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rob_rpm

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IIS 6.0 Application Pool recycles itself every few minutes

Hi,

I'm running IIS 6.0 on Windows Server 2003 64 bit (dual processors, 2Gb RAM).  Have just recompiled a .NET 1.1 site to .NET 2 and now the Application Pool for the site seems to randomly recycle itself.

The site is fairly busy, averaging 5 - 10 requests/sec for 20 hours a day.  It makes extensive use of session variables to reduce DB server load and obviously when the pool gets recycled all session variables get lost.

What is very strange is that just before recycling, there is a HUGE spike in the Request/Sec and Sessions Active as reported by Performance Monitor - as in requests goes up to around 4295420459.

The server has the latest service patches and I have scanned for trojans and visruses and the server is clean.

Any ideas what I should look for?

Thanks a lot

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sleep_furiously

Is anything useful logged in the system Event logs when the process is recycled?
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ASKER

No, unfortunately there is nothing in the Event Logs.

In the Application log, the only entries come from ASP.NET errors when they lose their session variables.

In the System log the only W3SVC entries are "A worker process with process id of '4996' serving application pool 'Powering' has requested a recycle because the worker process reached its allowed processing time limit."
(I have a 2 hour Recycle time on the worker process)

So it appears IIS is recycling the process, but not recording it...

In the Task Manager I can see the memory usage for w3wp.exe drop from 300mb or whatever down to 20mb each time this happens.

As I said above, the REALLY strange thing is that the counters for requests/sec, sessions active, request succeeded go through the roof just before it happens - always to about 4.29 billion!!!
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sleep_furiously

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