IM/IC/IMWS Instances Having High CPU Spikes with Lots of jGroup NACK Log Messages

(Doc ID 2102316.1)

Last updated on APRIL 11, 2016

Applies to:

Oracle Knowledge - Version to [Release 8.5]
Information in this document applies to any platform.


Multiple IM/IC/IMWS instances in the same env shows high CPU spikes and many jGroup NACK messages logged in their corresponding logfiles.  From the network point of view, you will also notice spike of UDP multicasting traffic to&from those IM/IC/IMWS instances with high CPU.  Those IM/IC/IMWS instances with high CPU may move/switch randomly to another set of IM instances in the same env over time. 

For example, IM1/IC2/IMWS1 instances are having high CPU spikes in the morning hours and then couple hours later, the issue may move/switch to randomly another combination set of instances (say IM1/IC2+IC3/IMWS2) and then another couple hours later, the issue may again move/switch to randomly another different combination set of instances (say IM1+IM2/IC3/IMWS1)... etc.


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