1、jps: 查看java进程
[root@VM-100-3-centos ~]# jps
7088 Jps
1521 ruoyi-admin.jar
3978 sys_perf_01-0.0.1-SNAPSHOT.jar
[root@VM-100-3-centos ~]#
2、jmap: 查看java内存
[root@VM-100-3-centos ~]# jmap -heap 3978
Attaching to process ID 3978, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.381-b09
using thread-local object allocation.
Parallel GC with 4 thread(s)
Heap Configuration:
MinHeapFreeRatio = 0
MaxHeapFreeRatio = 100
MaxHeapSize = 1258291200 (1200.0MB)
NewSize = 42467328 (40.5MB)
MaxNewSize = 419430400 (400.0MB)
OldSize = 85458944 (81.5MB)
NewRatio = 2
SurvivorRatio = 8
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 17592186044415 MB
G1HeapRegionSize = 0 (0.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 191365120 (182.5MB)
used = 76968480 (73.40286254882812MB)
free = 114396640 (109.09713745117188MB)
40.220746602097606% used
From Space:
capacity = 7864320 (7.5MB)
used = 7667760 (7.3125457763671875MB)
free = 196560 (0.1874542236328125MB)
97.5006103515625% used
To Space:
capacity = 11534336 (11.0MB)
used = 0 (0.0MB)
free = 11534336 (11.0MB)
0.0% used
PS Old Generation
capacity = 63438848 (60.5MB)
used = 11229000 (10.708808898925781MB)
free = 52209848 (49.79119110107422MB)
17.70051057673683% used
13102 interned Strings occupying 1125712 bytes.
[root@VM-100-3-centos ~]#
可以看到最大堆内存:MaxHeapSize = 1258291200 (1200.0MB)
这个数值是启动该java 服务时设置的最大内存,如下所示:
java -Xmx1200m -Dserver.port=18001 -jar sys_perf_01-0.0.1-SNAPSHOT.jar