MOM became unresponsive

Document ID : KB000101380
Last Modified Date : 26/07/2018
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Our MOM within our 10.0 environment was responding very slowly to all end users (both workstation and webview).  I SSH into the MOM server and ran a top and I saw that the MOM Java process was running with +374% cpu (the MOM server has four cores and is a virtual server).  I attempted to run the stop but it did not return.  I then ran a kill -9 on the MOM PID, stopped webview, then started the EM.  After the EM log seemed to have gotten to a point that the MOM was ready, I started WebView.

The question is what happened to cause the MOM to become unresponsive?
APM 10.0 
The MOM became unresponsive due to performing constant GC. The free memory started to keep dropping, and GC keeps going up, and eventually MOM was doing nothing but GC.
Set the G1GC JVM arguments on all EM if running Java 1.7/1.8 with a large heap