Tools to analyze GC logs

The Java GC logs are one of the places where we can start debugging an application in the event of a performance issue. The GC logs provide important information, such as:

• The last time the GC ran
• The number of GC cycles run
• The interval at which the GC ran
• The amount of memory freed up after the GC ran
• The time the GC took to run
• The amount of time for which the JVM paused when the garbage collector ran
• The amount of memory allocated to each generation

The following is the sample GC logs:

2018-05-09T14:02:17.676+0530: 0.315: Total time for which application threads were stopped: 0.0001783 seconds, Stopping threads took: 0.0000239 seconds
2018-05-09T14:02:17.964+0530: 0.603: Application time: 0.2881052 seconds
.....
2018-05-09T14:02:18.940+0530: 1.579: Total time for which application threads were stopped: 0.0003113 seconds, Stopping threads took: 0.0000517...