Question

我有一个2GB作为堆大小的服务器。当我从jstat收集JVM内存统计信息时，我发现次要GC几乎每隔一秒或每隔一秒发生一次。然后我看作jmap -heap输出，幸存者比率设置为8，伊甸园空间看起来是682.5MB，这是正确的newRatio = 2。根据我的计算，如果2GB堆的幸存率为8，则S0C和S1C应为68MB左右，但jmap输出仅显示1.5MB。有人可以解释为什么会发生这种情况

这是我的jmap -heap输出。

 Heap Configuration:
   MinHeapFreeRatio         = 0
   MaxHeapFreeRatio         = 100
   MaxHeapSize              = 2147483648 (2048.0MB)
   NewSize                  = 715653120 (682.5MB)
   MaxNewSize               = 715653120 (682.5MB)
   OldSize                  = 1431830528 (1365.5MB)
   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 = 712507392 (679.5MB)
   used     = 477707104 (455.5769958496094MB)
   free     = 234800288 (223.92300415039062MB)
   67.0459155039896% used
From Space:
   capacity = 1572864 (1.5MB)       ------ S0C
   used     = 786432 (0.75MB)
   free     = 786432 (0.75MB)
   50.0% used
To Space:
   capacity = 1572864 (1.5MB)       ------ S1C
   used     = 0 (0.0MB)
   free     = 1572864 (1.5MB)
   0.0% used
PS Old Generation
   capacity = 1431830528 (1365.5MB)
   used     = 779522880 (743.4109497070312MB)
   free     = 652307648 (622.0890502929688MB)
   54.442398367413496% used

幸存者空间大小在JMap中太小

0 个答案: