Increase Java Heap memory for OEM

 There are certain times when we observer OEM is performing slow or even unable to startup the Admin Server or OMS Server. We can look into few log files below and understand what is exactly causing the issue. Most of the times I have observed Java Heap issue or memory issue.

Sometime it happens due to an old process holding up the session and consuming the memory, the first step is to kill all the processes and remove some of the lok and temp files from the system.

Known error like:

java.lang.OutOfMemoryError: Java heap space.

Troubleshooting steps:

Kill all the old processes:

ps -ef | grep EMGC_ADMINSERVER

ps -ef | grep EMGC_OMS1

ps -ef | grep java

ps -ef | grep opmn

$kill -9 <PID>

The below temp files can be deleted:

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/tmp/EMGC_ADMINSERVER.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/data/ldap/ldapfiles/EmbeddedLDAP.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/tmp/EMGC_OMS1.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/data/ldap/ldapfiles/EmbeddedLDAP.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/data/store/diagnostics/WLS_DIAGNOSTICS000000.DAT

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/data/store/default/_WLS_EMGC_OMS1000000.DAT

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/data/store/diagnostics/WLS_DIAGNOSTICS000000.DAT

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/data/store/default/_WLS_EMGC_ADMINSERVER000000.DAT

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/config/config.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/tmp/EMGC_OMS1.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/tmp/EMGC_ADMINSERVER.lok

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_OMS1/data/nodemanager/*.lck, *.pid, *.state

$EM_INSTANCE_BASE/user_projects/domains/GCDomain/servers/EMGC_ADMINSERVER/data/nodemanager/*.lck, *.pid, *.state

Check current usage:

grep "JAVA Memory arguments" <OMS_INST>/user_projects/domains/GCDomain/servers/EMGC_OMS1/logs/EMGC_OMS1.out

--> This will give the output of the current OMS heap memory.

emctl get property -name OMS_HEAP_MAX

--> This needs Sysman password 

Fix:

Increase it to the desired value, example 4G.

  <OMS_HOME>/bin/emctl set property -name OMS_HEAP_MAX -value 4096M

Restart the OMS

emctl stop oms -all

emctl start oms

Hope this will fix the slowness and heap memory error.

Best wishes,