SUN JDK 1.4.2, 1.5 GC Option

Sun GC option (build 1.4.2_18-b06 에서 Test, JDK 1.5 동일)

   -Xms64m                      : 최소 heap size
   -Xmx256m                    : 최대 heap size
   -XX:PermSize=64m        : 최소 perm size
   -XX:MaxPermSize=64m  : 최대 perm size
  
   -verbose:gc                              : gc log 출력
   -Xloggc:./gclog.log                  : gc log file 기록
   -XX:+PrintGCDetails                 : 상세출력
   -XX:+PrintGCTimeStamps        : timestamp 출력
   -XX:+PrintHeapAtGC                 : gc한 상태의 heap 영역 출력   
   -XX:+PrintTenuringDistribution : Print tenuring age information
   -XX:+ShowMessageBoxOnError  : JVM crach 발생시 메세지 박스 출력(Sun에선 공식설명 없으나 동작함.)

  EX) -XX:+ShowMessageBoxOnError  
  ==============================================================================
  Unexpected Error
  ------------------------------------------------------------------------------
  SIGSEGV (0xb) at pc=0xb7fc0402, pid=17842, tid=3085269200
  
  Do you want to debug the problem?
  
  To debug, run 'gdb /proc/17842/exe 17842'; then switch to thread -1209698096
  Enter 'yes' to launch gdb automatically (PATH must include gdb)
  Otherwise, press RETURN to abort...
  ==============================================================================

GC Log Example

EX) -verbose:gc -Xloggc:./gclog.log

 16.479: [GC 3976K->1363K(65088K), 0.0347330 secs]
 17.525: [GC 5203K->3923K(65088K), 0.0574820 secs]
 21.643: [GC 57684K->55123K(65088K), 0.0018090 secs]
 21.645: [Full GC 55123K->20563K(65088K), 0.0441540 secs]
 21.748: [GC 41043K->41043K(65152K), 0.0019690 secs]
 21.751: [Full GC 41043K->41043K(65152K), 0.0147680 secs]

EX) -verbose:gc -Xloggc:./gclog.log -XX:+PrintGCDetails

 16.412: [GC 16.413: [DefNew: 3976K->83K(4544K), 0.0305770 secs] 3976K->1363K(65088K), 0.0310270 secs]
 17.453: [GC 17.454: [DefNew: 3923K->83K(4544K), 0.0495660 secs] 5203K->3923K(65088K), 0.0497540 secs]
 21.399: [GC 21.399: [DefNew: 2644K->83K(4544K), 0.0023250 secs]21.402: [Tenured: 55040K->20563K(60544K), 0.0451070 secs] 57684K->20563K(65088K), 0.0482600 secs]
 21.508: [GC 21.508: [DefNew: 0K->0K(4608K), 0.0018920 secs]21.510: [Tenured: 41043K->41043K(60544K), 0.0150950 secs] 41043K->41043K(65152K), 0.0178590 secs]
 22.827: [GC 22.827: [DefNew: 0K->0K(5184K), 0.0021710 secs]22.830: [Tenured: 82003K->41043K(109372K), 0.0770740 secs] 82003K->41043K(114556K), 0.0800650 secs]
 23.029: [GC 23.030: [DefNew: 0K->0K(8256K), 0.0027250 secs]23.033: [Tenured: 82003K->82003K(109372K), 0.0708040 secs] 82003K->82003K(117628K), 0.0756220 secs]
 24.841: [GC 24.842: [DefNew: 0K->0K(10368K), 0.0035190 secs]24.845: [Tenured: 163923K->82003K(218596K), 0.1448700 secs] 163923K->82003K(228964K), 0.1502950 secs]
 25.239: [GC 25.240: [DefNew: 0K->0K(16448K), 0.0030840 secs]25.243: [Tenured: 163923K->163923K(218596K), 0.0186830 secs] 163923K->163923K(235044K), 0.0246090 secs]
 25.264: [Full GC 25.264: [Tenured: 163923K->163922K(241984K), 0.2243630 secs] 163923K->163922K(260160K), [Perm : 983K->983K(65536K)], 0.2252740 secs]

