0500284695 18770 2008 480Mbps 800 956120 connector cs csUriQuery csUriStem csUser database debug devices edge edition error failed fast filter fix flashback gigabit graffiti hotfix IIS IIS7 IisManagerAuth isapi KB KB956120 log Login microsoft oracle QFE query quickfix Read recovery server SF_NOTIFY_LOG specification Stem technical timestamp Uri web Win32 write

Tomcat connector isapi_redirect.dll does not handle watchdog_interval properly when not initialized or set to zero (off)

I have discovered an issue with isapi_redirect.dll for tomcat connector on IIS. This issue results in watchdog thread performing near tight loop thus degrading performance on server. If debug tracing is enabled, the thread results in approx 1 GB of trace per minute (depending on your server speed). I have notified the developers with solution and they have applied the patch to the main subversion trunk. If you want to take advantage of the fix you will need to recompile your own dll as it is not being released yet.

Summary: watchdog thread starts regardless of the settings on watchdog interval. If setting is zero, the thread loop incessently. If you do not want or cannot recompile from current sources, you can eliminate the near tight loop by changing behavior of your isapi redirect dll. When watchdog interval is set to zero, the clean up happens on each call, otherwise it happens in background. The issue was that clean up was happening on each call and rapidly on background. By setting watchdog_interval to nonzero value, such as 1, you will no longer clean up on each call, rather the cleanup will happen on background every second. It is a good substitute that will eliminate the near tight loop.

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