DMV {dm_os_ring_buffers} - Queries to help pinpoint current Issues / usual usage patterns

Posted by NeilHambly on SQL Blogcasts See other posts from SQL Blogcasts or by NeilHambly
Published on Thu, 18 Mar 2010 13:47:00 GMT Indexed on 2010/03/18 14:41 UTC
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I'm been running some queries (below) to help me identify when I have had time-sensitive performance issues around Memory/CPU, I didn't want to load up additional overhead to the system (unless absolutely neccessary) using traces or profiler  - naturally we have various methods to do this Perfmon counters, DBCC, DMVs etc..

One quick way I like is to run a few DMV queries (normally back in seconds) to help me find those RECENT specific time periods when the system has been substantially changed in some way using, this is using the DMV dm_os_ring_buffers

This one helps me identify when I'm expericing Timeout Errors (1222).. modiy code to look for other error as highlight below

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       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 ORDER BY record_id DESC

Sample Output

record_id EventTime Error UserDefined NormalizedText
15199195 18/03/2010 14:00 1222 0 Lock request time out period exceeded.
15199194 18/03/2010 14:00 1222 0 Lock request time out period exceeded.
15199193 18/03/2010 14:00 1222 0 Lock request time out period exceeded.
15199192 18/03/2010 14:00 1222 0 Lock request time out period exceeded.
15199191 18/03/2010 14:00 1222 0 Lock request time out period exceeded.

 This one helps me identify when I have Unusally High Processing (> 50%) or # Page-Faults

SELECT record.value('(./Record/@id)[1]', 'int') AS record_id,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int')              AS SystemIdle,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]', 'int')      AS SQLProcessUtilization,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/UserModeTime)[1]', 'bigint')         AS UserModeTime,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/KernelModeTime)[1]', 'bigint')       AS KernelModeTime,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/PageFaults)[1]', 'bigint')           AS PageFaults,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/WorkingSetDelta)[1]', 'bigint')      AS WorkingSetDelta,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/MemoryUtilization)[1]', 'int')       AS MemoryUtilization,TIMESTAMPFROM (        SELECT TIMESTAMP, CONVERT(XML, record) AS record         FROM sys.dm_os_ring_buffers         WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR'        AND record LIKE '% %'

        ) AS x

Example: Showing entries > 50% SQL CPU

record_id SystemIdle SQLProcessUtilization UserModeTime KernelModeTime PageFaults WorkingSetDelta MemoryUtilization TIMESTAMP
111916 66 29 36718750 1374843750 21333 -40960 100 7991061289
111917 54 41 50156250 1954062500 26914 -28672 100 7991121290
111918 57 39 42968750 1838437500 30096 20480 100 7991181290
111919 41 53 43906250 2530156250 22088 -4096 100 7991241307
111920 48 45 40937500 2124062500 26395 8192 100 7991301310
111921 52 43 35625000 2052812500 21996 155648 100 7991361311
111922 40 55 36875000 2637343750 33355 -262144 100 7991421311
111923 36 58 44843750 2786562500 47019 28672 100 7991481311
111924 31 64 53437500 3046562500 31027 61440 100 7991541314
111925 36 57 43906250 2711250000 37074 -8192 100 7991601317
111926 52 43 43437500 2060156250 29176 20480 100 7991661318
111927 71 24 33750000 1141250000 14478 16384 100 7991721320
111928 71 23 34531250 1116250000 12711 -20480 100 7991781320
111929 53 36 46562500 1714062500 26684 200704 100 7991841323

Finally one to provide some understanding of the level of memory state changes that are ocuring

SELECT record.value('(./Record/@id)[1]', 'int')                                                       AS 'record_id',record.value('(./Record/ResourceMonitor/Notification)[1]', 'VARCHAR(100)')                     AS 'ReservedMemory',record.value('(./Record/ResourceMonitor/Indicators)[1]', 'int')                                AS 'Indicators',record.value('(./Record/ResourceMonitor/Effect/@state)[1]', 'VARCHAR(100)')         + ' - ' + record.value('(./Record/ResourceMonitor/Effect/@reversed)[1]', 'VARCHAR(100)')      + ' - ' + record.value('(./Record/ResourceMonitor/Effect)[1]', 'VARCHAR(100)')                           AS 'APPLY-HIGHPM',record.value('(./Record/ResourceMonitor/Effect/@state)[2]', 'VARCHAR(100)')         + ' - ' + record.value('(./Record/ResourceMonitor/Effect/@reversed)[2]', 'VARCHAR(100)')      + ' - ' + record.value('(./Record/ResourceMonitor/Effect)[2]', 'VARCHAR(100)')                           AS 'APPLY-HIGHPM',record.value('(./Record/ResourceMonitor/Effect/@state)[3]', 'VARCHAR(100)')         + ' - ' + record.value('(./Record/ResourceMonitor/Effect/@reversed)[3]', 'VARCHAR(100)')      + ' - ' + record.value('(./Record/ResourceMonitor/Effect)[3]', 'VARCHAR(100)')                           AS 'REVERT_HIGHPM',record.value('(./Record/MemoryNode/ReservedMemory)[1]', 'int')                                 AS 'ReservedMemory',record.value('(./Record/MemoryNode/CommittedMemory)[1]', 'int')                                AS 'CommittedMemory',record.value('(./Record/MemoryNode/SharedMemory)[1]', 'int')                                   AS 'SharedMemory',record.value('(./Record/MemoryNode/AWEMemory)[1]', 'int')                                      AS 'AWEMemory',record.value('(./Record/MemoryNode/SinglePagesMemory)[1]', 'int')                              AS 'SinglePagesMemory',record.value('(./Record/MemoryNode/CachedMemory)[1]', 'int')                                   AS 'CachedMemory',record.value('(./Record/MemoryRecord/MemoryUtilization)[1]', 'int')                            AS 'MemoryUtilization',record.value('(./Record/MemoryRecord/TotalPhysicalMemory)[1]', 'int')                          AS 'TotalPhysicalMemory',record.value('(./Record/MemoryRecord/AvailablePhysicalMemory)[1]', 'int')                      AS 'AvailablePhysicalMemory',record.value('(./Record/MemoryRecord/TotalPageFile)[1]', 'int')                                AS 'TotalPageFile',record.value('(./Record/MemoryRecord/AvailablePageFile)[1]', 'int')                            AS 'AvailablePageFile',record.value('(./Record/MemoryRecord/TotalVirtualAddressSpace)[1]', 'bigint')                  AS 'TotalVirtualAddressSpace',record.value('(./Record/MemoryRecord/AvailableVirtualAddressSpace)[1]', 'bigint')              AS 'AvailableVirtualAddressSpace',record.value('(./Record/MemoryRecord/AvailableExtendedVirtualAddressSpace)[1]', 'bigint')      AS 'AvailableExtendedVirtualAddressSpace',

TIMESTAMP

FROM (        SELECT TIMESTAMP, CONVERT(XML, record) AS record         FROM sys.dm_os_ring_buffers         WHERE ring_buffer_type = N'RING_BUFFER_RESOURCE_MONITOR'        AND record LIKE '% %'        ) AS x

 

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