GC 问题排查

最近遇到一次GC问题,gc log如下

2014-03-30T11:38:14.997+0800: 3985.625: [Full GC [PSYoungGen: 200672K->0K(1007808K)] [PSOldGen: 2618274K->582573K(2796224K)] 2818946K->582573K(3804032K) [PSPermGen: 34843K->34843K(262144K)], 3.1703780 secs] [Times: user=3.16 sys=0.00, real=3.17 secs]
2014-03-30T11:38:22.582+0800: 3993.210: [GC [PSYoungGen: 807104K->279488K(1086656K)] 1389677K->862061K(3882880K), 1.6827130 secs] [Times: user=30.36 sys=0.00, real=1.69 secs]
2014-03-30T11:38:28.135+0800: 3998.763: [GC [PSYoungGen: 1086592K->265529K(983744K)] 1669165K->1127278K(3779968K), 0.5734360 secs] [Times: user=9.62 sys=0.00, real=0.57 secs]
2014-03-30T11:38:31.715+0800: 4002.343: [GC [PSYoungGen: 937849K->143104K(1035200K)] 1799598K->1269678K(3831424K), 0.5170530 secs] [Times: user=9.27 sys=0.00, real=0.51 secs]
2014-03-30T11:38:34.999+0800: 4005.628: [GC [PSYoungGen: 815424K->142432K(1072448K)] 1941998K->1411686K(3868672K), 0.4969560 secs] [Times: user=8.98 sys=0.00, real=0.50 secs]
2014-03-30T11:38:39.021+0800: 4009.649: [GC [PSYoungGen: 871520K->148256K(1054720K)] 2140774K->1560270K(3850944K), 0.5291480 secs] [Times: user=9.52 sys=0.00, real=0.53 secs]
2014-03-30T11:38:42.718+0800: 4013.347: [GC [PSYoungGen: 877344K->153440K(1104256K)] 2289358K->1713502K(3900480K), 0.6336990 secs] [Times: user=10.03 sys=0.01, real=0.63 secs]
2014-03-30T11:38:46.976+0800: 4017.605: [GC [PSYoungGen: 949280K->226880K(1089664K)] 2509342K->1940350K(3885888K), 0.7684500 secs] [Times: user=13.11 sys=0.00, real=0.76 secs]
2014-03-30T11:38:51.846+0800: 4022.475: [GC [PSYoungGen: 1022720K->177824K(1097984K)] 2736190K->2099742K(3894208K), 1.0153690 secs] [Times: user=17.81 sys=0.17, real=1.02 secs]
2014-03-30T11:38:56.493+0800: 4027.122: [GC [PSYoungGen: 968032K->164992K(1090304K)] 2889950K->2263406K(3886528K), 0.5856320 secs] [Times: user=10.52 sys=0.00, real=0.59 secs]
2014-03-30T11:39:01.328+0800: 4031.957: [GC [PSYoungGen: 955200K->158752K(1122560K)] 3053614K->2421318K(3918784K), 0.5925930 secs] [Times: user=10.63 sys=0.00, real=0.59 secs]
2014-03-30T11:39:09.380+0800: 4040.008: [GC [PSYoungGen: 993376K->173728K(1110144K)] 3255942K->2594894K(3906368K), 0.5859330 secs] [Times: user=10.53 sys=0.00, real=0.58 secs]
2014-03-30T11:39:23.921+0800: 4054.550: [GC [PSYoungGen: 1008352K->182336K(1132224K)] 3429518K->2777326K(3928448K), 0.4648040 secs] [Times: user=8.37 sys=0.00, real=0.46 secs]
2014-03-30T11:39:24.386+0800: 4055.015: [Full GC [PSYoungGen: 182336K->0K(1132224K)] [PSOldGen: 2594990K->1762315K(2796224K)] 2777326K->1762315K(3928448K) [PSPermGen: 34851K->34851K(262144K)], 7.5148640 secs] [Times: user=7.54 sys=0.00, real=7.51 secs]