EX) -verbose:gc -Xloggc:./gclog.log -XX:+PrintGCDetails -XX:+PrintGCTimeStamps

 16.426: [GC 16.434: [DefNew: 3976K->83K(4544K), 0.1745330 secs] 3976K->1363K(65088K), 0.1757260 secs]
 17.625: [GC 17.626: [DefNew: 3923K->83K(4544K), 0.1504880 secs] 5203K->3923K(65088K), 0.1515850 secs]
 21.638: [GC 21.639: [DefNew: 2644K->83K(4544K), 0.0023950 secs]21.641: [Tenured: 55040K->20563K(60544K), 0.0454170 secs] 57684K->20563K(65088K), 0.0485820 secs]
 21.745: [GC 21.746: [DefNew: 0K->0K(4608K), 0.0017730 secs]21.748: [Tenured: 41043K->41043K(60544K), 0.0139250 secs] 41043K->41043K(65152K), 0.0167400 secs]
 23.052: [GC 23.052: [DefNew: 0K->0K(5184K), 0.0021500 secs]23.054: [Tenured: 82003K->41043K(109372K), 0.0748140 secs] 82003K->41043K(114556K), 0.0792520 secs]
 23.249: [GC 23.250: [DefNew: 0K->0K(8256K), 0.0019270 secs]23.253: [Tenured: 82003K->82003K(109372K), 0.0691750 secs] 82003K->82003K(117628K), 0.0740190 secs]
 25.046: [GC 25.047: [DefNew: 0K->0K(10368K), 0.0041480 secs]25.051: [Tenured: 163923K->82003K(218596K), 0.1416940 secs] 163923K->82003K(228964K), 0.1472180 secs]
 25.439: [GC 25.440: [DefNew: 0K->0K(16448K), 0.0035490 secs]25.443: [Tenured: 163923K->163923K(218596K), 0.0185150 secs] 163923K->163923K(235044K), 0.0244940 secs]
 25.464: [Full GC 25.464: [Tenured: 163923K->163922K(241984K), 0.2279020 secs] 163923K->163922K(260160K), [Perm : 983K->983K(65536K)], 0.2289560 secs]

EX) -verbose:gc -Xloggc:./gclog.log -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC

