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HBase, mail # user - hbase-0.94.6.1 balancer issue


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Re: hbase-0.94.6.1 balancer issue
Samir Ahmic 2013-04-12, 16:37
Thanks for explaining Jean-Marc,

We are using 0.90.4 for very long time and balancing was based on total
number of regions.That is why i was surprised with balancer log on 0.94.
Well i'm more ops guy then dev i handle what other develop :)

Regards
On Fri, Apr 12, 2013 at 6:24 PM, Jean-Marc Spaggiari <
[EMAIL PROTECTED]> wrote:

> Hi Samir,
>
> Since regions are balanced per table, as soon as you will have more than
> one region in your table, balancer will start to balance the regions over
> the servers.
>
> You can split some of those tables and will you start to see HBase balance
> them. This is normal behavior for 0.94. I don't know for versions before
> that.
>
> Also, are you sure you need 48 tables? And not less tables with more CFs?
>
> JM
>
> 2013/4/12 Samir Ahmic <[EMAIL PROTECTED]>
>
> > Hi, JM
> >
> > I have 48 tables and as you said it is 1 region per table since i did not
> > reach splitting limit yet. So this is normal behavior  in 0.94.6.1
> version
> > ?  And at what point balancer will start redistribute regions to second
> > server ?
> >
> > Thanks
> > Samir
> >
> >
> > On Fri, Apr 12, 2013 at 6:06 PM, Jean-Marc Spaggiari <
> > [EMAIL PROTECTED]> wrote:
> >
> > > Hi Samir,
> > >
> > > Regions are balancer per table.
> > >
> > > So if you have 48 regions within the same table, it should be split
> about
> > > 24 on each server.
> > >
> > > But if you have 48 tables with 1 region each, the for each table, the
> > > balancer will see only 1 region and will display the message you saw.
> > >
> > > Have you looked at the UI? What do you have in it? Can you please
> confirm
> > > if yo uhave 48 tables or 1 table?
> > >
> > > Thanks,
> > >
> > > JM
> > >
> > >
> > > 2013/4/12 Samir Ahmic <[EMAIL PROTECTED]>
> > >
> > > > Hi, all
> > > >
> > > > I'm evaluating hbase-0.94.6.1 and i have 48 regions on 2 node
> cluster.
> > I
> > > > was restarting on of RSs and after that tried to balance cluster by
> > > running
> > > > balancer from shell. After running command regions were not
> distributed
> > > to
> > > > second RS and i found this line i master log:
> > > >
> > > > 2013-04-12 16:45:15,589 INFO
> > org.apache.hadoop.hbase.master.LoadBalancer:
> > > > Skipping load balancing because balanced cluster; servers=2
> *regions=1
> > > > *average=0.5
> > > > mostloaded=1 leastloaded=0
> > > >
> > > > This look like to me that wrong number of regions is reported by
> > balancer
> > > > and that cause of  skipping load balancing . In hbase shell i see all
> > 48
> > > > tables that i have and everything else looks fine.
> > > >
> > > > Did someone else see this type of behavior ? Did something changed
> > around
> > > > balancer in hbase-0.94.6.1 ?
> > > >
> > > > Regards
> > > > Samir
> > > >
> > >
> >
>