我目前的.NET应用程序中的MSSQL数据库有时会出现死锁。我使用存储过程将数据添加到名为“DATA_CONT”的表中。此外,还有一个定期任务从此表中删除旧数据。有时在同时执行插入和删除过程时会出现死锁。
表DATA_CONT拥有一个包含外键CID(uniqueidentifier)和ResultDate(datetime2(3))的聚集索引。
这是MS SQL的死锁xml图:
<deadlock>
<victim-list>
<victimProcess id="process6137528c8" />
</victim-list>
<process-list>
<process id="process6137528c8" taskpriority="5" logused="0" waitresource="KEY: 7:72057594046185472 (0d3d2e12b103)" waittime="1637" ownerId="9357686" transactionname="user_transaction" lasttranstarted="2018-11-12T11:20:55.167" XDES="0x61e4703b0" lockMode="RangeS-U" schedulerid="7" kpid="14644" status="suspended" spid="53" sbid="0" ecid="0" priority="-5" trancount="2" lastbatchstarted="2018-11-12T11:20:55.167" lastbatchcompleted="2018-11-12T11:20:55.167" lastattention="1900-01-01T00:00:00.167" clientapp=".Net SqlClient Data Provider" hostname="FE-Z13YL" hostpid="24056" loginname="DE\afr3fe" isolationlevel="serializable (4)" xactid="9357686" currentdb="7" lockTimeout="1800" clientoption1="673316896" clientoption2="128056">
<executionStack>
<frame procname="MyDatabase.dbo.Proc_DeleteDataCont" line="12" stmtstart="708" stmtend="954" sqlhandle="0x03000700f2a6e25b72b58a0092a9000001000000000000000000000000000000000000000000000000000000">
Delete From
[DATA_CONT]
WHERE
CID = @p_CID AND
(@p_DeleteOlderThan IS NULL OR ResultDate < @p_DeleteOlderThan </frame>
</executionStack>
<inputbuf>
Proc [Database Id = 7 Object Id = 1541580530] </inputbuf>
</process>
<process id="process658113468" taskpriority="0" logused="592" waitresource="KEY: 7:72057594046185472 (ae5185f64403)" waittime="1711" ownerId="9357687" transactionname="user_transaction" lasttranstarted="2018-11-12T11:20:55.170" XDES="0x65cd77000" lockMode="RangeI-N" schedulerid="6" kpid="21008" status="suspended" spid="52" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2018-11-12T11:20:55.170" lastbatchcompleted="2018-11-12T11:20:55.170" lastattention="1900-01-01T00:00:00.170" clientapp=".Net SqlClient Data Provider" hostname="FE-Z13YL" hostpid="24056" loginname="DE\afr3fe" isolationlevel="serializable (4)" xactid="9357687" currentdb="7" lockTimeout="4294967295" clientoption1="673316896" clientoption2="128056">
<executionStack>
<frame procname="MyDatabase.dbo.Proc_AddDataCont" line="8" stmtstart="266" stmtend="598" sqlhandle="0x030007005654c5593a84070188a9000001000000000000000000000000000000000000000000000000000000">
INSERT INTO [DATA_CONT] SELECT CID, Value, LocationData, ResultDate, GETUTCDATE() FROM @p_DataContLis </frame>
</executionStack>
<inputbuf>
Proc [Database Id = 7 Object Id = 1506104406] </inputbuf>
</process>
</process-list>
<resource-list>
<keylock hobtid="72057594046185472" dbid="7" objectname="MyDatabase.dbo.DATA_CONT" indexname="IX_DATA_CONT" id="lock620b19a80" mode="X" associatedObjectId="72057594046185472">
<owner-list>
<owner id="process658113468" mode="X" />
</owner-list>
<waiter-list>
<waiter id="process6137528c8" mode="RangeS-U" requestType="wait" />
</waiter-list>
</keylock>
<keylock hobtid="72057594046185472" dbid="7" objectname="MyDatabase.dbo.DATA_CONT" indexname="IX_DATA_CONT" id="lock620b19800" mode="RangeS-U" associatedObjectId="72057594046185472">
<owner-list>
<owner id="process6137528c8" mode="RangeS-U" />
</owner-list>
<waiter-list>
<waiter id="process658113468" mode="RangeI-N" requestType="wait" />
</waiter-list>
</keylock>
</resource-list>
</deadlock>
对我来说,似乎两个锁都被升级了。我该如何避免这种情况?
DEADLOCK_PRIORITY
设置为LOW
,分批小量删除,分配宽松的重试策略并完全忽略此过程中的死锁,仅检查删除是否足够快以保持表格一致。除了您可能采取的其他减少/消除死锁的措施之外,当忽略它们可以解决问题时,通常不可能或不划算完全摆脱它们。(显然,这并非所有死锁都是如此,因为并非所有内容都可以重试--但清理可以)。 - Jeroen Mostert