Ok, so there are various symptoms here (clients and and our own employees complaining of intermittent slowdowns, getting 'kicked out' to login page or just having a save request not properly save the submitted data).

The environment:

  • Windows Server 2008 (Datacenter), Service Pack 2, 64-bit, 2x2.8 GHz processors, 7.5 GB RAM
  • MS SQL Server 2008 (running on the same machine)
  • IIS 7

There are ~10 websites running on the server, each in their own application pool - most of these pools are running in Integrated mode, 2 are in Classic, all are on .NET 2.0 and all run as ApplicationPoolIdentity.

I'm trying to analyze, diagnose, and troubleshoot and am struggling with where to get more info about what could be happening.

Here are some steps i have already taken:

  • Set each application pool to recycle once per day, and removed any other automatic recycling
  • Set a Virtual Memory Limit for each to 1024000KB (1GB)
  • Enabled ALL 'Generate Recycle Event Log Entry' entries (Config Changes, Isapi Reported Unhealthy, Manual Recycle, Private Memory Limit Exceeded, Regular Time Interval, Request Limit Exceeded, Specific Time, Virtual Memory Limit Exceeded)

I have seen the app pool processes recycle (in Task Manager) - a new one will start up, and then the first one dies off - and this has happened without the memory or time going over the settings.

This is a fairly new server, and most of these came from Windows Server 2003/IIS6.

Any 'next steps' for setting up information gathering, logging, diagnosing, etc. would be much appreciated!



The app pool advanced settings allows you to turn on extra logging for the app pool. You can turn on all of the app pool recycle logging. It shouldn't be chatty in a healthy situation and you don't mind if it's chatty while you're troubleshooting.

Then in Event Viewer you should get an event logged every time your app pool recycles.

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Just a note on the memory recycle - you might not notice it hit the Virtual Bytes limit if you're looking at it in Task Manager, but it should still trigger an event if the event loging settings are set.

Incidentally, any change to App Pool settings will trigger a recycle. So don't go reconfirming settings unless you want that to happen!

To avoid that, change the property DisallowRotationOnConfigChange, and that will cause App Pools not to recycle until they're scheduled or forced to, when App Pool settings are modified.

WAS should log events in the System log when it takes corrective action; App Pool failures will generally log to System or Application (Windows Error Reporting or App issues).

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