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Learning_DBAdmin
Asked: 2019-04-10 04:56:27 +0800 CST

死锁图和解释，避免的解决方案

  • 772

我支持基于供应商的应用程序，它充满了块和死锁。死锁主要涉及两个或三个进程，但我昨天注意到，它涉及 9 个 SPID。

有人可以帮助我理解这个死锁图以及如何避免这种情况的解决方案。

<deadlock><victim-list><victimProcess id="process2ff017c28"/><victimProcess id="process2f1538108"/><victimProcess id="process2f618d088"/><victimProcess id="process2f6d828c8"/><victimProcess id="process2f6d83848"/><victimProcess id="process2da9b5468"/><victimProcess id="process2efac7468"/><victimProcess id="process2efac7848"/></victim-list><process-list><process id="process2ff017c28" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4412" ownerId="284194209" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:29:07.323" XDES="0x2a785f800" lockMode="IX" schedulerid="1" kpid="9052" status="suspended" spid="63" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.733" lastbatchcompleted="2019-04-08T15:30:58.733" lastattention="1900-01-01T00:00:00.733" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284194209" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2f1538108" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4411" ownerId="284107628" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:24:11.843" XDES="0xdacf54e0" lockMode="IX" schedulerid="1" kpid="7272" status="suspended" spid="73" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.737" lastbatchcompleted="2019-04-08T15:30:58.727" lastattention="1900-01-01T00:00:00.727" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284107628" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2f618d088" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4620" ownerId="284193487" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:28:59.513" XDES="0x20df303b0" lockMode="IX" schedulerid="2" kpid="2088" status="suspended" spid="79" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.527" lastbatchcompleted="2019-04-08T15:30:58.527" lastattention="1900-01-01T00:00:00.527" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284193487" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2f6d828c8" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4302" ownerId="284194269" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:29:07.743" XDES="0x25090c6d0" lockMode="IX" schedulerid="3" kpid="3140" status="suspended" spid="105" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.843" lastbatchcompleted="2019-04-08T15:30:58.843" lastattention="1900-01-01T00:00:00.843" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284194269" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2f6d83848" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4319" ownerId="284178892" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:26:38.450" XDES="0xb83c63b0" lockMode="IX" schedulerid="3" kpid="7372" status="suspended" spid="81" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.827" lastbatchcompleted="2019-04-08T15:30:58.827" lastattention="1900-01-01T00:00:00.827" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284178892" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2da9b5468" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4300" ownerId="284174799" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:25:26.760" XDES="0x20d4683b0" lockMode="IX" schedulerid="3" kpid="5664" status="suspended" spid="97" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.847" lastbatchcompleted="2019-04-08T15:30:58.847" lastattention="1900-01-01T00:00:00.847" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284174799" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2efac7468" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4394" ownerId="284192570" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:28:49.180" XDES="0x184e789f0" lockMode="IX" schedulerid="4" kpid="5348" status="suspended" spid="98" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.753" lastbatchcompleted="2019-04-08T15:30:58.753" lastattention="1900-01-01T00:00:00.753" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284192570" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2efac7848" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4409" ownerId="284178168" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:26:23.063" XDES="0x2420aab80" lockMode="IX" schedulerid="4" kpid="4572" status="suspended" spid="68" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.740" lastbatchcompleted="2019-04-08T15:30:58.737" lastattention="1900-01-01T00:00:00.737" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284178168" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process><process id="process2efac7c28" taskpriority="0" logused="0" waitresource="OBJECT: 11:1142295129:0 " waittime="4413" ownerId="284177493" transactionname="implicit_transaction" lasttranstarted="2019-04-08T15:26:12.160" XDES="0xab9103b0" lockMode="IX" schedulerid="4" kpid="2448" status="suspended" spid="52" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2019-04-08T15:30:58.733" lastbatchcompleted="2019-04-08T15:30:58.733" lastattention="1900-01-01T00:00:00.733" clientapp="jTDS" hostname="APPNAME" hostpid="123" loginname="IRB_APP_USER" isolationlevel="repeatable read (3)" xactid="284177493" currentdb="11" currentdbname="Database_Name" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128058"><executionStack><frame procname="adhoc" line="1" stmtstart="46" stmtend="180" sqlhandle="0x02000000b6b6e728e6bf289c908196a1f4e56b8892a5eab10000000000000000000000000000000000000000">
unknown    </frame></executionStack><inputbuf>
(@P0 bigint,@P1 bigint)update Table_Name set STATUS_ID= @P0  where id= @P1    </inputbuf></process></process-list><resource-list><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2f6d828c8" mode="S"/><owner id="process2da9b5468" mode="S"/><owner id="process2f6d828c8" mode="IX" requestType="convert"/><owner id="process2da9b5468" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2ff017c28" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d828c8" mode="S"/><owner id="process2da9b5468" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2f6d828c8" mode="IX" requestType="convert"/><owner id="process2da9b5468" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2f1538108" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d828c8" mode="S"/><owner id="process2da9b5468" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2f6d828c8" mode="IX" requestType="convert"/><owner id="process2da9b5468" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2f618d088" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f618d088" mode="S"/><owner id="process2da9b5468" mode="S"/><owner id="process2f618d088" mode="IX" requestType="convert"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2da9b5468" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2f6d828c8" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f618d088" mode="S"/><owner id="process2da9b5468" mode="S"/><owner id="process2f618d088" mode="IX" requestType="convert"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2da9b5468" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2f6d83848" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d83848" mode="S"/><owner id="process2efac7848" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2efac7848" mode="IX" requestType="convert"/><owner id="process2f6d83848" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2da9b5468" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d83848" mode="S"/><owner id="process2efac7848" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2efac7848" mode="IX" requestType="convert"/><owner id="process2f6d83848" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2efac7468" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d83848" mode="S"/><owner id="process2efac7468" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2efac7468" mode="IX" requestType="convert"/><owner id="process2f6d83848" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2efac7848" mode="IX" requestType="convert"/></waiter-list></objectlock><objectlock lockPartition="0" objid="1142295129" subresource="FULL" dbid="11" objectname="Database_Name.Schema_Name.Table_Name" id="lock2149d8800" mode="S" associatedObjectId="1142295129"><owner-list><owner id="process2ff017c28" mode="S"/><owner id="process2f6d83848" mode="S"/><owner id="process2efac7468" mode="S"/><owner id="process2ff017c28" mode="IX" requestType="convert"/><owner id="process2efac7468" mode="IX" requestType="convert"/><owner id="process2f6d83848" mode="IX" requestType="convert"/></owner-list><waiter-list><waiter id="process2efac7c28" mode="IX" requestType="convert"/></waiter-list></objectlock></resource-list></deadlock>

