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Description:
This wait type is a generic wait for when a thread is calling one of several Windows functions related to Winsock (Windows sockets).
(Books Online description: N/A)
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Added in SQL Server version:
2008
Removed in SQL Server version:
N/A
Extended Events wait_type value:
The map_key value in sys.dm_xe_map_values is 490 in 2008 and 2008 R2, 538 in 2012, and 554 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:
I have not seen this wait type be a noticeable contention point.
Note that when a thread calls out to Windows, the thread changes from non-preemptive (SQL Server controls the thread) to preemptive (Windows controls the thread) mode. The thread’s state will be listed as RUNNING, as SQL Server doesn’t know what Windows is doing with the thread.
Known occurrences in SQL Server (list number matches call stack list):
- Setting the hostname for a connection during database mirroring
- Setting the hostname for a connection during database mirroring
And other similar call stacks.
Abbreviated call stacks (list number matches known occurrences list):
- SOS_Task::PopWait+b1
AutoSwitchPreemptive::~AutoSwitchPreemptive+95
DbmGlobalStateMgr::SetHostName+209
DbmServer::GetServerConnectString+6e
LSConfigureRequest::Init+5c
LSConfigureRequestV2::Init+52
LsConnectionStateMachine::SendConfigureRequest+cb
LsConnectionStateMachine::StartingAction+d0
LsStateMachineBase::PostEvent+1d7
LsStateMgr::ProcessEvents+113
DbmDatabaseStateMgr::MasterThreadRoutine+303
SOS_Task::Param::Execute+21e
SOS_Scheduler::RunTask+ab - SOS_Task::PopWait+b1
AutoSwitchPreemptive::~AutoSwitchPreemptive+95
DbmGlobalStateMgr::SetHostName+209
DbmGlobalStateMgr::Init+94
DbmServer::Init+1b0
DBMirroring::UpdateEndpoint+1f
IBrokerEndpointConfig::PostTransactionCommitNotify_Change+ff
VLR_RegisterEndpoint::CommitAndRelease+7b
XdesRMReadWrite::CommitAllVirtualLogRecs+e4
XdesRMReadWrite::PreDestruct+23e
XdesRMFull::~XdesRMFull+b2
XdesRMFull::`vector deleting destructor’+14
XactRM::SinglePhaseCommit+1e3
XactRM::CommitInternal+472
FullXactImp::Commit+33f
CMsqlXactInternalReadWrite::Commit+19
CMsqlXactImp::Commit+1d6
CXStmtDDL::FinishNormalImp+e1
CMsqlExecContext::ExecuteStmts<0,1>+9d8
CMsqlExecContext::FExecute+a58
CSQLSource::Execute+86c
process_request+a57