1. 테스트 환경
- OS : CentOS
- JDK : 1.7 Update 67
- Tomcat : 7.0.55
- JBoss : 6.1 EAP
양 쪽 모두 메모리 옵션은 "-Xms1024m -Xmx1024m -MaxPermSize:256m"이며, JBoss 는 standalone.xml을 사용하였고, 동일하게 배포된 소스는 테스트 용 index.jsp 하나였습니다.
그리고 jmap -heap 결과로 비교합니다.
2. Tomcat
Debugger attached successfully. Server compiler detected. JVM version is 24.65-b04 using thread-local object allocation. Parallel GC with 1 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 1310720 (1.25MB) MaxNewSize = 17592186044415 MB OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 21757952 (20.75MB) MaxPermSize = 268435456 (256.0MB) G1HeapRegionSize = 0 (0.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 268959744 (256.5MB) used = 209978176 (200.25079345703125MB) free = 58981568 (56.24920654296875MB) 78.07048477856969% used From Space: capacity = 44564480 (42.5MB) used = 0 (0.0MB) free = 44564480 (42.5MB) 0.0% used To Space: capacity = 44564480 (42.5MB) used = 0 (0.0MB) free = 44564480 (42.5MB) 0.0% used PS Old Generation capacity = 716177408 (683.0MB) used = 0 (0.0MB) free = 716177408 (683.0MB) 0.0% used PS Perm Generation capacity = 22020096 (21.0MB) used = 15672144 (14.946121215820312MB) free = 6347952 (6.0538787841796875MB) 71.17200578962054% used 8838 interned Strings occupying 734576 bytes.
3. JBoss
Debugger attached successfully. Server compiler detected. JVM version is 24.65-b04 using thread-local object allocation. Parallel GC with 1 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 1310720 (1.25MB) MaxNewSize = 17592186044415 MB OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 21757952 (20.75MB) MaxPermSize = 268435456 (256.0MB) G1HeapRegionSize = 0 (0.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 268959744 (256.5MB) used = 242754536 (231.5087661743164MB) free = 26205208 (24.991233825683594MB) 90.25682891786215% used From Space: capacity = 44564480 (42.5MB) used = 22920656 (21.858840942382812MB) free = 21643824 (20.641159057617188MB) 51.432566923253674% used To Space: capacity = 44564480 (42.5MB) used = 0 (0.0MB) free = 44564480 (42.5MB) 0.0% used PS Old Generation capacity = 716177408 (683.0MB) used = 0 (0.0MB) free = 716177408 (683.0MB) 0.0% used PS Perm Generation capacity = 40370176 (38.5MB) used = 40199968 (38.337677001953125MB) free = 170208 (0.162322998046875MB) 99.57838182325487% used 14783 interned Strings occupying 1406320 bytes.