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Description:
This wait type is just as the Books Online entry describes. You will see this wait type at most once per 823/824 error.
(Books Online description: “Occurs when the background suspect page logger is trying to avoid running more than every five seconds. Excessive suspect pages cause the logger to run frequently.”)
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Added in SQL Server version:
Pre-2005/2005
Removed in SQL Server version:
N/A
Extended Events wait_type value:
The map_key value in sys.dm_xe_map_values is 231 in 2008 and 2008 R2, 238 in 2012, and 245 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, but if you’re seeing this wait type become prevalent, you are experiencing repeated 823/824 errors. This either indicates a large amount of corruption, or the workload is repeatedly hitting the same set of corrupt pages.
Known occurrences in SQL Server (list number matches call stack list):
- Waiting before checking the bad page list after processing the previous bad page
Abbreviated call stacks (list number matches known occurrences list):
- SOS_Task::PostWait+9e
SOS_Task::Sleep+149
BadPageList::ProcessTskPkt+198
OnDemandTaskContext::ProcessTskPkt+3e2
SystemTaskEntryPoint+426
OnDemandTaskContext::FuncEntryPoint+25
SOS_Task::Param::Execute+21e
SOS_Scheduler::RunTask+ab