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asp.netiisapplication-pool

What causes an application pool in IIS to recycle?

I have been searching for info on this to no avail. The context of why i need this is another question I asked here. More specifically, does creating/updating/deleting files in App_Data cause a pool recycle?

If someone could provide a detailed list of what causes a recycle, that would be great.

UPDATE: As two users already noticed I would also be happy to an answer specifying reasons for recycling the AppDomain only and not the whole pool.

Solution

  • Two different effects:

    • The AppPool process is the host for potentially multiple AppDomains. Typically this can be recycled by a number of effects. These could be time (every n hours), lack of requests, memory use, etc.; all configured in IIS Config Manager.

    • The AppDomain, the hosted instance of your application root, can be cycled more frequently without affecting other AppDomains in the AppPool. Tess's post on AppDomain recycling is pretty insightful.

    You are writing to a folder monitored for recompilation. This will trigger the AppDomain recreation at some point.

    The event log will help you determine what cause initiated the recycle.