者你可以完整地使用你的零：

WHERE
   @yId BETWEEN @yId AND Coalesce(NullIf(@yId, 0), 2147483647)
   AND @xId BETWEEN @xId AND Coalesce(NullIf(@xId, 0), 2147483647)

再考虑一下......只是为了审查，死锁只会因为资源获取顺序冲突而发生。资源不仅仅是一个表，而是行，范围，页面等。如果一次提交两个最初获得较小粒度锁定的查询，则将其锁定升级为与另一个进程具有的较小锁定重叠的内容，然后你陷入僵局。

那么，有没有什么方法可以提前获得更大的锁，避免获取更大的冲突锁，或者更改资源获取顺序？

你可以尝试使用听起来很糟糕的WITH (TABLOCKX)，但是如果你的@yId或@xId为0因此让你选择所有行，那么无论如何你都需要整张表。

你是否还考虑过试试OPTION (MAXDOP 1)是否有帮助？从理论上讲，为同一数据请求提供多个流可能会增加同时获取冲突锁的可能性。

表格是否有聚集索引？如果没有，请添加它，如果是，是否正在使用它还是可以强制使用它？这可能会使查询以不同的方式访问表，从而防止死锁。

发表您的评论，我会根据您的回复看看是否有更多想法。

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