 25.217: [GC  {Heap before GC invocations=7:
 Heap
  def new generation   total 16448K, used 0K [0x9f720000, 0xa08f0000, 0xa0ad0000)
   eden space 14656K,   0% used [0x9f720000, 0x9f720000, 0xa0570000)
   from space 1792K,   0% used [0xa0570000, 0xa0570000, 0xa0730000)
   to   space 1792K,   0% used [0xa0730000, 0xa0730000, 0xa08f0000)
  tenured generation   total 218596K, used 163923K [0xa0ad0000, 0xae049000, 0xaf720000)
    the space 218596K,  74% used [0xa0ad0000, 0xaaae4c70, 0xaaae4e00, 0xae049000)
  compacting perm gen  total 65536K, used 983K [0xaf720000, 0xb3720000, 0xb3720000)
    the space 65536K,   1% used [0xaf720000, 0xaf815c78, 0xaf815e00, 0xb3720000)
 25.217: [DefNew: 0K->0K(16448K), 0.0035860 secs]25.221: [Tenured: 163923K->163923K(218596K), 0.0202250 secs] 163923K->163923K(235044K) Heap after GC invocations=8:
 Heap
  def new generation   total 18176K, used 0K [0x9f720000, 0xa0ad0000, 0xa0ad0000)
   eden space 16192K,   0% used [0x9f720000, 0x9f720000, 0xa06f0000)
   from space 1984K,   0% used [0xa06f0000, 0xa06f0000, 0xa08e0000)
   to   space 1984K,   0% used [0xa08e0000, 0xa08e0000, 0xa0ad0000)
  tenured generation   total 241984K, used 163923K [0xa0ad0000, 0xaf720000, 0xaf720000)
    the space 241984K,  67% used [0xa0ad0000, 0xaaae4c70, 0xaaae4e00, 0xaf720000)
  compacting perm gen  total 65536K, used 983K [0xaf720000, 0xb3720000, 0xb3720000)
    the space 65536K,   1% used [0xaf720000, 0xaf815c78, 0xaf815e00, 0xb3720000)
 } , 0.0260100 secs]
 25.243: [Full GC  {Heap before GC invocations=8:
 Heap
  def new generation   total 18176K, used 0K [0x9f720000, 0xa0ad0000, 0xa0ad0000)
   eden space 16192K,   0% used [0x9f720000, 0x9f720000, 0xa06f0000)
   from space 1984K,   0% used [0xa06f0000, 0xa06f0000, 0xa08e0000)
   to   space 1984K,   0% used [0xa08e0000, 0xa08e0000, 0xa0ad0000)
  tenured generation   total 241984K, used 163923K [0xa0ad0000, 0xaf720000, 0xaf720000)
    the space 241984K,  67% used [0xa0ad0000, 0xaaae4c70, 0xaaae4e00, 0xaf720000)
  compacting perm gen  total 65536K, used 983K [0xaf720000, 0xb3720000, 0xb3720000)
    the space 65536K,   1% used [0xaf720000, 0xaf815c78, 0xaf815e00, 0xb3720000)
 25.243: [Tenured: 163923K->163922K(241984K), 0.2528490 secs] 163923K->163922K(260160K), [Perm : 983K->983K(65536K)] Heap after GC invocations=9:
 Heap
  def new generation   total 18176K, used 0K [0x9f720000, 0xa0ad0000, 0xa0ad0000)
   eden space 16192K,   0% used [0x9f720000, 0x9f720000, 0xa06f0000)
   from space 1984K,   0% used [0xa06f0000, 0xa06f0000, 0xa08e0000)
   to   space 1984K,   0% used [0xa08e0000, 0xa08e0000, 0xa0ad0000)
  tenured generation   total 241984K, used 163922K [0xa0ad0000, 0xaf720000, 0xaf720000)
    the space 241984K,  67% used [0xa0ad0000, 0xaaae4b00, 0xaaae4c00, 0xaf720000)
