How to Increase the JVMs for an OC4J Instance in R12

If You want to increase the number of JVMs to handle the user load (Typically 1 JVM per CPU) in Oracle Applications R12 which is configured in OC4J technology follow the process listed below. Just keep in mind that if you want to increase the number of JVMs there should be sufficient resources available on the Operating system.

Use top, vmstat or sar to find out the resource availability on the O/S.

The procedure to increase the JVMs in Oracle Applications R12 is as below

1. Login as the applmgr user

2. cd to the $ORA_CONFIG_HOME/10.1.3/opmn/conf

3. Edit the file opmn.xml

For Example , if you want to increase the JVMs for oacore process under the OC4J ,
You will see a line which looks as below


<process-set id="default_group" numprocs="1"/>



The Last line high lighted in bold numproc=1 is the parameter. In this Example oacore is running with 1 JVM. If you want to increase the JVMs to 2 then increase the numproc parameter to 2 with the following line



4. Once the changes has been done.. reload the opmn using the following command

cd $ADMIN_SCRIPTS_HOME
./adopmnctl.sh stopall ( Caution: This action will disrupt the application users. Please intimate the users about the disruption)
./adopmnctl.sh startall
5. TO validate whether there are 2 jvms started for oacore or not, use the opmnctl status command to see whether there are 2 jvms started

For Example, the following opmnctl status command
-------------------+--------------------+---------+---------
ias-component | process-type | pid | status
-------------------+--------------------+---------+---------
OC4J | oacore | 4848 | Alive
OC4J | oacore | 4132 | Alive

You will see there are 2 processes started for oacore.