Application Pool worker process is unresponsive

10/12/2018 12:01 PM

9/6/2023 12:07 PM

The following error message appears in the Windows™ Event Viewer:

 

Alert: Application Pool worker process is unresponsive
Source: SolarWinds Orion Application Pool
Last modified by: System
Last modified time: Alert description: A process serving application pool 'SolarWinds Orion Application Pool' suffered a fatal communication error with the Windows Process Activation Service. The process id was '9996'. The data field contains the error number.

Log Name: Application
Source: Application Error
Event ID: 1000
Task Category: (100)
Level: Error
Description:
Faulting application name: w3wp.exe, version: 7.5.7601.17514, time stamp: 0x4ce7a5f8
Faulting module name: mscorlib.ni.dll, version: 4.0.30319.1026, time stamp: 0x53b50a71
Exception code: 0xc0000005
Fault offset: 0x002901c4
Faulting process id: 0x1cf0
Faulting application start time: 0x01d1521c34ae7c7d
Faulting application path: C:\Windows\SysWOW64\inetsrv\w3wp.exe
Faulting module path: C:\Windows\assembly\NativeImages_v4.0.30319_32\mscorlib\f014b1f34734c93956924e68c67ecb55\mscorlib.ni.dll
Report Id: 2319617d-be17-11e5-a078-005056955de8

Network Performance Monitor

The Windows™ Process Activation service causes IIS™ to crash, which generates the event for SolarWinds. 

1. Check the IIS™ logs to see if it was restarted. 
2. Check the system, Windows™, and application logs of the Event Viewer for WPA (Windows™ Process Activation) service causing IIS™ to crash. 
3. If so, investigate the Windows™ issues to prevent IIS™ from crashing. 

If this is caused by the default reset of the worker process, this behaviour is normal underlying behaviour of the OS. The IIS™ recycle time can be set to be predictable and not cause issues with SolarWinds application.

If using AppInsight and monitoring IIS™ using the IIS Template, you can adjust that template to hide the default reset of the worker process.