jvm内存问题

Question

Heap Configuration:
   MinHeapFreeRatio         = 0
   MaxHeapFreeRatio         = 100
   MaxHeapSize              = 2065694720 (1970.0MB)
   NewSize                  = 42991616 (41.0MB)
   MaxNewSize               = 688390144 (656.5MB)
   OldSize                  = 87031808 (83.0MB)
   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 = 565182464 (539.0MB)
   used     = 466991056 (445.3573760986328MB)
   free     = 98191408 (93.64262390136719MB)
   82.62660038935674% used
From Space:
   capacity = 16777216 (16.0MB)
   used     = 16457416 (15.695014953613281MB)
   free     = 319800 (0.30498504638671875MB)
   98.09384346008301% used
To Space:
   capacity = 17301504 (16.5MB)
   used     = 0 (0.0MB)
   free     = 17301504 (16.5MB)
   0.0% used
PS Old Generation
   capacity = 192413696 (183.5MB)
   used     = 97096400 (92.59834289550781MB)
   free     = 95317296 (90.90165710449219MB)
   50.46231220463641% used

jmap -heap pid查看的

NewRatio为2，但是eden space为500多M,老年代才 183M

Answer 1

NewRatio = 2 代表新生代跟老年代的比例是1:2，SurvivorRatio=8 表示 两个Survivor ： Eden = 2： 8 ，这个应该是默认的吧？并且就是这两个值，但是实际没有按照这个比例来划分

Answer 2

你这个应该是没固定配置值的吧，动态变化的，给你看个我的

Heap Configuration:
   MinHeapFreeRatio         = 0
   MaxHeapFreeRatio         = 100
   MaxHeapSize              = 536870912 (512.0MB)
   NewSize                  = 178782208 (170.5MB)
   MaxNewSize               = 178782208 (170.5MB)
   OldSize                  = 358088704 (341.5MB)
   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 = 80740352 (77.0MB)
   used     = 30077800 (28.684425354003906MB)
   free     = 50662552 (48.315574645996094MB)
   37.252500459745335% used
From Space:
   capacity = 30932992 (29.5MB)
   used     = 30741064 (29.31696319580078MB)
   free     = 191928 (0.18303680419921875MB)
   99.3795362569518% used
To Space:
   capacity = 49283072 (47.0MB)
   used     = 0 (0.0MB)
   free     = 49283072 (47.0MB)
   0.0% used
PS Old Generation
   capacity = 358088704 (341.5MB)
   used     = 43572856 (41.55431365966797MB)
   free     = 314515848 (299.94568634033203MB)
   12.1681738388486% used