隔离级别设置为数据库级别的已提交读快照。

当我在哨兵一号计划资源管理器中打开这个死锁图时，它很吓人。

死锁图哨兵计划浏览器

版本：Microsoft SQL Server 2014 (SP3) (KB4022619) - 12.0.6024.0 (X64) Sep 7 2018 01:37:51 版权所有 (c) Microsoft Corporation Enterprise Edition (64-bit) o​​n Windows NT 6.3 (Build 14393:) (管理程序）

sql-server deadlock

3 个回答

  1. 这显然是隔离级别、锁升级和许多会话的错误组合，每个会话在同一事务中发出多个查询。

    使用计划资源管理器打开死锁文件，如果您展开服务员/所有者列表，您会看到他们都在尝试访问相同的资源（可能是整个表）：

    在此处输入图像描述

    还有一个稍微不那么可怕的方法是优化布局并使用强制：

    在此处输入图像描述

    如果你重演死锁（我在这里写过这个功能，早在我还是技术 PM 的时候），你会看到所有这些不同的会话在相对较长的时间内保持他们的交易打开（5 分钟以上，虽然这很疯狂动画真的隐藏了这一点），并间歇性地发出多个查询。您需要大幅减少在这些事务中花费的时间（或完全摆脱它们），将针对不同参数值的多个查询合并为单个时间点查询，构建更好的索引，以免升级发生，停止强制可重复读取，创建聚集索引（如果我正确读取资源描述符，那是堆！？），或以上所有。

    • 12
  2. Best Answer

    您的默认隔离级别可能是 Read Committed Snapshot，但您的应用程序设置的隔离级别 =repeatable read (3)

    对于死锁中的所有更新语句，这些是隔离级别： 

    isolationlevel="repeatable read (3)"

    这是使用以下命令在连接级别完成的：

    SET TRANSACTION ISOLATION LEVEL REPEATABLE READ

    可重复读取 SQL Server 隔离级别可防止脏读取和不可重复读取。它是通过在事务中的每个语句读取的所有数据上放置共享锁来实现的，并且所有锁都被持有直到事务完成。因此其他事务无法修改当前事务已读取的数据。但是，它不会阻止其他事务将新行插入到当前事务中已选择的表中 A part of the explanation on repeatable read here

    事务相互阻塞，在可重复读隔离级别下的锁升级可能会导致阻塞，并且作为阻塞的副产品，死锁。

    等待资源的阻塞查询：

    waitresource="OBJECT: 11:1142295129:0 "

    几个进程在整个对象上都有共享锁：

    <owner id="process2ff017c28" mode="S"/><owner id="process2f6d828c8" mode="S"/><owner id="process2da9b5468" mode="S"/>

    并且这些相同的进程对这些对象有几个意图排他锁

     <owner id="process2f6d828c8" mode="IX" requestType="convert"/>

    而 requestType="convert"解释说进程正在尝试将共享锁转换为 IX 锁。

    正如@David Browne - Microsoft解释的那样：

    在可重复读取中，与挂起的 IX 锁冲突的对象级 S 锁可能已在事务中的较早查询中获得。

    这意味着一个合理的解释是所有这些事务都试图将它们自己的共享锁（例如，由于先前的选择）转换为排他锁（更新语句）。由于处于可重复读隔离级别，他们不想放弃他们的锁，从而导致死锁。

    你能做什么

    您应该联系应用程序团队/供应商，看看这是否是必要的邪恶，因为阻塞将更加普遍。

    在检查隔离级别之后，您应该考虑通过添加索引来加速事务中的查询。

    • 10

  3. 您的 XML 图中的另一个问题是您似乎打开了“implicit_transactions”：

    交易名称=“隐式交易”

    如果应用程序没有明确关闭事务，这也可能导致阻塞。这可以在连接级别设置，也可以通过SET IMPLICIT TRANSACTIONS ON显式调用来设置。

    看看这些时间：

    计划资源管理器死锁图的屏幕截图

    您有在 15:25:26 开始的事务在 15:30:58 仍在运行。五分钟通常对于持有锁来说太长了——这是阻塞和死锁的秘诀。这似乎是一个潜在的意外开放延迟交易。

    如果您对应用程序的连接字符串有任何控制权，请确认他们没有打开此设置。另外，请仔细检查这不是在服务器级别设置的sp_configure 'user options（有关更多详细信息，请参见此处）。

    • 10

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