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Accepted
crokusek
Asked: 2017-03-10 19:55:05 +0800 CST

为死锁扩展事件读取 system_health event_file 而不是 ring_buffer

  • 772

我目前正在使用这场灾难通过读取system_health扩展事件环形缓冲区来定位最近的死锁。

select top 2000000000
      XEvent.value('@timestamp', 'datetime2(3)') as CreationDateUtc,
      --
      -- Extract the <deadlock>...</deadlock> tag from within the event
      -- Todo: Surely there is a better (xml) way to do this.
      --
      substring(convert(varchar(max), XEvent.query('.')), 
          -- start
          patindex('%<deadlock%', convert(varchar(max), XEvent.query('.'))),          
          -- end
          patindex('%</deadlock%', convert(varchar(max), XEvent.query('.'))) -
              patindex('%<deadlock%', convert(varchar(max), XEvent.query('.'))) + 11 -- 11 to include for '</deadlock>'
          ) AS XdlFile
 from 
    (
      select cast (target_data as xml) as TargetData
        from sys.dm_xe_session_targets st with (nolock)
        join sys.dm_xe_sessions s with (nolock)
          on s.address = st.event_session_address
       where [name] = 'system_health'
         and st.target_name = N'ring_buffer'
    ) as Data
 cross apply TargetData.nodes('RingBufferTarget/event[@name="xml_deadlock_report"]') AS XEventData (XEvent)
 order by CreationDateUtc desc

它工作正常，但是事件似乎不会持续很长时间（比如 24 小时？）我猜这是它的“环形缓冲区”部分。现在我偶然发现了一个链接，该链接正在读取system_health具有类似信息的“文件”：

select event_data = CONVERT(XML, event_data) 
from sys.fn_xe_file_target_read_file(N'system_health*.xel', NULL, NULL, NULL)
where event_data like '%xml_deadlock%'

该文件是否与环形缓冲区相同，但停留时间更长？使用文件有什么缺点吗？有一些 XML 技能的人想要转换顶级脚本吗？

目标是将 XdlFile 字段复制/粘贴到新文件中，并使用“文件打开”将其直接读入 SSMS 或 Sql Sentry Plan Explorer。

环形缓冲区链接：

https://connect.microsoft.com/SQLServer/feedback/details/754115/xevents-system-health-does-not-catch-all-deadlocks#tabs

https://www.sqlskills.com/blogs/jonathan/why-i-hate-the-ring_buffer-target-in-extended-events/

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

死锁错误未返回死锁 SQL

文件：

https://www.mssqltips.com/sqlservertip/3636/query-data-from-extended-events-in-sql-server/

@@version = Microsoft SQL Server 2012 (SP3-CU5) (KB3180915) - 11.0.6544.0 (X64)

sql-server sql-server-2012

1 个回答

  1. Best Answer

    这似乎有效：

    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 object_name = 'xml_deadlock_report'
) 
select EventData.value('(event/@timestamp)[1]', 'datetime2(7)') as TimeStamp,
       EventData.query('event/data/value/deadlock') as XdlFile
  from XmlDeadlockReports
 order by TimeStamp desc
    • 5

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