  compacting perm gen  total 65536K, used 983K [0xaf720000, 0xb3720000, 0xb3720000)
    the space 65536K,   1% used [0xaf720000, 0xaf815c78, 0xaf815e00, 0xb3720000)
 } , 0.2534500 secs]

EX) -verbose:gc -Xloggc:./gclog.log -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution

22.899: [DefNew
Desired survivor size 229376 bytes, new threshold 31 (max 31)
- age   1:         96 bytes,         96 total
- age   3:      84976 bytes,      85072 total
: 2644K->83K(4544K), 0.0020960 secs]22.901: [Tenured: 55040K->20563K(60544K), 0.0450150 secs] 57684K->20563K(65088K) Heap after GC invocations=3:
Heap
 def new generation   total 4608K, used 0K [0x9f7a0000, 0x9fc90000, 0xa0b50000)
  eden space 4160K,   0% used [0x9f7a0000, 0x9f7a0000, 0x9fbb0000)
  from space 448K,   0% used [0x9fbb0000, 0x9fbb0000, 0x9fc20000)
  to   space 448K,   0% used [0x9fc20000, 0x9fc20000, 0x9fc90000)
 tenured generation   total 60544K, used 20563K [0xa0b50000, 0xa4670000, 0xaf7a0000)
   the space 60544K,  33% used [0xa0b50000, 0xa1f64c60, 0xa1f64e00, 0xa4670000)
 compacting perm gen  total 65536K, used 983K [0xaf7a0000, 0xb37a0000, 0xb37a0000)
   the space 65536K,   1% used [0xaf7a0000, 0xaf895e08, 0xaf896000, 0xb37a0000)
} , 0.0480610 secs]
23.005: [GC  {Heap before GC invocations=3:
Heap
 def new generation   total 4608K, used 0K [0x9f7a0000, 0x9fc90000, 0xa0b50000)
  eden space 4160K,   0% used [0x9f7a0000, 0x9f7a0000, 0x9fbb0000)
  from space 448K,   0% used [0x9fbb0000, 0x9fbb0000, 0x9fc20000)
  to   space 448K,   0% used [0x9fc20000, 0x9fc20000, 0x9fc90000)
 tenured generation   total 60544K, used 41043K [0xa0b50000, 0xa4670000, 0xaf7a0000)
   the space 60544K,  67% used [0xa0b50000, 0xa3364c70, 0xa3364e00, 0xa4670000)
 compacting perm gen  total 65536K, used 983K [0xaf7a0000, 0xb37a0000, 0xb37a0000)
   the space 65536K,   1% used [0xaf7a0000, 0xaf895e08, 0xaf896000, 0xb37a0000)
23.005: [DefNew
Desired survivor size 229376 bytes, new threshold 31 (max 31)
: 0K->0K(4608K), 0.0018680 secs]23.007: [Tenured: 41043K->41043K(60544K), 0.0155750 secs] 41043K->41043K(65152K) Heap after GC invocations=4:
Heap
 def new generation   total 5184K, used 0K [0x9f7a0000, 0x9fd40000, 0xa0b50000)
  eden space 4608K,   0% used [0x9f7a0000, 0x9f7a0000, 0x9fc20000)
  from space 576K,   0% used [0x9fc20000, 0x9fc20000, 0x9fcb0000)
  to   space 576K,   0% used [0x9fcb0000, 0x9fcb0000, 0x9fd40000)
 tenured generation   total 68408K, used 41043K [0xa0b50000, 0xa4e1e000, 0xaf7a0000)
   the space 68408K,  59% used [0xa0b50000, 0xa3364c70, 0xa3364e00, 0xa4e1e000)
 compacting perm gen  total 65536K, used 983K [0xaf7a0000, 0xb37a0000, 0xb37a0000)
   the space 65536K,   1% used [0xaf7a0000, 0xaf895e08, 0xaf896000, 0xb37a0000)
} , 0.0188350 secs]

