顯示堆棧信息
jmap -heap 41565 > ~/jmap.txt
堆大小排序
jmap -histo:live 41565 > ~/jmap.txt
打印線程堆棧
jmap -dump:format=b,file=/data/log/debug/pprof/heap.bin javapid
定時打印JVM內存信息
jstat -gcutil 4007 2000
S0: Survivor space 0 utilization as a percentage of the space's current capacity. 倖存者區0
S1: Survivor space 1 utilization as a percentage of the space's current capacity. 倖存者區1
E: Eden space utilization as a percentage of the space's current capacity. 伊甸園區
O: Old space utilization as a percentage of the space's current capacity. 老年代
M: Metaspace utilization as a percentage of the space's current capacity. 元空間
CCS: Compressed class space utilization as a percentage. 壓縮類空間利用率爲百分比。
YGC: Number of young generation GC events. 年輕一代GC事件的數量。
YGCT: Young generation garbage collection time. 年輕一代垃圾收集時間
FGC: Number of full GC events. 完整的GC事件的數量。
FGCT: Full garbage collection time. 完全垃圾收集時間。
GCT: Total garbage collection time. 垃圾回收總時間。