Can you paste you gc config? Also can you take a heap dump at 2 diff points so 
that we can compare it?

Quick thing to do would be to do a histo live at 2 points and compare

Sent from my iPhone

On Jun 15, 2013, at 6:57 AM, Takenori Sato <ts...@cloudian.com> wrote:

> > INFO [ScheduledTasks:1] 2013-04-15 14:00:02,749 GCInspector.java (line 122) 
> > GC for ParNew: 338798 ms for 1 collections, 592212416 used; max is 
> > 1046937600
> 
> This says GC for New Generation took so long. And this is usually unlikely. 
> 
> The only situation I am aware of is when a fairly large object is created, 
> and which can not be promoted to Old Generation because it requires such a 
> large *contiguous* memory space that is unavailable at the point in time. 
> This is called promotion failure. So it has to wait until concurrent 
> collector collects a large enough space. Thus you experience stop the world. 
> But I think it is not stop the world, but only stop the new world.
> 
> For example in case of Cassandra, a large number of 
> in_memory_compaction_limit_in_mb can cause this. This is a limit when a 
> compaction compacts(merges) rows of a key into the latest in memory. So this 
> creates a large byte array up to the number.
> 
> You can confirm this by enabling promotion failure GC logging in the future, 
> and by checking compactions executed at that point in time.
> 
> 
> 
> On Sat, Jun 15, 2013 at 10:01 AM, Robert Coli <rc...@eventbrite.com> wrote:
>> On Fri, Jun 7, 2013 at 12:42 PM, Igor <i...@4friends.od.ua> wrote:
>> > If you are talking about 1.2.x then I also have memory problems on the idle
>> > cluster: java memory constantly slow grows up to limit, then spend long 
>> > time
>> > for GC. I never seen such behaviour for 1.0.x and 1.1.x, where on idle
>> > cluster java memory stay on the same value.
>> 
>> If you are not aware of a pre-existing JIRA, I strongly encourage you to :
>> 
>> 1) Document your experience of this.
>> 2) Search issues.apache.org for anything that sounds similar.
>> 3) If you are unable to find a JIRA, file one.
>> 
>> Thanks!
>> 
>> =Rob
> 

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