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HBase, mail # user - Region balancing question


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Re: Region balancing question
Kevin O'dell 2012-08-02, 17:30
Bryan,

  https://issues.apache.org/jira/browse/HBASE-3373 did not make it into
CDH4, there is not a real easy way to do this on your own.  I have attached
some sample code to get your started with writing your own(a colleague of
mine wrote it).

On Thu, Aug 2, 2012 at 1:20 PM, Bryan Keller <[EMAIL PROTECTED]> wrote:

> I'm using 0.92 (Cloudera CDH4). Yes I definitely do not want to balance
> all regions across all tables together, as some tables are much more active
> than others and thus some regions are barely being used. I was thinking
> this might be what the balancer was doing. The regions are balanced in
> terms of total regions across all tables.
>
> Is there a way to change this behavior in 0.92?
>
> On Aug 2, 2012, at 2:54 AM, Anoop Sam John <[EMAIL PROTECTED]> wrote:
>
> > Hi
> >  Which version you are using?
> > From 0.94 in the balancer there are 2 ways of balancing. One is by table
> balancing in which balancer will make sure the regions for one table is
> balanced across the RSs. But in the other way of balancing in generic way
> it will consider all the regions across all the tables as one group only
> and will balance all across the RSs.  Seems the 2nd way is happening with
> ur case. Can u check the total number of regions (across all the tables) in
> every RS. Is this balanced now?
> >
> > "hbase.master.loadbalance.bytable" config param can select any of the 2
> ways of balancing. This is added in 0.94 version. You might be using some
> older version?
> >
> > -Anoop-
> > ________________________________________
> > From: Bryan Keller [[EMAIL PROTECTED]]
> > Sent: Thursday, August 02, 2012 11:37 AM
> > To: [EMAIL PROTECTED]
> > Subject: Region balancing question
> >
> > I have a table on a 4 node test cluster. I also have some other tables
> on the cluster. The table in question has a total of 12 regions. I noticed
> that 1 node has 6 regions, another has zero, and the remaining two nodes
> have the expected 3 regions. I'm a little confused how this can happen.
> >
> > The node with zero regions for the table has regions for other tables,
> so the node seems to be functioning properly. I'm not sure how this
> particular table can end up having no regions on this one node. Should the
> balancer distribute the regions evenly across the cluster for a given
> table? If so, is there a way to force it to rebalance?
>
>
--
Kevin O'Dell
Customer Operations Engineer, Cloudera