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.
The log file containing the information referenced will usually be the one named with the hostname on which Tomcat is running. On a simple server (e.g. development environment) this is localhost.<datestamp>.log