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I have a problem with IIS that I cannot resolve.

Given that:

  • the Windows Event Viewer doesn't detect any application level errors
  • with debugdiag two rules are active for monitoring exceptions (of the stackoverflow type) and on excessive use of resources and have not performed any dumps

Quite randomly (infrequently) the application responds to the front-end with the error message "HTTP Error 503. The service is unavailable.".

Trying to reboot from the prompt via the iisreset command fails and remains stopped and trying to reboot directly from IIS I get the following error message "Web Publishing Service (W3SVC) stopped. Websites cannot be started if the Web Publishing Service (W3SVC) is not running";

See the following link:

enter image description here

To restart the application pool the only solution is to kill the process and then restart it.

What could it depend on? Could it be some other service that can give IIS problems?

I hope someone can give me some useful information.

Thanks in advance.

Gargano
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1 Answers1

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I think you have two questions:

  1. How you can detect the root cause of 503 error

503 error => common cause is the application crash. You should set debugdiag rules to collect dump for application crash and analysis the dump for the crash reason.

  1. What the dependencies are for W3SVC and how we can solve this "not running" issue

Dependencies are:

  • Windows Process Activation Service
  • Remote Procedure Call (RPC)
  • DCOM Server Process Launcher
  • RPC Endpoint Mapper

You can refer to this answer about how to solve "w3svc service is not running error".

IIS w3svc error

Hope helps.

Xin Fang
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  • Hi, I have already activated the debug rules diag but when the application crashes no dump is done. This crash occurs between night and early morning (the application is hardly used at this time). The link you passed me is not reachable, could you turn it over again? – Gargano Jun 11 '21 at 06:50
  • Hi, I have updated the link and please kindly check that. Regarding the dump file, you can refer to this link: https://stackoverflow.com/a/32720307/12871232. Excerpts from the link: At times CLR calls TerminateProcess function when it encounters fatal exceptions (stack overflow being one of them). So if your process is crashing with these kind of exceptions then you won't get dumps using the default rule and you should change the rule to include the ntdll terminateprocess breakpoint which is present in the default breakpoint list. – Xin Fang Jun 11 '21 at 09:29
  • Hi, could you explain me and point me the steps to configure the rule on debug diag to include the ntdll terminateprocess? Thank you – Gargano Jun 11 '21 at 09:53
  • You can create a rule with steps: Add Rule -> Crash -> A specific process (choose your w3wp process) ->Breakpoints (in Advanced Settings) -> Add Breakpoint -> Choose 'Ntdll!ZwTerminateProcess'. Then activate this rule. – Xin Fang Jun 15 '21 at 03:30