A process serving application pool 'xxxx' failed to respond to a ping. The process id was '26636'. Event ID 5010

chandan vysyaraju 21

I am facing this error from sometime. Our application hosts multiple application pools in IIS, but this issue happens only with one/single app pool. All the app pool settings are same across the application pools.

Moreover this failed to respond to a ping is happening only when the app pool is idle. This is not observed when the server is continuously handling incoming requests.

The application pool also does not seem to be hung, as it is able to process the incoming requests as and when requested (verified this by disabling ping mechanism).

Also one more observation is that the issue started to happen only after we enabled the Application initialization (warm up) and enabled the pre-load. Idle time-out is disabled and recycling is set to 3AM every day.

IIS version is greater than 7.5.

I am searching, reading some Microsoft documentation to understand "How WAS ping mechanism works internally and what is the type of ping" to see if something is missing with this one app pool. But all I found is that "WAS checks the app pool health periodically (configured) and restarts in case of failure".

Any suggestions in identifying the problem will be very helpful.
Let me know if you need any additional information.

Sam Wu-MSFT 7,036 Reputation points Microsoft Vendor

2021-07-21T02:19:25.28+00:00

@chandan vysyaraju This is a very generic error, there is no specific cause for this. so you need to debug the cause using Debug Diagnostics Tool, this tool will generate detail log file, which will help you to identify the problem.
chandan vysyaraju 21 Reputation points

2021-07-28T04:33:37.337+00:00

I tried using Debug Diagnostics tool, but I feel there is no crash or hang in the app pool at that moment.

Moreover, after setting "skipManagedModules" to true, the issue did not happen.

Still wondering what are the modules that will be skipped during app initialization. Are the ones marked as managed under the Modules section in IIS manager will be skipped ?

Thank you
Chandan
Sam Wu-MSFT 7,036 Reputation points Microsoft Vendor

2021-07-29T08:52:09.14+00:00

@chandan vysyaraju This is a complicated question, you can open a support ticket for this, one of our engineers will help analyse the problem.
chandan vysyaraju 21 Reputation points

2021-08-01T08:25:51.737+00:00

I observed my code little more.. and found that its some where linked to usage of C++ interop (C++/CLI) in the managed .Net/C# code.

Our C++/CLI interface class has a member of type generic.list of user defined structure. This structure is consumed by C# code.

C++/CLI interface internally used unmanaged C++ code.

When I comment the C# code that is using the generic.list declared in C++/CLI, I dont see the issue happening any more.

I am new to C++/CLI and exploring the documentation to get some clues.

Any sort of suggestions will be of great help.

Thank you
Chandan
Hitesh Sachdeva 1 Reputation point

2022-06-22T16:56:16.76+00:00

was that issue solved, i'm facing similar issue in our environment.