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HBase >> mail # user >> more regionservers does not improve performance


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Re: more regionservers does not improve performance
I recommend turning on debug logging on your region servers.  You may need
to tune down certain packages back to info, because there are a few spammy
ones, but overall it helps.

You should see messages such as "12/10/09 14:22:57 INFO
regionserver.HRegion: Blocking updates for 'IPC Server handler 41 on 60020'
on region XXX: memstore size 256.0m is >= than blocking 256.0m size".  As
you can see, this is an INFO anyway so you should be able to see it now if
it is happening.

You can try upping the number of IPC handlers and the memstore flush
threshold.  Also, maybe you are bottlenecked by the WAL.  Try doing
put.setWriteToWAL(false), just to see if it increases performance.  If so
and you want to be a bit more safe with regard to the wal, you can try
turning on deferred flush on your table.  I don't really know how to
increase performance of the wal aside from that, if this does seem to have
an affect.

On Fri, Oct 12, 2012 at 3:15 PM, Jonathan Bishop <[EMAIL PROTECTED]>wrote:

> Kevin,
>
> Sorry, I am fairly new to HBase. Can you be specific about what settings I
> can change, and also where they are specified?
>
> Pretty sure I am not hotspotting, and increasing memstore does not seem to
> have any effect.
>
> I do not seen any messages in my regionserver logs concerning blocking.
>
> I am suspecting that I am hitting some limit in our grid, but would like to
> know where that limit is being imposed.
>
> Jon
>
> On Fri, Oct 12, 2012 at 6:44 AM, Kevin O'dell <[EMAIL PROTECTED]
> >wrote:
>
> > Jonathan,
> >
> >   Lets take a deeper look here.
> >
> > What is your memstore set at for the table/CF in question?  Lets compare
> > that value with the flush size you are seeing for your regions.  If they
> > are really small flushes is it all to the same region?  If so that is
> going
> > to be schema issues.  If they are full flushes you can up your memstore
> > assuming you have the heap to cover it.  If they are smaller flushes but
> to
> > different regions you most likely are suffering from global limit
> pressure
> > and flushing too soon.
> >
> > Are you flushing prematurely due to HLogs rolling?  Take a look for too
> > many hlogs and look at the flushes.  It may benefit you to raise that
> > value.
> >
> > Are you blocking?  As Suraj was saying you may be blocking in 90second
> > blocks.  Check the RS logs for those messages as well and then Suraj's
> > advice.
> >
> > This is where I would start to optimize your write path.  I hope the
> above
> > helps.
> >
> > On Fri, Oct 12, 2012 at 3:34 AM, Suraj Varma <[EMAIL PROTECTED]>
> wrote:
> >
> > > What have you configured your hbase.hstore.blockingStoreFiles and
> > > hbase.hregion.memstore.block.multiplier? Both of these block updates
> > > when the limit is hit. Try increasing these to say 20 and 4 from the
> > > default 7 and 2 and see if it helps.
> > >
> > > If this still doesn't help, see if you can set up ganglia to get a
> > > better insight into what is bottlenecking.
> > > --Suraj
> > >
> > >
> > >
> > > On Thu, Oct 11, 2012 at 11:47 PM, Pankaj Misra
> > > <[EMAIL PROTECTED]> wrote:
> > > > OK, Looks like I missed out reading that part in your original mail.
> > Did
> > > you try some of the compaction tweaks and configurations as explained
> in
> > > the following link for your data?
> > > > http://hbase.apache.org/book/regions.arch.html#compaction
> > > >
> > > >
> > > > Also, how much data are your putting into the regions, and how big is
> > > one region at the end of data ingestion?
> > > >
> > > > Thanks and Regards
> > > > Pankaj Misra
> > > >
> > > > -----Original Message-----
> > > > From: Jonathan Bishop [mailto:[EMAIL PROTECTED]]
> > > > Sent: Friday, October 12, 2012 12:04 PM
> > > > To: [EMAIL PROTECTED]
> > > > Subject: RE: more regionservers does not improve performance
> > > >
> > > > Pankaj,
> > > >
> > > > Thanks  for the reply.
> > > >
> > > > Actually, I am using MD5 hashing to evenly spread the keys among the
> > > splits, so I don’t believe there is any hotspot. In fact, when I
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB