Possible duplicate:
What does "GC--" mean in the java garbage collection log?
Consider this gc.log fragment
22760 000: [GC [PSYoungGen: 3900952K-> 68748K (4035904K)] 12250344K-> 8418140K (12424512K), 0,0200860 sec] [Time: user = 0.21 sys = 0.00, real = 0.02 s]
22774.793: [GC-- [PSYoungGen: 3937932K-> 3937932K (4035904K)] 12287324K-> 12326532K (12424512K), 0.9267780 seconds] [Time: user = 2.41 sys = 1.35, real = 0.93 s )
22775.721: [Full GC [PSYoungGen: 3937932K-> 0K (4035904K)] [PSOldGen: 8388600K-> 7444523K (8388608K)] 12326532K-> 7444523K (12424512K) [PSPermGen: 70788K-> 70765] (76765K) Times: user = 5.66 sys = 0.04, real = 5.77 secs]
Everything is clear, but the second entry begins with GC--.
What does it mean? This "collection" seems to have increased memory usage to its maximum capacity. Immediately after this entry, full gc is displayed.
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