Potrzebujesz pomocy w rozwiązywaniu problemów z zakleszczeniem w Sql Server 2005

9

Natrafiam na scenariusz impasu, w którym jedynymi uczestnikami impasu są pojedyncza tabela i pojedyncza procedura składowana, która usuwa się z tej tabeli. Wyciągnąłem ten wniosek na podstawie mojej analizy dziennika błędów SQL w czasie kilku z tych zakleszczeń, wykorzystując poniższy artykuł MSDN jako wskazówkę do rozszyfrowania śladu w dzienniku błędów.

Tabela DEXTable i procedura składowana ClearDEXTableRows są zdefiniowane poniżej. Istnieje inna procedura składowana InsertDEXTableRow, która wstawia wiersze do DEXTable, ale wydaje się, że proc nie wydaje się brać udziału w impasie na podstawie wpisów w dzienniku błędów sql.

DEXTable ma ~ 8,3 miliona wierszy i ma tendencję do stałego wzrostu. Stół respondenta jest również duży i ma tendencję do stałego wzrostu.

Jest dostępny z witryny o dużym natężeniu ruchu ze stronami, które często wywołują kolejno ClearDEXTableRows i InsertDEXTableRow.

Zakleszczenie występowało od 0 do 9 razy dziennie przez ostatnie 10 dni.

Włączyłem śledzenie SQL dla 1222 (używając DBCC TRACEON 1222), a ostatnio włączyłem flagę 1204. Istnieje dobry opis danych wyjściowych dla tych flag w Wykrywanie i kończenie zakleszczeń

Moje pytania to:

Czy ma sens, że tylko jedna procedura przechowywana ClearDEXTableRows jest przyczyną impasu?

Jeśli tak , to czy ktoś może dobrze wyjaśnić, jak to się dzieje, i zalecić sposób jego rozwiązania?
Podejrzewam, że instrukcje DELETE wywołują spór o PK dla DEXTable, który należy często przebudowywać.

Jeśli nie , to jaki dodatkowy ślad powinienem umożliwić, aby głębiej zagłębić się w przyczynę impasu? (Chcę się tutaj nauczyć)

-- Table definition
CREATE TABLE [dbo].[DEXTable](
                [ExportID] [int] NOT NULL,
                [RespondentID] [int] NOT NULL,
                [Exported] [datetime] NOT NULL,
CONSTRAINT [PK_DEXTable] PRIMARY KEY CLUSTERED
(
                [ExportID] ASC,
                [RespondentID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[DEXTable]  WITH CHECK ADD  CONSTRAINT [FK_DEXTable_Exports] FOREIGN KEY([ExportID])
REFERENCES [dbo].[Exports] ([ExportID])
ON DELETE CASCADE
GO

ALTER TABLE [dbo].[DEXTable] CHECK CONSTRAINT [FK_DEXTable_Exports]
GO

ALTER TABLE [dbo].[DEXTable]  WITH CHECK ADD  CONSTRAINT [FK_DEXTable_Respondents] FOREIGN KEY([RespondentID])
REFERENCES [dbo].[Respondents] ([RespondentID])
GO

ALTER TABLE [dbo].[DEXTable] CHECK CONSTRAINT [FK_DEXTable_Respondents]
GO

ALTER TABLE [dbo].[DEXTable] ADD  DEFAULT (getdate()) FOR [Exported]
GO

-- "ClearDEXTableRows"
-- Clear a respondent's export records to trigger re-export.
CREATE PROCEDURE [dbo].[ClearDEXTableRows]
    @RespondentID int
AS
    DELETE DEXTable WITH (ROWLOCK)
    WHERE RespondentID = @RespondentID
GO

-- "InsertDEXTableRow"
-- Insert record noting export run for a particular respondent.
CREATE PROCEDURE [dbo].[InsertDEXTableRow]
    @ExportID int,
    @RespondentID int
AS
    IF NOT EXISTS (SELECT RespondentID FROM DEXTable WHERE ExportID = @ExportID AND RespondentID = @RespondentID)
    BEGIN
      INSERT DEXTable
        (ExportID, RespondentID, Exported)
      VALUES
        (@ExportID, @RespondentID, getdate())
    END
    ELSE
    BEGIN
      UPDATE DEXTable
      SET Exported = getdate()
      WHERE ExportID = @ExportID AND RespondentID = @RespondentID
    END
GO

A oto niektóre wpisy w dzienniku (nie jestem całkowicie pewien, co jest pomocne)

-- Sql error log for one of the recent deadlocks
-- Most recent entries in the log are at the top and go further back in time as you read down

11/17/2011 00:00:58,spid18s,Unknown,This instance of SQL Server has been using a process ID of 1840 since 10/31/2011 7:19:43 PM (local) 11/1/2011 12:19:43 AM (UTC). This is an informational message only; no user action is required.

