Seeing a Stats Aggregation Out of Memory (OOM) error and the EM shuts down.

Document ID : KB000006205
Last Modified Date : 14/02/2018
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  Seeing the Introscope Enterprise Manager shutting down with the following error:

[ERROR] [Thread-66] [] [CheckDatabase.Thread1] [$CheckDatabasePeriodically] Unexpected error checking database
java.lang.OutOfMemoryError: Java heap space



APM 10.x APM Database: Oracle (All supported releases)

  Insufficient heap is assigned to APM CE (CEM) Stats Aggregation Service. 



 Heap Tuning for Stats Aggregation Service

 To tune the JVM heap settings for the daily statistics aggregation process, edit the dailystats.jvmArgs property in the <EM_Home>/config/ file (To not have this value overridden during an upgrade, use instead.)

 To overcome this issue we need to increase heap for daily aggregation. Before doing so, make sure that this machine enough physical RAM.

As an example: EM (6GB) + Aggregation (4GB) + extra (2GB) = 12GB.

  Backup the or file on the Introscope Enterprise Manager where CEM Stats Aggregation Service runs.

  To increase Java heap for daily aggregation, open the or file  and increase the heap size as shown below.


As an example: From Default 256MB to 4GB of minimum and maximum settings.

dailystats.jvmArgs= -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:+UseBiasedLocking -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -Xms256M -XX:ThreadStackSize=128

with this

dailystats.jvmArgs= -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:+UseBiasedLocking -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -Xms4096m -Xmx4096m -XX:ThreadStackSize=128 
   Then restart the Introscope Enterprise Manager running the APM CE (CEM) Stats Aggregation Service.