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WAIT_XTP_HOST_WAIT

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Description:

This wait type is when a thread is waiting for an In-Memory OLTP operation that was started by the regular Engine.

(Books Online description: “Occurs when waits are triggered by the database engine and implemented by the host.”)

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Added in SQL Server version:

2014

Removed in SQL Server version:

N/A

Extended Events wait_type value:

Maps to the XTP_HOST_WAIT map_value in sys.dm_xe_map_values.

The map_key value in sys.dm_xe_map_values is 896 in 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:

This wait type is one that I usually filter out as a benign wait when doing wait statistics analysis.

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

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

  1. Waiting for an In-Memory OLTP wait to end (in this case, when shutting down an In-Memory OLTP process after a failure)

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

  1. SOS_Task::PostWait+9e
    EventInternal<SuspendQueueSLock>::Wait+1fb
    HkHostWait::Wait+ce
    hkengine.dll!HkSetOfflineShutdownFlag+3f30b
    HkHostReportFailure::KillProcess+372
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+a8