This tip pertains to all versions of SharePoint and no versions of SharePoint. It is really more of an IIS troubleshooting tip.
When strange things happen to IIS application pools I am reminded of the old public service announcement, “Do you know where your children are?” Well, do you know what your application pools are doing? When was the last time one restarted? What is the history of restarts? If you cannot answer these questions read ahead.
To find out when an application pool has started or how long it has been running use Process Explorer to view the time the application pool process started.
- Download Process Explorer from http://live.sysinternals.com/procexp.exe.
- Run Process Explorer as a local administrator.
- Scroll down the main Process Explorer window until you see some processes whose names are w3wp.exe.
- Enable the Command Line column in the main Process Explorer window by right-clicking on a column header and selecting ‘Select Columns’.
- Add the ‘Command Line’ column and click OK.
- Find the application pool that you want more information on by expanding the ‘Command Line’ column and finding the name of the application pool.
- Double-click the process in the main window; this will bring up the Properties page. Look at the Started time.
Now that you can find out the current start times of application pools how do you get a history of when application pools have been restarted.
Enable logging of application pool restarts to the Event Log; http://support.microsoft.com/kb/332088. To make a long KB simple; use the following command to enable the logging of all types of restarts for an application pool:
cscript adsutil.vbs Set "w3svc/AppPools/<App Pool Name>/LogEventOnRecycle" 255
To disable logging of recycle events for an application pool use the following:
cscript adsutil.vbs Set "w3svc/AppPools/<App Pool Name>/LogEventOnRecycle" 0
After the logging is set there is no need to IISRESET or reboot, the change is instant.
To view the recycle events open Event Viewer on the machine and look in the System Event Log for the following event ids: 1074, 1075, 1076, 1077, 1078, 1079, 1080 and 1177.
Now you can keep track of those application pools.