Control of the JVM's logging operations is accomplished via the command-line. The -Xlog command-line option has an extensive array of parameters and possibilities. Here is one example:

-Xlog:gc+rt*=debug

In this example, we are telling the JVM to take the following actions: 

• Log all messages tagged with, at a minimum, the gc and rt tags
• Use the debug level
• Provide output to stdout