Pour distinguer ces blocages non critiques "à résolution automatique par déversement" des blocages plus importants, une sémantique de recherche peut être appliquée à la structure Xdl.
Le SP suivant ne fonctionnera pas hors de la boîte car il dépend de ufn_ExtractSubstringsByPattern () mais cette méthode peut être remplacée par quelque chose qui retourne directement le nombre distinct.
ALTER view [Common].[DeadLockRecentHistoryView]
as
/*---------------------------------------------------------------------------------------------------------------------
Purpose: List history of recent deadlock events
Warning: The XML processing may hit a recursion limit (100), suggest using "option (maxrecursion 10000)".
Xdl File:
The SSMS deadlock file format .XDL format (xml) has changed with later versions of SQL Server. This version tested with 2012.
Ring Buffer issues:
https://connect.microsoft.com/SQLServer/feedback/details/754115/xevents-system-health-does-not-catch-all-deadlocks
https://www.sqlskills.com/blogs/jonathan/why-i-hate-the-ring_buffer-target-in-extended-events/
Links:
http://www.sqlskills.com/blogs/jonathan/multi-victim-deadlocks/
https://www.sqlskills.com/blogs/jonathan/graphically-viewing-extended-events-deadlock-graphs/
http://www.mssqltips.com/sqlservertip/1234/capturing-sql-server-deadlock-information-in-xml-format/
http://blogs.msdn.com/b/sqldatabasetalk/archive/2013/05/01/tracking-down-deadlocks-in-sql-database.aspx
http://dba.stackexchange.com/questions/10644/deadlock-error-isnt-returning-the-deadlock-sql/10646#10646
Modified By Description
---------- ----------- ------------------------------------------------------------------------------------------
2014.10.29 crokusek From Internet, http://stackoverflow.com/questions/19817951
2015.05.05 crokusek Improve so that the output is consumable by SSMS 2012 as "Open .xdl file"
2015.05.22 crokusek Remove special character for the cast to Xml (like '&')
2017.08.03 crokusek Abandon ring-buffer approach and use event log files. Filter out internal deadlocks.
2018.07.16 crokusek Added field(s) like ProbablyHandledBySpill to help identify non-critical deadlocks.
---------------------------------------------------------------------------------------------------------------------*/
with XmlDeadlockReports as
(
select convert(xml, event_data) as EventData
from sys.fn_xe_file_target_read_file(N'system_health*.xel', NULL, NULL, NULL)
where substring(event_data, 1, 50) like '%"xml_deadlock_report"%'
)
select top 10000
EventData.value('(event/@timestamp)[1]', 'datetime2(7)') as CreatedUtc,
--(select TimePst from Common.ufn_ConvertUtcToPst(EventData.value('(event/@timestamp)[1]', 'datetime2(7)'))) as CreatedPst,
DistinctSpidCount,
HasExchangeEvent,
IsVictimless,
--
-- If the deadlock contains Exchange Events and lists no victims, it probably occurred
-- during execution of a single query that contained parallellism but got stuck due to
-- ordering issues. /dba/197779
--
-- These will not raise an exception to the caller and will complete by spilling to tempdb
-- however they may run much slower than they would without the spill(s).
--
convert(bit, iif(DistinctSpidCount = 1 and HasExchangeEvent = 1 and IsVictimless = 1, 1, 0)) as ProbablyHandledBySpill,
len(et.XdlFileText) as LenXdlFile,
eddl.XdlFile as XdlFile
from XmlDeadlockReports
cross apply
(
select eventData.query('event/data/value/deadlock') as XdlFile
) eddl
cross apply
(
select convert(nvarchar(max), eddl.XdlFile) as XdlFileText
) as et
cross apply
(
select count(distinct Match) as DistinctSpidCount
from common.ufn_ExtractSubstringsByPattern(et.XdlFileText, 'spid="%%"')
) spids
cross apply
(
select convert(bit, iif(charindex('<exchangeEvent', et.XdlFileText) > 0, 1, 0)) as HasExchangeEvent,
--
convert(bit, iif( charindex('<victim-list>', et.XdlFileText) = 0
and charindex('<victim-list/>', et.XdlFileText) > 0, 1, 0)) as IsVictimless
) as flags
order by CreatedUtc desc
GO
