[mapguide-users] Unhandled exceptions in IIS web tier

[Berg, James]

I struggle with events related to mapguide because I don't really understand them. Several times a day we get logs like 

"A process serving application pool 'MapGuide25AppPool' suffered a fatal communication error with the World Wide Web Publishing Service. The process id was '17544'. The data field contains the error number. "

with the source being W3SVC. W3svc.exe is the process related to the application pool in IIS that represents the website that holds mapguide.

It's tricky for me to figure out what the cause of the errors are. It could be a memory leak in my own application (fairly likely,) so I can't blame mapguide for it off the bat.

Basically, whenever my application pool fails, maps stop loading until I manually recycle the application pool. Without knowing the exact cause, the only workaround I've come up with is to configure my application pool to automatically recycle whenever it accumulates a certain amount of virtual memory. I've got it set to recycle at 800 megabytes, but I might decrease that number if problems persist. 

The hope is that frequent recycling will prevent errors.

It's also important to note that my application does not use InProc session handling in web.config. That's the default setting and application pool recycling would reset any sessions (very bad.)  Instead I use the StateServer setting. That way session aren't reset upon application pool resets.