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HBase >> mail # user >> Is there any way to balance one table?


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Re: Is there any way to balance one table?
bq. Don't go too low else it will never stop balancing the table each 5
minutes.

That shouldn't happen - balancer will stop if the difference between
highest number of regions and lowest becomes 1.

Cheers

On Wed, Feb 20, 2013 at 4:19 AM, Jean-Marc Spaggiari <
[EMAIL PROTECTED]> wrote:

> Hi Raymond,
>
> Yes, tables are balanced on by one. Balancer is taking one table,
> looking if it's already balancer or not, do the required move if any
> is needed, and then move to the next table.
>
> In your example, average is 23.25. 20% is 4.65. So everything between
> 18.6 and 27.9 should be ok. So balancer should remove some regions for
> the 3rd server (19 i/30/23/21).
>
> If you want to have that more evenly balanced, reduce the
> hbase.regions.slop value to something lower, like 0.1 or even 0.05.
> Don't go too low else it will never stop balancing the table each 5
> minutes.
>
> JM
>
> 2013/2/20, Liu, Raymond <[EMAIL PROTECTED]>:
> > You mean slop is also base on per table?
> > Weird, then it should work for my case.... let me check again.
> >
> > Best Regards,
> > Raymond Liu
> >
> >>
> >> bq. On a 3000 region cluster
> >>
> >> Balancing is per-table. Meaning total number of regions doesn't come
> into
> >> play.
> >>
> >> On Tue, Feb 19, 2013 at 7:55 PM, Liu, Raymond <[EMAIL PROTECTED]>
> >> wrote:
> >>
> >> > Hmm, in order to have the 96 region table be balanced within 20% On a
> >> > 3000 region cluster when all other table is balanced.
> >> >
> >> > the slop will need to be around 20%/30, say 0.006? won't it be too
> >> > small?
> >> >
> >> > >
> >> > > Yes, Raymond.
> >> > > You should lower sloppiness.
> >> > >
> >> > > On Tue, Feb 19, 2013 at 7:48 PM, Liu, Raymond
> >> > > <[EMAIL PROTECTED]>
> >> > > wrote:
> >> > >
> >> > > > I mean region number is small.
> >> > > >
> >> > > > Overall I have say 3000 region on 4 node, while this table only
> >> > > > have
> >> > > > 96 region. It won't be 24 for each region server, instead , will
> >> > > > be something like 19/30/23/21 etc.
> >> > > >
> >> > > > This means that I need to limit the slop to 0.02 etc? so that the
> >> > > > balancer actually run on this table?
> >> > > >
> >> > > > Best Regards,
> >> > > > Raymond Liu
> >> > > >
> >> > > > From: Marcos Ortiz [mailto:[EMAIL PROTECTED]]
> >> > > > Sent: Wednesday, February 20, 2013 11:44 AM
> >> > > > To: [EMAIL PROTECTED]
> >> > > > Cc: Liu, Raymond
> >> > > > Subject: Re: Is there any way to balance one table?
> >> > > >
> >> > > > What is the size of your table?
> >> > > > On 02/19/2013 10:40 PM, Liu, Raymond wrote:
> >> > > > Hi
> >> > > >
> >> > > > I do call balancer, while it seems it doesn't work. Might due to
> >> > > > this table is small and overall region number difference is within
> >> > threshold?
> >> > > >
> >> > > > -----Original Message-----
> >> > > > From: Jean-Marc Spaggiari [mailto:[EMAIL PROTECTED]]
> >> > > > Sent: Wednesday, February 20, 2013 10:59 AM
> >> > > > To: [EMAIL PROTECTED]
> >> > > > Subject: Re: Is there any way to balance one table?
> >> > > >
> >> > > > Hi Liu,
> >> > > >
> >> > > > Why did not you simply called the balancer? If other tables are
> >> > > > already balanced, it should not touch them and will only balance
> >> > > > the table which is not balancer?
> >> > > >
> >> > > > JM
> >> > > >
> >> > > > 2013/2/19, Liu, Raymond <[EMAIL PROTECTED]>:
> >> > > > I choose to move region manually. Any other approaching?
> >> > > >
> >> > > >
> >> > > > 0.94.1
> >> > > >
> >> > > > Any cmd in shell? Or I need to change balance threshold to 0 an
> >> > > > run global balancer cmd in shell?
> >> > > >
> >> > > >
> >> > > >
> >> > > > Best Regards,
> >> > > > Raymond Liu
> >> > > >
> >> > > > -----Original Message-----
> >> > > > From: Ted Yu [mailto:[EMAIL PROTECTED]]
> >> > > > Sent: Wednesday, February 20, 2013 9:09 AM
> >> > > > To: [EMAIL PROTECTED]
> >> > > > Subject: Re: Is there any way to balance one table?
> >> > > >
> >> > > > What version of HBase are you using ?