Web Connection
Too many COM instances launch
Gravatar is a globally recognized avatar based on your email address. Too many COM instances launch
  Michael Hogan (Ideate Hosting)
  Jul 23, 2019 @ 11:17am

I really need to pin this down...

My app is running DLL Version: 5.72 (.NET Module) and is set up for 4 COM instances running LoadBased

It runs like a COM champ for the most part - but once in awhile some extra instances get fired up and the site stops responding.

When this happens, only 4 COM instances show up on the 'Web Connection Module Status Page' but if I look at Process Explorer to look at the windows processes, I see additional instances with the same parent process (winnt.exe/services/svchost.exe/myapp.exe).

I can compare the process ID's on the maintenance page with the PID's in process explorer to figure out which ones to kill (they seem to appear above the 'good' instances) and if I kill off the PIDs that don't appear on the maintenance page then the remaining 4 begin to respond again.

There are several websites on this server but only one uses webconnect. I have three different mappings but one of them uses a different "Handler" - is it possible the additional instances pop up for that reason (*.quote)?:

*.int: Westwind.WebConnection.WebConnectionHandler,WebConnectionModule

*.wc: Westwind.WebConnection.WebConnectionHandler,WebConnectionModule

*.quote: Westwind.WebConnection.WebConnectionHandler

Otherwise, is there something I can log to file at startup to pin down the cause?

Gravatar is a globally recognized avatar based on your email address. re: Too many COM instances launch
  Rick Strahl
  Michael Hogan (Ideate Hosting)
  Jul 24, 2019 @ 04:11am

Definitely make sure all the handler mappings are identical. It's possible that some other instance of the DLL is getting loaded which could account for the extra instances.

Instances with the same parent process ID is odd - usually when this happens it's due to the host process (the IIS Application Pool) dying without a chance to kill the extra instances). This is rare but can happen if the COM server crashes repeatedly which causes a small resource leak each time it happens. Repeated failures eventually can cause the host process to crash.

Other than that I don't know. There have been many improvements to the COM manager since 5.72 so it's possible that some of this may have been fixed in subsequent releases, but I couldn't point you at anything specific.

+++ Rick ---

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