The following table shows the values that are used when -XX:+UseContainerSupport is set:
Less than 1 GB 50% <size>
1 GB - 2 GB <size> - 512 MB
Greater than 2 GB 75% <size>
The default heap size is capped at 25 GB
The default heap size for containers takes affect only when the following conditions are met:
The application is running in a container environment.
The memory limit for the container is set.
The -XX:+UseContainerSupport option is set, which is the default behavior.
W. Scholz, T. Thüm, S. Apel, and C. Lengauer. Proceedings of the 15th International Software Product Line Conference, Volume 2, page 7:1--7:8. New York, NY, USA, ACM, (2011)