How to prevent duplicated .APM NET Agents in the Metric View?
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How to prevent duplicated .APM NET Agents in the Metric View?


Article ID: 218700


Updated On:


CA Application Performance Management (APM / Wily / Introscope)


The investigator is reporting 2 instances for the same .NET application, they both has the same PID number

Why it is listing 2 instances and how to prevent this duplication?


APM Agents .NET 10.7.0


This could be the known side-effect with IIS app pool default configuration of overlapped recycle that the existing worker process would be terminated later after the new worker process would start up first.
Because of this recycle behavior, the new agent instance would be named with the %1 suffix to avoid duplicate agent naming since the older worker process for the same app would be still up and so would be the corresponding agent instance.  The older worker process would eventually terminate and its agent instance would disconnect.  The newer agent instance could then be able to be renamed without the %1 suffix.  


This is by design since there are actually two worker processes for the same application being monitored at the same time. 

You can consider disabling the overlapped recycle setting in IIS app pool configuration, but this is not recommended as it can impact the IIS app availability during the recycle period.