# Monitoring / Tuning File Locks in Windows Server 2008

I'm running an instance of Apache Tomcat (5.5) on a Windows 2008 platform. I think I'm seeing an issue related to concurrent file access / locking.

When the number of concurrent HTTP threads is increased beyond the default setting (150), I see (using a site monitoring tool) an increasing number of 'unnatural' delays when serving some static content (.js .gif .png etc). By this, I mean that the server takes 20 seconds plus before starting to send or taking 30 seconds to serve a small (2KiB) file.

When Tomcat is busy (serving over 300 threads), CPU usage averages around 50-60% and disk usage is around 10-30mbps.

On a Linux platform, I could list the files open for a given process and tune the number allowed etc etc. Are there any similar tools for Windows?

Alternatively, is there anything else I should be looking into?

Screenshot of site analysis tool:

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\path\to\handle.exe | find /i "filename"