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HBase >> mail # user >> Unbalanced region server


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Re: Unbalanced region server
Do all nodes have the same number of regions?  If not you may not have the
balancer on.  You can turn it on using balancer_switch true in the hbase
shell.  The balancer also doesn't run if there is a region stuck in
transition.  In this case if your data is growing rapidly I have seen
regionservers become lopsided until I could clean up the stuck region and
re-enable the balancer.

Finally, depending on your version of hbase, the balancer only tries to
keep the number of regions similar across all regionservers.  If you have
tables of different max region sizes I could imagine a case where one
region server unluckily is hosting more regions from the table with larger
region sizes.  This also might explain the imbalance in requests, if one of
your tables gets more traffic than other.  The HMaster UI would be helpful
for determining the spread of regions per table across regionservers.

On Mon, Apr 23, 2012 at 9:41 PM, David Charle <[EMAIL PROTECTED]> wrote:

> Hi
>
> What can make a region server unbalanced when it comes to space ? (and
> possibly requests too).
>
> For example; I have 5 node cluster (replication factor of 3); and in which
> all 4 has same size; where as one node is almost double in size for /hbase.
>
> Any help will be appreciated; esp what makes the skew and how to fix it ?
>
> Thanks
> David
>