18 October 2006
IIS 6: Logging Application Pool Recycling Events to the Event Log
By default, IIS 6 logs application pool recycling events to the event
log when memory limits are exceeded (noting that a memory limit is not
set by default) and after elapsed time (29 hours by default).
There
are other reasons for application pool recycling events, such as
modifications to configuration files and manual recycling requests
issued by administrators. Logging of recycling events to the event
log is controlled by the LogEventOnRecycle metabase property
(interpreted as a bitflag).
Updating the LogEventOnRecycle
property to consider other recycling events can be achieved using
adsutils.vbs, or by manually editing the metabase. The following
examples enable logging for all possible recycling events.
Updating using adsutils.vbscscript adsutil.vbs Set w3svc/AppPools/DefaultAppPool/LogEventOnRecycle 255
Updating by Editing the Metabase- Stop IIS: iisreset -stop
- Backup the metabase (found at: %WINDIR%\system32\inetsrv\MetaBase.xml)
- Modify the LogEventOnRecycle property:
Branch : /LM/W3SVC/AppPools/
Key Name: LogEventOnRecycle
New Value: 255 (default is 137)
The metabase can be edited using the Metabase Explorer (available as part of the IIS 6 Resource Kit Tools).
- Start IIS: iisreset -start
For further information about the LogEventOnRecycle metabase property, see the following articles:
How to modify Application Pool Recycling events in IIS 6.0
LogEventOnRecycle Metabase Property
Also
note that IIS creates worker processes for application pools on demand.
Thus, a recycle request may be issued but not result in an event log
entry if no actual worker process is active. For more information:
Why IIS6 Application Pool Recycle Events are Not Logged