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Description:
Paraphrased from the old Service Broker team blog: This wait type is when a thread requires exclusive access to a connection endpoint. This occurs whenever a connection is established to the endpoint and whenever the DMV sys.dm_broker_connections is executed (or the DMV sys.dm_db_mirroring_connections, as database mirroring uses Service Broker as its underlying transport mechanism).
(Books Online description: “Occurs when there is contention to access the state of a Service Broker connection endpoint. Access to the state for changes is serialized.”)
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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 285 in 2008 and 2008 R2, 291 in 2012, and 298 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.
If the number of waits for this wait type is increasing rapidly, it could be that there are a large number of connections being made, or there is repeated inactivity over a connection, as inactive connections will be removed every 90 seconds or so.
Known occurrences in SQL Server (list number matches call stack list):
- TBD
Abbreviated call stacks (list number matches known occurrences list):
- TBD