What does UseContainerSupport VM parameter do?

Issue

What does this option do in docker file?

ENTRYPOINT java -XX:+UseContainerSupport $JAVA_OPTIONS -jar /myapp.jar

Will the docker container start without this parameter? I checked one article which says

enable memory support

but it is still not clear to me.

Solution

Yes. The container will start without -XX:+UseContainerSupport.

-XX:+UseContainerSupport is used to allocate a larger fraction of memory.

To prevent the JVM adjusting the maximum heap size when running in a container, set -XX:-UseContainerSupport.

In addition to that, https://www.eclipse.org/openj9/docs/xxusecontainersupport/ might be helpful.

Answered By - ionenorch