You can configure on-heap limits using Java command-line options.

The available options are:

• -Xmx: to set the maximum on-heap size of the JVM.
• -Xms: to set the initial on-heap size of the JVM.
• -XX:NewSize: to set the initial size of the young generation
• -XX:MaxNewSize: to set the maximum size of the young generation

The following shows an example to configure the on-heap limits using -XX:MaxNewSize option in a Java application:

java -Xmx<size_mb>m -Xms<size_mb>m -XX:MaxNewSize=<size_mb>m -XX:NewSize=<size_mb>m 

If you are using a JShell client, then you can set the JAVA_OPTS environment variable before starting the shell. For example:

export JAVA_OPTS="-Xmx<size_gb>g -Xms<size_gb>g -XX:MaxNewSize=<size_gb>g -XX:NewSize=<size_gb>g "
cd /opt/oracle/graph/
./bin/opg-jshell