java进程莫名的假死，调用jmap/jstack后恢复工作

Ray。Z 2016-05-13 10:30:47

使用java做一个项目，jdk版本为1.7.0_79，现发现程序在运行一段时间后，会莫名的处于假死状态（根据日志判断，正常情况下该程序会刷日志）；而当该进程处于假死状态后，调用jmap -heap pid 和 jstack -F pid 分析之后，该java进程又恢复正常工作，求大神帮忙分析一下问题原因。

这是当时执行jmap打印的信息：



[root@localhost root]# jmap -heap 32135

Attaching to process ID 32135, please wait...

Debugger attached successfully.

Server compiler detected.

JVM version is 24.79-b02



using thread-local object allocation.

Parallel GC with 18 thread(s)



Heap Configuration:

   MinHeapFreeRatio = 0

   MaxHeapFreeRatio = 100

   MaxHeapSize      = 4294967296 (4096.0MB)

   NewSize          = 1310720 (1.25MB)

   MaxNewSize       = 17592186044415 MB

   OldSize          = 5439488 (5.1875MB)

   NewRatio         = 2

   SurvivorRatio    = 8

   PermSize         = 21757952 (20.75MB)

   MaxPermSize      = 85983232 (82.0MB)

   G1HeapRegionSize = 0 (0.0MB)



Heap Usage:

PS Young Generation

Eden Space:

   capacity = 354418688 (338.0MB)

   used     = 341848280 (326.01192474365234MB)

   free     = 12570408 (11.988075256347656MB)

   96.45323217267821% used

From Space:

   capacity = 1572864 (1.5MB)

   used     = 1068480 (1.01898193359375MB)

   free     = 504384 (0.48101806640625MB)

   67.93212890625% used

To Space:

   capacity = 2621440 (2.5MB)

   used     = 0 (0.0MB)

   free     = 2621440 (2.5MB)

   0.0% used

PS Old Generation

   capacity = 75497472 (72.0MB)

   used     = 58251928 (55.553367614746094MB)

   free     = 17245544 (16.446632385253906MB)

   77.15745502048068% used

PS Perm Generation

   capacity = 46661632 (44.5MB)

   used     = 46353704 (44.206336975097656MB)

   free     = 307928 (0.29366302490234375MB)

   99.34008309010709% used



21330 interned Strings occupying 2260360 bytes.