The error “The requested resource is in use” is fairly common in Windows. Since ASP is programmed on a Windows platform, it means that many ASP programmers run into this complaint.
Don’t necessarily blame ASP itself for this error. If you’re getting this alert with ASP programming calls, it usually means something in the overall Windows environment is not up to date.
It often means that something in Windows isn’t maintaining its coherence properly, the locking and unlocking of access to resources. You generally don’t do that in ASP.
Be sure to run through all the updates available for Windows, IIS, and ASP. Reboot.
Once you’ve taken care of the main reasons, a few times the error The requested resource is in use is caused in ASP by the ISAPI caching setting in IIS.
If you go into IIS for our site and go into the Home Directory area, click on the Configuration button. You will see a “Cache ISAPI Applications” option. You should ONLY turn this off for testing purposes. When you turn it off, if two people try to hit the same page at the same time they will get:
The requested resource is in use
When this is off, you will also see an event log entry for EVERY time an ISAPI is loaded and unloaded from memory – i.e. constantly.
Check this box in order to cause the items to cache in memory – therefore always being available.