Strange isssue about OOM

[Jon Masamitsu]

Steve,

The section 5.2.3 applies to the throughput collector (i.e., 
-XX:+UseParallelGC).  The snippet
of the gc log that you included does not look like a log from the 
throughput collector so
I don't think it is an issue of too much time spent in GC.

Jon

steve.zhuang at oocl.com wrote:
> avoid it?
>
> 3. We have studied JVM doc on
> http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html
> See: 5.2.3 Out-of-Memory Exceptions
> The throughput collector will throw an out-of-memory exception if too
> much time is being spent doing garbage collection. For example, if the
> JVM is spending more than 98% of the total time doing garbage collection
> and is recovering less than 2% of the heap, it will throw an
> out-of-memory expection. The implementation of this feature has changed
> in 1.5. The policy is the same but there may be slight differences in
> behavior due to the new implementation. 
>
> And our gc log:
> 25213.699: [GC 25213.699: [DefNew: 756K->82K(169600K), 0.0078670
> secs]25213.707: [Tenured[Unloading class
> sun.reflect.GeneratedConstructorAccessor274]
> : 226997K->221430K(349568K), 2.0173917 secs] 227753K->221430K(519168K),
> 2.0254397 secs]
> 25215.724: [Full GC 25215.724: [Tenured: 221430K->221422K(349568K),
> 1.2257687 secs] 221430K->221422K(519168K), [Perm :
> 27496K->27496K(65536K)], 1.2259138 secs]
>
> Seems our gc log reveals a behavior like "if the JVM is spending more
> than 98% of the total time doing garbage collection and is recovering
> less than 2% of the heap", is this the time server threw the OOM?
>
> Thanks.
>
> Best wishes,
> Steve Zhuang
>
>
>