Reading garbage collection activity logs

When we executed the MemoryIssues application with -verbose:gc

[GC 163972K->163916K(237748K), 0.1814933 secs]

[Full GC 229516K->214339K(237748K), 0.8321936 secs]

Let's explore the different sections in these log statements by defining the general log structure, as follows:

Occupied space before -> occupied space after (total committed space size), time taken in space activity The first line is for a minor garbage collection activity (that is, young generation only)and the second line is for a full garbage collection activity (that is, including the old generation as well). The following diagram describes how to read these details:

We can get more information printed on the console by using the additional JVM parameter -XX:+PrintGCDetails.