1.5는 좀더 자세함. - Perm gen의 shared-ro와 shared-rw 이해안감.

# Perm Gen [shared-ro]: read-only reflective data
# Perm Gen [shared-rw]: read-write reflective data

28.735: [GC {Heap before gc invocations=13:
 def new generation   total 16448K, used 0K [0x7c9b0000, 0x7db80000, 0x7dd60000)
  eden space 14656K,   0% used [0x7c9b0000, 0x7c9b0000, 0x7d800000)
  from space 1792K,   0% used [0x7d9c0000, 0x7d9c0000, 0x7db80000)
  to   space 1792K,   0% used [0x7d800000, 0x7d800000, 0x7d9c0000)
 tenured generation   total 218632K, used 163942K [0x7dd60000, 0x8b2e2000, 0x8c9b0000)
   the space 218632K,  74% used [0x7dd60000, 0x87d79b40, 0x87d79c00, 0x8b2e2000)
 compacting perm gen  total 65536K, used 22K [0x8c9b0000, 0x909b0000, 0x909b0000)
   the space 65536K,   0% used [0x8c9b0000, 0x8c9b59b0, 0x8c9b5a00, 0x909b0000)
    ro space 8192K,  68% used [0x909b0000, 0x90f33660, 0x90f33800, 0x911b0000)
    rw space 12288K,  48% used [0x911b0000, 0x91782408, 0x91782600, 0x91db0000)
28.735: [DefNew
Desired survivor size 917504 bytes, new threshold 15 (max 15)
: 0K->0K(16448K), 0.0042840 secs]28.741: [Tenured: 163942K->163942K(218632K), 0.0196940 secs] 163942K->163942K(235080K)Heap after gc invocations=14:
 def new generation   total 18176K, used 0K [0x7c9b0000, 0x7dd60000, 0x7dd60000)
  eden space 16192K,   0% used [0x7c9b0000, 0x7c9b0000, 0x7d980000)
  from space 1984K,   0% used [0x7d980000, 0x7d980000, 0x7db70000)
  to   space 1984K,   0% used [0x7db70000, 0x7db70000, 0x7dd60000)
 tenured generation   total 241984K, used 163942K [0x7dd60000, 0x8c9b0000, 0x8c9b0000)
   the space 241984K,  67% used [0x7dd60000, 0x87d79b40, 0x87d79c00, 0x8c9b0000)
 compacting perm gen  total 65536K, used 22K [0x8c9b0000, 0x909b0000, 0x909b0000)
   the space 65536K,   0% used [0x8c9b0000, 0x8c9b59b0, 0x8c9b5a00, 0x909b0000)
    ro space 8192K,  68% used [0x909b0000, 0x90f33660, 0x90f33800, 0x911b0000)
    rw space 12288K,  48% used [0x911b0000, 0x91782408, 0x91782600, 0x91db0000)
}
, 0.0289380 secs]
28.764: [Full GC {Heap before gc invocations=14:
 def new generation   total 18176K, used 0K [0x7c9b0000, 0x7dd60000, 0x7dd60000)
  eden space 16192K,   0% used [0x7c9b0000, 0x7c9b0000, 0x7d980000)
  from space 1984K,   0% used [0x7d980000, 0x7d980000, 0x7db70000)
  to   space 1984K,   0% used [0x7db70000, 0x7db70000, 0x7dd60000)
 tenured generation   total 241984K, used 163942K [0x7dd60000, 0x8c9b0000, 0x8c9b0000)
   the space 241984K,  67% used [0x7dd60000, 0x87d79b40, 0x87d79c00, 0x8c9b0000)
 compacting perm gen  total 65536K, used 22K [0x8c9b0000, 0x909b0000, 0x909b0000)
   the space 65536K,   0% used [0x8c9b0000, 0x8c9b59b0, 0x8c9b5a00, 0x909b0000)
    ro space 8192K,  68% used [0x909b0000, 0x90f33660, 0x90f33800, 0x911b0000)
    rw space 12288K,  48% used [0x911b0000, 0x91782408, 0x91782600, 0x91db0000)
28.764: [Tenured: 163942K->163941K(241984K), 0.2293520 secs] 163942K->163941K(260160K), [Perm : 22K->21K(65536K)]Heap after gc invocations=15:
 def new generation   total 18176K, used 0K [0x7c9b0000, 0x7dd60000, 0x7dd60000)
  eden space 16192K,   0% used [0x7c9b0000, 0x7c9b0000, 0x7d980000)
  from space 1984K,   0% used [0x7d980000, 0x7d980000, 0x7db70000)
  to   space 1984K,   0% used [0x7db70000, 0x7db70000, 0x7dd60000)
 tenured generation   total 241984K, used 163941K [0x7dd60000, 0x8c9b0000, 0x8c9b0000)
   the space 241984K,  67% used [0x7dd60000, 0x87d79498, 0x87d79600, 0x8c9b0000)
 compacting perm gen  total 65536K, used 21K [0x8c9b0000, 0x909b0000, 0x909b0000)
   the space 65536K,   0% used [0x8c9b0000, 0x8c9b57d0, 0x8c9b5800, 0x909b0000)
    ro space 8192K,  68% used [0x909b0000, 0x90f33660, 0x90f33800, 0x911b0000)
    rw space 12288K,  48% used [0x911b0000, 0x91782408, 0x91782600, 0x91db0000)

Sun homepage의 예제
    -verbose:gc
      [GC 325407K->83000K(776768K), 0.2300771 secs]
      [GC 325816K->83372K(776768K), 0.2454258 secs]
      [Full GC 267628K->83769K(776768K), 1.8479984 secs]
     
    -verbose:gc -XX:+PrintGCDetails
      [GC [DefNew: 64575K->959K(64576K), 0.0457646 secs] 196016K->133633K(261184K), 0.0459067 secs]]
   
    -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps
        111.042: [GC 111.042: [DefNew: 8128K->8128K(8128K), 0.0000505 secs]111.042: [Tenured: 18154K->2311K(24576K), 0.1290354 secs] 26282K->2311K(32704K), 0.1293306 secs]








GC OUTPUT SAMPLE - Diagnosing a Garbage Collection problem
    : http://java.sun.com/docs/hotspot/gc1.4.2/example.html

FAQ - Frequently Asked Questions about Garbage Collection in the HotspotTM JavaTM Virtual Machine
    : http://java.sun.com/docs/hotspot/gc1.4.2/faq.html