服务器上某应用cpu一直100%问题记录

   jstack 31066 |grep 'nid=795A'

 

用jmap -heap pid 查看内存使用情况（可以观察到New Generation（Eden Space，From Space，To Space）,tenured generation,Perm Generation的内存使用情况），数据如下：

 

Attaching to process ID 6736, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 20.1-b02

using thread-local object allocation.
Parallel GC with 18 thread(s)

Heap Configuration:
   MinHeapFreeRatio = 40
   MaxHeapFreeRatio = 70
   MaxHeapSize      = 1073741824 (1024.0MB)
   NewSize          = 1310720 (1.25MB)
   MaxNewSize       = 17592186044415 MB
   OldSize          = 5439488 (5.1875MB)
   NewRatio         = 2
   SurvivorRatio    = 8
   PermSize         = 1073741824 (1024.0MB)
   MaxPermSize      = 1073741824 (1024.0MB)

Heap Usage:
PS Young Generation
Eden Space:
   capacity = 167968768 (160.1875MB)
   used     = 167968768 (160.1875MB)
   free     = 0 (0.0MB)
   100.0% used
From Space:
   capacity = 72548352 (69.1875MB)
   used     = 0 (0.0MB)
   free     = 72548352 (69.1875MB)
   0.0% used
To Space:
   capacity = 99221504 (94.625MB)
   used     = 0 (0.0MB)
   free     = 99221504 (94.625MB)
   0.0% used
PS Old Generation
   capacity = 715849728 (682.6875MB)
   used     = 715849608 (682.687385559082MB)
   free     = 120 (1.1444091796875E-4MB)
   99.99998323670523% used
PS Perm Generation
   capacity = 1073741824 (1024.0MB)
   used     = 84353312 (80.44558715820312MB)
   free     = 989388512 (943.5544128417969MB)
   7.856014370918274% used

 

从上面可以看出：Eden Space 使用率为100.0%，PS Old Generation 使用率为99.99998323670523%  

 

以上是内存的占用情况。

--------------------------------------------可恶的分割线---------------------------------------------

根据http://longtask.com/Java/2011/10/26/slave-java-cpu100-problem/  查看的最耗时线程信息如下：

 

 

"VM Thread" prio=10 tid=0x0000000040192800 nid=0x1a64 runnable 

 

 

 

 最后内存溢出了：

 

Caused by: java.lang.IllegalStateException: this writer hit an OutOfMemoryError; cannot flush