Turning on GC logging at runtime#
https://plumbr.io/blog/garbage-collection/turning-on-gc-logging-at-runtime
The -XX:+PrintFlagsFinal lists all the JVM options, out of which the “manageable” options are currently of interest. These are dynamically writeable through the JDK management interface (com.sun.management.HotSpotDiagnosticMXBean API). The very same MBean is also published through JConsole. To my liking, the command-line version is a lot more convenient though.
my-precious me$ jinfo -flag +PrintGCDetails 12278
my-precious me$ jinfo -flag +PrintGC 12278