11/16/2011 20:37:59,spid20s,Unknown,waiter id=process86a6478 mode=U requestType=wait

11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lockd32579f80 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process47eda8 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lockc48e52780 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=processce50ce088 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=locka6ad4e580 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process8691198 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock95f600780 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process478da8 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock955c98200 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process700328 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock83fd3b200 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=processffaef8 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock77b633580 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process86a6ef8 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lockdc536d580 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter event=e_waitPipeGetRow type=consumer id=processcd7b1b048
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process717198
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=processffaef8
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process86a6478
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=processdc28aeef8
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=processce50ce088
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process47eda8
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,exchangeEvent id=port80314690 nodeId=3
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process717198 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock68f374980 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process716c58 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock60e8d8a80 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process47f198 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processdc28aeef8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lockb7c7f1c00 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter id=processdc28aeef8 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processac352e9b8 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock7797b6500 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,waiter event=e_waitPipeGetRow type=consumer id=processac352e9b8
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process6d5c18
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process716c58
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process478da8
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process8691198
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process86a6ef8
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process700328
11/16/2011 20:37:59,spid20s,Unknown,owner event=e_waitNone type=producer id=process47f198
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,exchangeEvent id=port80315870 nodeId=3
11/16/2011 20:37:59,spid20s,Unknown,waiter id=process6d5c18 mode=U requestType=wait
11/16/2011 20:37:59,spid20s,Unknown,waiter-list
11/16/2011 20:37:59,spid20s,Unknown,owner id=processcd7b1b048 mode=U
11/16/2011 20:37:59,spid20s,Unknown,owner-list
11/16/2011 20:37:59,spid20s,Unknown,keylock hobtid=72057594060931072 dbid=5 objectname=MyServer_Database.dbo.DEXTable indexname=PK_DEXTable id=lock46a62fe00 mode=U associatedObjectId=72057594060931072
11/16/2011 20:37:59,spid20s,Unknown,resource-list
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=processdc28aeef8 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (d600a7d4a467) waittime=4836 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0xce4278410 lockMode=U schedulerid=8 kpid=15756 status=suspended spid=157 sbid=0 ecid=6 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=processce50ce088 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (d1007416f809) waittime=5538 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0x946b46d30 lockMode=U schedulerid=4 kpid=20396 status=suspended spid=157 sbid=0 ecid=3 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,Proc [Database Id = 5 Object Id = 957962489]
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=processcd7b1b048 taskpriority=0 logused=20003 waittime=4118 schedulerid=3 kpid=13252 status=suspended spid=157 sbid=0 ecid=0 priority=0 transcount=2 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 loginname=IIS APPPOOL\MyServer_Database isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,Proc [Database Id = 5 Object Id = 957962489]
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=processac352e9b8 taskpriority=0 logused=20003 waittime=4071 schedulerid=10 kpid=20384 status=suspended spid=147 sbid=0 ecid=0 priority=0 transcount=2 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 loginname=IIS APPPOOL\MyServer_Database isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process86a6ef8 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (ab0001e10f4e) waittime=6099 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0xdb9b53cc0 lockMode=U schedulerid=11 kpid=17448 status=suspended spid=147 sbid=0 ecid=4 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process86a6478 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (7500c3691103) waittime=6099 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0xdb9b53a80 lockMode=U schedulerid=11 kpid=19324 status=suspended spid=157 sbid=0 ecid=7 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process8691198 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (d20082032104) waittime=6052 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0xabdc20870 lockMode=U schedulerid=10 kpid=24760 status=suspended