SQL Server 環形緩衝區（Ring Buffer） -- RING_BUFFER_EXCEPTION 跟蹤異常
動態管理視圖sys.dm_os_ring_buffers使得實時定位問題更加容易。環形緩衝包含大量的在服務器上發生的事件。當前，我正碰到鎖請求超時問題。根據SQL Server Profiler跟蹤捕獲，發現服務器收到大量如下信息：
Lock request time out period exceeded.
我們找到了語句並修改，來阻止所請求超時的發生。現在服務器正被監控，我不想運行SQL Server Profiler去跟蹤這個消息的產生。所以，我想用環形緩衝動態管理視圖去監控是否服務器上有進一步的鎖請求超時發生。這使得監控實例更容易。
下面的腳本給出了一個存儲在環形緩衝區中的異常的時間範圍，輸出了大量的發生的異常。
對於SQL Server 2005：
DECLARE @ts_now BIGINT,@dt_max BIGINT, @dt_min BIGINT
SELECT @ts_now = cpu_ticks / CONVERT(FLOAT, cpu_ticks_in_ms) FROM sys.dm_os_sys_info
select @dt_max = MAX(timestamp), @dt_min = MIN(timestamp) from sys.dm_os_ring_buffers WHERE ring_buffer_type = N'RING_BUFFER_EXCEPTION'
select DATEADD(ms, -1 * (@ts_now - @dt_max), GETDATE()) AS MaxTime,
DATEADD(ms, -1 * (@ts_now - @dt_min), GETDATE()) AS MinTime
SELECT record_id,
DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) AS EventTime,y.Error,UserDefined,b.description as NormalizedText
FROM (
SELECT
record.value('(./Record/@id)[1]', 'int') AS record_id,
record.value('(./Record/Exception/Error)[1]', 'int') AS Error,
record.value('(./Record/Exception/UserDefined)[1]', 'int') AS UserDefined,TIMESTAMP
FROM (
SELECT TIMESTAMP, CONVERT(XML, record) AS record
FROM sys.dm_os_ring_buffers
WHERE ring_buffer_type = N'RING_BUFFER_EXCEPTION'
AND record LIKE '% %') AS x) AS y
INNER JOIN sys.sysmessages b
on y.Error = b.error
WHERE b.msglangid = 1033 and y.Error = 1222 -- Change the message number to the message number that you want to monitor
ORDER BY record_id DESC
對於SQL Server 2008：
DECLARE @ts_now BIGINT,@dt_max BIGINT, @dt_min BIGINT
SELECT @ts_now = cpu_ticks/(cpu_ticks/ms_ticks) FROM sys.dm_os_sys_info
select @dt_max = MAX(timestamp), @dt_min = MIN(timestamp) from sys.dm_os_ring_buffers WHERE ring_buffer_type = N'RING_BUFFER_EXCEPTION'
select DATEADD(ms, -1 * (@ts_now - @dt_max), GETDATE()) AS MaxTime,
DATEADD(ms, -1 * (@ts_now - @dt_min), GETDATE()) AS MinTime
SELECT record_id,
DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) AS EventTime,Error,UserDefined,text as NormalizedText
FROM (
SELECT
record.value('(./Record/@id)[1]', 'int') AS record_id,
record.value('(./Record/Exception/Error)[1]', 'int') AS Error,
record.value('(./Record/Exception/UserDefined)[1]', 'int') AS UserDefined,TIMESTAMP
FROM (
SELECT TIMESTAMP, CONVERT(XML, record) AS record
FROM sys.dm_os_ring_buffers
WHERE ring_buffer_type = N'RING_BUFFER_EXCEPTION'
AND record LIKE '% %') AS x) AS y
INNER JOIN sys.messages b
on y.Error = b.message_id
WHERE b.language_id = 1033 and y.Error = 1222 -- Change the message number to the message number that you want to monitor
ORDER BY record_id DESC
