Can you try running this with CMS GC instead of G1GC? G1 still has some
bugs... 64M sounds like it might be G1 "regions"?

-Todd

On Thu, Nov 11, 2010 at 2:07 AM, Friso van Vollenhoven <
[email protected]> wrote:

> Hi All,
>
> (This is all about CDH3, so I am not sure whether it should go on this
> list, but I figure it is at least interesting for people trying the same.)
>
> I've recently tried CDH3 on a new cluster from RPMs with the hadoop-lzo
> fork from https://github.com/toddlipcon/hadoop-lzo. Everything works like
> a charm initially, but after some time (minutes to max one hour), the RS JVM
> process memory grows to more than twice the given heap size and beyond. I
> have seen a RS with 16GB heap that grows to 55GB virtual size. At some
> point, everything start swapping and GC times go into the minutes and
> everything dies or is considered dead by the master.
>
> I did a pmap -x on the RS process and that shows a lot of allocated blocks
> of about 64M by the process. There about 500 of these, which is 32GB in
> total. See: http://pastebin.com/8pgzPf7b (bottom of the file, the blocks
> of about 1M on top are probably thread stacks). Unfortunately, Linux shows
> the native heap as anon blocks, so I can not link it to a specific lib or
> something.
>
> I am running the latest CDH3 and hadoop-lzo 0.4.6 (from said URL, the one
> which has the reinit() support). I run Java 6u21 with the G1 garbage
> collector, which has been running fine for some weeks now. Full command line
> is:
> java -Xmx16000m -XX:+HeapDumpOnOutOfMemoryError
> -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:+UseCompressedOops
> -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps
> -Xloggc:/export/logs/hbase/gc-hbase.log
> -Djava.library.path=/home/inr/java-lib/hbase/native/Linux-amd64-64
> -Djava.net.preferIPv4Stack=true -Dhbase.log.dir=/export/logs/hbase
> -Dhbase.log.file=hbase-hbase-regionserver-w3r1.inrdb.ripe.net.log
> -Dhbase.home.dir=/usr/lib/hbase/bin/.. -Dhbase.id.str=hbase -Dhbase.r
>
> I searched the HBase source for something that could point to native heap
> usage (like ByteBuffer#allocateDirect(...)), but I could not find anything.
> Thread count is about 185 (I have 100 handlers), so nothing strange there as
> well.
>
> Question is, could this be HBase or is this a problem with the hadoop-lzo?
>
> I have currently downgraded to a version known to work, because we have a
> demo coming up. But still interested in the answer.
>
>
>
> Regards,
> Friso
>
>


-- 
Todd Lipcon
Software Engineer, Cloudera

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