spid=147 sbid=0 ecid=7 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=processffaef8 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (f900d9903a2a) waittime=6099 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0xd9f26e080 lockMode=U schedulerid=9 kpid=16712 status=suspended spid=157 sbid=0 ecid=8 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process717198 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (4700497f7879) waittime=5959 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0x8006dcc0 lockMode=U schedulerid=6 kpid=7420 status=suspended spid=157 sbid=0 ecid=12 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process716c58 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (5a00f098709d) waittime=5928 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0x6c020d880 lockMode=U schedulerid=6 kpid=17856 status=suspended spid=147 sbid=0 ecid=11 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process700328 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (51003376bf57) waittime=6099 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0x92beba3d0 lockMode=U schedulerid=5 kpid=7004 status=suspended spid=147 sbid=0 ecid=3 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process6d5c18 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (150048fb6c35) waittime=5803 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0xdbadb2560 lockMode=U schedulerid=3 kpid=3824 status=suspended spid=147 sbid=0 ecid=12 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process47f198 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (4700c2a10b35) waittime=6037 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0x6c2da4080 lockMode=U schedulerid=2 kpid=8564 status=suspended spid=147 sbid=0 ecid=1 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process47eda8 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (2a004ee465b9) waittime=6099 ownerId=299785428 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.820 XDES=0x6c2da4870 lockMode=U schedulerid=2 kpid=24652 status=suspended spid=157 sbid=0 ecid=1 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.820 lastbatchcompleted=2011-11-16T20:37:53.807 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785428 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,inputbuf
11/16/2011 20:37:59,spid20s,Unknown,WHERE RespondentID = @RespondentID
11/16/2011 20:37:59,spid20s,Unknown,DELETE DEXTable WITH (ROWLOCK)
11/16/2011 20:37:59,spid20s,Unknown,frame procname=MyServer_Database.dbo.ClearDEXTableRows line=7 stmtstart=334 sqlhandle=0x03000500f958193991f66b01a29e00000100000000000000
11/16/2011 20:37:59,spid20s,Unknown,executionStack
11/16/2011 20:37:59,spid20s,Unknown,process id=process478da8 taskpriority=0 logused=0 waitresource=KEY: 5:72057594060931072 (1400c876e809) waittime=5709 ownerId=299785445 transactionname=DELETE lasttranstarted=2011-11-16T20:37:53.823 XDES=0x857272d30 lockMode=U schedulerid=1 kpid=7804 status=suspended spid=147 sbid=0 ecid=9 priority=0 transcount=0 lastbatchstarted=2011-11-16T20:37:53.823 lastbatchcompleted=2011-11-16T20:37:53.810 clientapp=.Net SqlClient Data Provider hostname=309389-DB13 hostpid=6536 isolationlevel=read committed (2) xactid=299785445 currentdb=5 lockTimeout=4294967295 clientoption1=671088672 clientoption2=128056
11/16/2011 20:37:59,spid20s,Unknown,process-list
11/16/2011 20:37:59,spid20s,Unknown,deadlock victim=processdc28aeef8
11/16/2011 20:37:59,spid20s,Unknown,deadlock-list
11/16/2011 16:40:12,spid83,Unknown,DBCC TRACEON 1222<c/> server process ID (SPID) 83. This is an informational message only; no user action is required.
sql-server-2005  primary-key  deadlock  logs  upsert 
— BobbyR-1of4
źródło
2
Czy możesz się upewnić, że flaga śledzenia 1204 jest globalnie włączona „dbcc traceon (1204, -1)” i publikuje przechwytywanie po kolejnym impasie.
— mrdenny
Dziękujemy wszystkim za szybką i pomocną opinię! Jest to bardzo mile widziane. Włączyłem flagę śledzenia 1204 i idę do przodu po odwróceniu zamówienia PK do (RespondentID, ExportID) i usunięciu podpowiedzi USUŃ Z (ROWLOCK). Czy chodzi o dodanie podpowiedzi MAXDOP 1, czy masz na myśli procedurę InsertDEXTableRow lub ClearDEXTableRows? A jeśli powinien przejść do procedury InsertDEXTableRow, czy uważasz, że będzie bardziej skuteczny w jednym bloku UPSERT w porównaniu do drugiego? (zasugerowano 3 alternatywy UPSERT).
— BobbyR-1of4
Ponownie dziękuję za wspaniałą opinię na temat mojego postu: wykonałem następujące kroki: • Odwróciłem PK w tabeli DEXTable (najpierw RespondentID, a następnie ExportID), aby uniknąć skanowania tabeli. • Usunięto niepotrzebną wskazówkę dotyczącą ROWLOCK w procedurze ClearDEXTableRows. • W procedurze InsertDEXTableRow użyto bezpiecznego wzorca (aktualizacji lub wstawiania) bezpiecznego współbieżności (opcja 1 zalecana przez Mark Storey-Smith).
— BobbyR-1 z 4
ciąg dalszy ... Przed wprowadzeniem zmian potwierdziłem, że moja aplikacja internetowa nie wysyła żadnych zapytań do tabeli DEXTable z jedynie ExportID w klauzuli where lub INNER JOIN bez uprzedniego filtrowania według RespondentID. Przeszukałem zarówno bazę danych serwera SQL, jak i bazę kodu (dla referencji linq2sql itp.). Kolejność odwołań do kolumn w klauzuli WHERE nie powinna mieć znaczenia (tj. GDZIE ExportID = at-ExportID AND RespondentID = at-RespondentID kontra WHERE RespondentID = at-RespondentID AND ExportID = at-ExportID), w oparciu o informacje, które znalazłem w Google że.
— BobbyR-1of4
ciąg dalszy ... Potwierdziłem, że plany wykonania sql zmieniły się ze skanów na poszukiwania po odwróceniu kolejności kolumn FK w PK. Nie skorzystałem z sugestii MAXDOP 1, ponieważ nie jestem pewien, która procedura powinna jej użyć (ClearDEXTableRows lub InsertDEXTableRow) i czy nadal ma to sens biorąc pod uwagę wybraną opcję (wspomnianą powyżej).
— BobbyR-1of4

