Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase, mail # user - Struggling with Region Servers Running out of Memory


Copy link to this message
-
Re: Struggling with Region Servers Running out of Memory
Stack 2012-10-31, 05:39
On Mon, Oct 29, 2012 at 3:55 PM, Jeff Whiting <[EMAIL PROTECTED]> 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
> [EMAIL PROTECTED]
>