Besoin d'aide pour résoudre le scénario de blocage de Sql Server 2005

9

Je suis dans un scénario de blocage où les seuls participants au blocage semblent être une seule table et une seule procédure stockée qui supprime de cette table. J'ai tiré cette conclusion sur la base de mon analyse du journal des erreurs sql au moment de plusieurs de ces blocages, en utilisant l'article MSDN ci-dessous comme guide pour déchiffrer la trace dans le journal des erreurs.

La table DEXTable et la procédure stockée ClearDEXTableRows sont définies ci-dessous. Il existe une autre procédure stockée InsertDEXTableRow qui insère des lignes dans DEXTable, mais ce processus ne semble pas être impliqué dans le blocage basé sur les entrées du journal des erreurs SQL.

Le DEXTable contient environ 8,3 millions de lignes et a tendance à croître régulièrement. Le tableau des répondants est également volumineux et a tendance à augmenter régulièrement.

Il est accessible à partir d'un site Web à fort trafic avec des pages qui appellent fréquemment ClearDEXTableRows et InsertDEXTableRow en succession rapide.

L'impasse s'est produite entre 0 et 9 fois par jour au cours des 10 derniers jours.

J'ai activé la trace sql pour 1222 (en utilisant DBCC TRACEON 1222) et récemment activé le drapeau 1204. Il y a une bonne description de la sortie de ces drapeaux sur la détection et la fin des blocages

Mes questions sont:

Est-il logique que seule cette procédure stockée ClearDEXTableRows soit la cause du blocage?

Si oui , quelqu'un peut-il expliquer comment cela peut se produire et recommander un moyen de le corriger?
Je soupçonne que les instructions DELETE provoquent des conflits sur le PK pour DEXTable qui doit être reconstruit fréquemment.

Sinon , quelle trace supplémentaire devrais-je permettre pour approfondir la cause de l'impasse? (Je veux apprendre ici)

-- 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

Et voici quelques entrées du journal (je ne suis pas tout à fait sûr de ce qui est utile)

-- 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
source
2
Pouvez-vous vous assurer que l'indicateur de trace 1204 est activé globalement "dbcc traceon (1204, -1)" et publier cette capture après le prochain blocage.
— mrdenny
Merci à tous pour les commentaires rapides et utiles! C'est très apprécié. J'ai activé l'indicateur de trace 1204 et je vais de l'avant en inversant l'ordre PK vers (RespondentID, ExportID) et en supprimant l'indication DELETE WITH (ROWLOCK). En ce qui concerne l'ajout de l'indication MAXDOP 1, voulez-vous dire dans la procédure InsertDEXTableRow ou ClearDEXTableRows? Et si elle devait entrer dans la procédure InsertDEXTableRow, pensez-vous qu'elle sera plus efficace dans un bloc UPSERT par rapport à un autre? (3 alternatives UPSERT ont été suggérées).
— BobbyR-1of4
Encore une fois, mes remerciements pour les excellents commentaires sur mon message: J'ai poursuivi les étapes suivantes: • Inversé le PK sur la table DEXTable (RépondantID d'abord, puis ExportID) pour éviter les analyses de table. • Suppression d'un indice ROWLOCK inutile dans la procédure ClearDEXTableRows. • Utilisé un modèle upsert sécurisé (mise à jour ou insertion) sécurisé (option 1 recommandé par Mark Storey-Smith) dans la procédure InsertDEXTableRow.
— BobbyR-1 du 4
suite ... Avant d'apporter les modifications, j'ai confirmé que mon application Web n'émettait aucune requête sur la table DEXTable avec uniquement l'ExportID dans la clause where ou INNER JOIN sans premier filtrage par RespondentID. J'ai recherché à la fois la base de données du serveur SQL et la base de code (pour les références linq2sql, etc.). L'ordre des références de colonne dans la clause WHERE ne devrait pas avoir d'importance (c.-à-d. WHERE ExportID = at-ExportID AND RespondentID = at-RespondentID versus WHERE RespondentID = at-RespondentID AND ExportID = at-ExportID), en fonction des informations que j'ai trouvées sur Google cette.
— BobbyR-1of4
suite ... J'ai confirmé que les plans d'exécution sql étaient passés des analyses aux recherches après avoir inversé l'ordre des colonnes FK au sein du PK. Je n'ai pas utilisé la suggestion d'indice MAXDOP 1, car je ne sais pas quelle procédure devrait l'utiliser (ClearDEXTableRows ou InsertDEXTableRow) et si cela a toujours du sens compte tenu de l'option que j'ai choisie (notée ci-dessus).
— BobbyR-1of4

Réponses:

7

Trois choses sautent aux yeux:

  1. Votre SUPPRIMER est sur la 2ème colonne (RespondentID) du PK actuel, ce qui signifie une analyse, pas une recherche.

  2. Indice ROWLOCK inutile

  3. Votre modèle "UPSERT" n'est pas sécurisé pour les accès simultanés. Le test d'existence peut réussir pour 2 threads simultanés qui se chevauchent (dans le temps), ce qui donne une erreur.

Pour réparer

  1. Inversez votre commande PK dans DEXTable à (RespondentID, ExportID). Ou ajoutez un index distinct sur l'intimé seul. Personnellement, j'inverserais probablement l'ordre PK.

  2. Supprimer l'indice ROWLOCK. Si cela continue après les modifications d'index et d'UPSERT suggérées ici, essayez UPDLOCK, mais seulement après avoir vérifié le parallélisme

  3. Vérifiez le parallélisme dans le plan: essayez MAXDOP 1 pour restreindre. Essayez ceci avant UPDLOCK

  4. Utilisez le modèle UPSERT "JFDI". C'est-à-dire que l'INSERT vérifiera l'unicité de toute façon, alors INSÉRER simplement, s'il échoue, puis MISE À JOUR.

Pour SQL Server 2005 (vous utiliseriez MERGE sur 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

Enfin, MSDN vous recommande d'intercepter les erreurs de blocage et de réessayer du côté client. Cela devrait faire partie de votre couche d'accès aux données qui gère tous vos appels SQL.

— gbn
source
5

+1 pour l'explication de @ gbn sur la cause probable, mais je ne suis pas fan du modèle INSERT / UPDATE suggéré, sauf si une mise à jour est vraiment le cas exceptionnel (c'est-à-dire 99,99% du temps où un insert se produit). Mon approche préférée a toujours été:

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

Vous pouvez également atténuer l'impasse en ajoutant des conseils à votre requête actuelle:

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
source
2

Sans plus d'informations sur l'impasse, je devine juste ici, mais ...

Il n'y a pas d'index sur la colonne que vous utilisez pour trouver les lignes à supprimer. Cela signifie une analyse d'index en cluster à chaque fois, ce qui signifie beaucoup de verrous au début de la suppression. Même si vous avez AVEC (ROWLOCK), il doit toujours y avoir des verrous de schéma sur la table pour vous assurer que rien ne se passe.

Essayez d'ajouter un index sur la colonne RespondentID et voyez si cela résout le problème. L'examen du plan d'exécution avant et après la création de cet index devrait également donner une indication du problème à résoudre.

— mrdenny
source
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