Getting alarms about Garbage Collection:
"The garbage collection overhead on <serverName> is at xx%. This exceeds the garbgage collection overhead fatal threshold of yy%."
How to troubleshoot and fix it?
Check JVM memory allocation via "Management Server | Diagnostic | Performance | FMS Overview | JVM Memory Usage"
The memory can be changed in $FMS_HOME/config/server.config file. The default JVM memory allocation settings are:
64-bit: -Xms{same as Xmx}m -Xmx{75% of total memory < 4096}m
which says, for a 64-bit machine allocate 4 GB of memory and if it cannot get that (because the box does not have it available), grab 75% of what is available.
Since the Foglight JVM is now only allowed 4 GB of total memory and the OS was using up some of that, Foglight only allocated 1.5 gb to JVM.
This is what is causing the GC Alarms and a noticable performance impact of FMS.
Increase the assigned memory to Foglight to 4 - 8 GB as described in this solution.