Odpowiedzi:

7

Wyskakują trzy rzeczy:

  1. Twoje DELETE znajduje się w drugiej kolumnie (RespondentID) bieżącego PK, co oznacza skanowanie, a nie wyszukiwanie.

  2. Bezcelowa wskazówka ROWLOCK

  3. Twój wzorzec „UPSERT” nie jest bezpieczny dla współbieżności. Test na istnienie może przejść do 2 nakładających się (w czasie) równoczesnych wątków, co powoduje błąd.

Naprawić

  1. Odwróć swoje zamówienie PK w DEXTable na (RespondentID, ExportID). Lub dodaj osobny indeks do samego RespondentID. Osobiście prawdopodobnie odwróciłbym zamówienie PK.

  2. Usuń wskazówkę dotyczącą ROWLOCK. Jeśli kontynuuje się po sugerowanych tutaj zmianach indeksu i UPSERT, spróbuj UPDLOCK, ale tylko po sprawdzeniu równoległości

  3. Sprawdź równoległość w planie: spróbuj MAXDOP 1, aby ograniczyć. Wypróbuj to przed UPDLOCK

  4. Użyj wzorca UPSERT „JFDI”. Oznacza to, że INSERT i tak sprawdzi unikalność, więc po prostu INSERT, jeśli się nie powiedzie, UPDATE.

W przypadku SQL Server 2005 (użyjesz MERGE na SQL Server 2008+)

BEGIN TRY

    BEGIN TRY
        INSERT DEXTable (ExportID, RespondentID, Exported)
        VALUES (@ExportID, @RespondentID, getdate())
    END TRY
    BEGIN CATCH
        IF ERROR_NUMBER() = 2627
            UPDATE DEXTable
            SET Exported = getdate()
            WHERE ExportID = @ExportID AND RespondentID = @RespondentID
        ELSE
        BEGIN
           ..process real error
           RAISERROR (...)
        END
    END CATCH

END TRY
BEGIN CATCH
    ..process
    RAISERROR (...)
END CATCH

Wreszcie MSDN zaleca wychwycenie błędów zakleszczenia i ponowną próbę po stronie klienta. Powinno to stanowić część warstwy dostępu do danych, która obsługuje wszystkie połączenia SQL.

— gbn
źródło
5

+1 za wyjaśnienie prawdopodobnej przyczyny @ gbn, ale nie jestem fanem sugerowanego wzoru INSERT / UPDATE, chyba że aktualizacja jest naprawdę wyjątkowym przypadkiem (tj. 99,99% czasu, w którym wstawka występuje). Moim preferowanym podejściem zawsze było:

BEGIN TRANSACTION

UPDATE DEXTable WITH (UPDLOCK, HOLDLOCK)
SET Exported = getdate()
WHERE ExportID = @ExportID AND RespondentID = @RespondentID

IF (@@ROWCOUNT = 0)
BEGIN
    INSERT DEXTable (ExportID, RespondentID, Exported)
    VALUES (@ExportID, @RespondentID, getdate())
END

COMMIT TRANSACTION

Możesz również złagodzić impas, dodając wskazówki do bieżącego zapytania:

BEGIN TRANSACTION

IF NOT EXISTS (SELECT RespondentID FROM DEXTable WITH (UPDLOCK, HOLDLOCK) WHERE ExportID = @ExportID AND RespondentID = @RespondentID)
    BEGIN
      INSERT DEXTable
        (ExportID, RespondentID, Exported)
      VALUES
        (@ExportID, @RespondentID, getdate())
    END
    ELSE
    BEGIN
      UPDATE DEXTable
      SET Exported = getdate()
      WHERE ExportID = @ExportID AND RespondentID = @RespondentID
    END

COMMIT TRANSACTION
— Mark Storey-Smith
źródło
2

Bez dalszych informacji o impasie zgaduję tutaj, ale ...

W kolumnie, której używasz, nie ma indeksu znajdź wiersze do usunięcia. Oznacza to za każdym razem skanowanie indeksu klastrowego, co oznacza wiele blokad po rozpoczęciu usuwania. Mimo że masz w niej opcję Z (ROWLOCK), nadal muszą być na stole zablokowane schematy, aby mieć pewność, że nic się nie dzieje.

Spróbuj dodać indeks do kolumny RespondentID i sprawdź, czy to rozwiąże problem. Spojrzenie na plan wykonania przed utworzeniem tego indeksu i po nim powinno dać pewne wskazówki co do rozwiązania problemu.

— mrdenny
źródło
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