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HBase >> mail # user >> Unbalanced region server


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David Charle 2012-04-24, 01:41
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Bryan Beaudreault 2012-04-24, 02:50
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David Charle 2012-04-24, 03:03
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Re: Unbalanced region server
Does balancer_switch=true; rebalances any skew in the existing keys or it
only does for all new regions ? The requests seems to be oK across all
servers.

On Mon, Apr 23, 2012 at 8:03 PM, David Charle <[EMAIL PROTECTED]> wrote:

> Thanks Bryan.
>
> Here is the regions count:
>
> 1: 2616
> 2: 2620
> 3: 2623
> 4: 2617
> 5: 2617
>
> The skew is in Node 2 where we have the space issue (double the size of
> other 4 nodes).
>
>
> On Mon, Apr 23, 2012 at 7:50 PM, Bryan Beaudreault <
> [EMAIL PROTECTED]> wrote:
>
>> 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
>> >
>>
>
>
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Bryan Beaudreault 2012-04-24, 03:43
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David Charle 2012-04-24, 04:07
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Bryan Beaudreault 2012-04-24, 04:14
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Stack 2012-04-24, 04:13