I'm experiencing an issue where the ASP.NET Cache objects are cleared out every minute or so. The proper behavior is that the cache objects should last 24 hours. This issue started recently when our public web servers were recently upgraded from IIS 5 to IIS 6. The site in question gets about 15,000 page views/hour during peak times. The server admin speculates it could be because of thread recycling in IIS 6.
Any thoughts?
Check the event log - that will tell you if the process is recycling.
Assuming it is, I'm thinking some settings on the recycle limits weren't moved into the Application Pool settings when the machine was upgraded to Win2k3/IIS6. In Win2k/IIS5, the recycle settings are in the processModel node in the machine.config file. These settings need to be migrated to the appropriate application pool(s) in the IIS6 environment (I'm guessing these settings don't auto-migrate).
I'd also review the recycle settings on the application pool. It could be that it is set to recycle too often (by number of minutes or number of requests) or that the memory maximums are set too low.