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SQLTRACE_FILE_BUFFER

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Description:

This wait type is when a thread is waiting for exclusive access to a trace buffer in preparation for writing it to a trace file.

(Books Online description: “Occurs during synchronization on trace buffers during a file trace.”)

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Added in SQL Server version:

2008 R2

Removed in SQL Server version:

N/A

Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 161 in 2008 R2, and 165 in 2012 and 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.

Other information:

I have not seen this wait type be a noticeable contention point.

Known occurrences in SQL Server (list number matches call stack list):

  1. Getting access to a trace buffer before writing it to a trace file

And other similar call stacks.

Abbreviated call stacks (list number matches known occurrences list):

  1. SOS_Task::PostWait+90
    EventInternal<SuspendQueueSLock>::Wait+1f9
    CTraceFileIoProviderAccess::GetExclusiveAccess+13f
    CTraceWriteRequest::InitForFileTrace+6b
    CTraceFileIoProvider::InitializeWriteRequest+29
    CTrace::WriteRecord+74e
    CTraceController::ProduceRecord+706
    CQScanSortNew::TransitionToOutputPhase+187
    CQScanSortNew::PushClose+36
    CQScanSortNew::BuildSortTable+2ec
    CQScanSortNew::OpenHelper+c0
    CQScanNew::OpenHelper+41
    CQScanStreamAggregateNew::Open+30
    CQScanNew::OpenHelper+41
    CQScanXProducerNew::Open+c8
    FnProducerOpen+44
    FnProducerThread+851
    SubprocEntrypoint+a59
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+a8