IIS Application Pool Idle Time-out does not work
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we are having a few 2008 servers running IIS 7. On one set of server the web applications are running ok, but on the second we get a "ORA-03114: not connected to ORACLE" error from time to time - usually after the web application is idle for a while, on first access. After a few refreshes it works OK.

In the logs I observed that on the first set of servers, after a 20 minute idle time the application is being closed (as expected, as default Idle Time-out is set to 20 minutes). But on the second set of servers, even they have the same settings (apparently)), the application is not being closed. 

Even more than that, after recycling the application pool on the second set of servers, the site is working ok. Let it idle for 20 minutes, access it and you get the error. I've changed the Idle Time-out to 5 minutes, and the error is generated after 5 minutes of idle.

Currently my best guess is that, even there is no recycling done on the second set of servers, something happens to the connections that are in the Connection Pool, and next time you try to open the site, these invalid connections are being picked up at first and you get a not connected to ORACLE error. A few site refreshes iterate through the invalid connections, and then a new valid connections is created and added to the pool.

It's a very strange issue, couldn't find any similar ones on the net, so if anyone has any idea of what could that be I'd be very grateful. 