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Why would one of our application pools in IIS v6.0 report itself as unhealthy.

The event viewer reports: ISAPI 'C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll' reported itself as unhealthy for the following reason: 'Deadlock detected'.

After this point it enter rapid failure mode and switches off the application pool.


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Unfortunately there isn't a simple answer as to why this would happen. Essentially, it means that the process has run out of threads to continue processing requests.

You need to have IIS generate a dump file that you can then analyze and determine the cause of this.

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Thanks for the input there. We're going to schedule time for early January to do this. For the moment I'm going to be switching off the rapid fail protection. Whenever this occurs it's almost always preceded by a connection failure to the Oracle database. Could this be the case, or would you say this is happening purely because it's run out of threads? – Jacques Dec 15 '10 at 8:13

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