Good to know. Its nice they finally got that in. We aren't on u36 right now in production but I'm going to push on getting us there.

Thanks,
~Jeff

On 11/1/2012 11:07 AM, Jeremy Carroll wrote:
Java 6 update 34 can rotate GC Logs. -XX:+UseGCLogFileRotation

http://stackoverflow.com/questions/3822097/rolling-garbage-collector-logs-in-java

As for profiling memory dumps, jprofiler7, yourrkit, etc.. YMMV.


On Thu, Nov 1, 2012 at 10:01 AM, Jeff Whiting <je...@qualtrics.com> wrote:

We don't have GC logging enabled (we did but gc.log would begin filling up
the hdd and there was no way to clear it out without restarting the region
server).  Anyway to en gc.log and keep it to a reasonable size?

I have two separate jmap dumps of the a region server before it dies.  I
haven't really looked into those yet.  I'll try to do that today.  I've
typically used eclipse memory analyzer tool or netbeans.  Is there a
profiler you'd recommend?

~Jeff

On 10/30/2012 11:39 PM, Stack wrote:

On Mon, Oct 29, 2012 at 3:55 PM, Jeff Whiting <je...@qualtrics.com>
wrote:

However what we are seeing is that our memory usage goes up slowly until
the
region server starts sputtering due to gc collection issues and it will
eventually get timed out by zookeeper and be killed.

  Hey Jeff.  You have GC logging enabled?  Might not tell you more than
you already know, that something is retaining more and more objects
over time.   You have a dumped heap?  What have you used to poke at
it?  You generally want to find the objects that have the deepest size
(Not all profilers let you do this though).  This is usually enough to
give you a clue.

Anything particular about the character of your load?  Ram asks if any
big cells in the mix?

St.Ack




  At this point I feel somewhat lost as to how to debug the problem. I'm
not
sure what to do next to figure out what is going on.  Any suggestions as
to
what to look for or debug where the memory is being used? I can generate
heap dumps via jmap (although it effectively kills the region server)
but I
don't really know what to look for to see where the memory is going. I
also
have jmx setup on each region server and can connect to it that way.

Thanks,
~Jeff

--
Jeff Whiting
Qualtrics Senior Software Engineer
je...@qualtrics.com


--
Jeff Whiting
Qualtrics Senior Software Engineer
je...@qualtrics.com



--
Jeff Whiting
Qualtrics Senior Software Engineer
je...@qualtrics.com

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