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From J Mohamed Zahoor <jmo...@gmail.com>
Subject Re: an emtry region
Date Fri, 10 Aug 2012 09:17:35 GMT
No. I just now learnt that compactions does not merge regions... (need to
verify this in code though).

./Zahoor

On Fri, Aug 10, 2012 at 2:43 PM, J Mohamed Zahoor <jmozah@gmail.com> wrote:

> Hi
>
> I think major compaction does this for you.
> But any way there is a utility called Merge which will merge adjoining
> Regions.
>
> more here http://hbase.apache.org/book/ops.regionmgt.html
>
> ./zahoor
>
>
> On Fri, Aug 10, 2012 at 1:47 PM, samar kumar <samar.opensource@gmail.com>wrote:
>
>> @Zahoor thanks
>> Looks good.. Is there a way to merge regions automatically??
>> Assuming there was a split and then lot of deletes on each region. Making
>> each region quite light weight can we merge those two regions to one
>> (automatically, like some kind of config)
>>
>> On 10/08/12 1:07 PM, "J Mohamed Zahoor" <jmozah@gmail.com> wrote:
>>
>> >Look at this post for more about Catalog Janitor
>> >
>> >http://blog.zahoor.in/2012/08/hbase-hmaster-architecture/
>> >
>> >On Fri, Aug 10, 2012 at 12:45 PM, J Mohamed Zahoor <jmozah@gmail.com>
>> >wrote:
>> >
>> >> Hi
>> >> Region don't remain for ever.
>> >> Catalog Janitor chore will scan for unused regions in the META and
>> >>garbage
>> >> collect. by default it is triggered every 300 sec. The property
>> >> "hbase.catalogjanitor.interval" is used for this.
>> >>
>> >> ./Zahoor
>> >>
>> >>
>> >> On Tue, Aug 7, 2012 at 4:44 PM, Anoop Sam John <anoopsj@huawei.com>
>> >>wrote:
>> >>
>> >>> Hi,
>> >>> >Now could I merge those two regions or automatically delete that
>> >>>region.
>> >>> There is no automatic deletion of regions which will happen within
>> >>>HBase.
>> >>> Yes u can write code which can do the merge of the 2 regions so that
>> >>>only
>> >>> one region will exists.
>> >>> Having more and more empty regions(unwanted region) is an overhead
>> >>>only.
>> >>>
>> >>> -Anoop-
>> >>> ________________________________________
>> >>> From: samar kumar [samar.opensource@gmail.com]
>> >>> Sent: Tuesday, August 07, 2012 4:32 PM
>> >>> To: user@hbase.apache.org
>> >>> Subject: Re: an emtry region
>> >>>
>> >>> @Syed Thanks for respond
>> >>>  Lets assume that we had a huge table which got split into two
>> regions.
>> >>> Later all the rows for that region was deleted. So now we have one
>> >>>table,
>> >>> two regions with the second region empty. Table could possible have
>> >>>more
>> >>> that one CF. also can't remove the CF because it is still relevant and
>> >>> data is present in the first region for that particular CF.
>> >>> Now could I merge those two regions or automatically delete that
>> >>>region.
>> >>> Samar
>> >>>
>> >>> On 07/08/12 4:19 PM, "syed kather" <in.abdul@gmail.com> wrote:
>> >>>
>> >>> > samar kumar,
>> >>> >
>> >>> >   If all the rows of an region are deleted what happens to the
>> >>>region.
>> >>> >Would it still exist .?
>> >>> > Yes it will exist . Whenever you create a family HBase will create
>> >>> >a separate Space for that Column Family . If there data available
for
>> >>> then
>> >>> >that data will be written to HFile which is create for that column
>> >>>family
>> >>> >space. If you need  to remove column family completely you have
a
>> >>>write
>> >>> >the separate code to handle this
>> >>> >
>> >>> >Also what is the cost of having a empty region?
>> >>> >I also don't have proper explanation for this
>> >>> >
>> >>> >
>> >>> >On Tue, Aug 7, 2012 at 4:03 PM, samar kumar
>> >>> ><samar.opensource@gmail.com>wrote:
>> >>> >
>> >>> >> Please read the subject as  "an empty region"
>> >>> >>
>> >>> >> From:  samar kumar <samar.opensource@gmail.com>
>> >>> >> Date:  Tue, 07 Aug 2012 15:57:04 +0530
>> >>> >> To:  "user@hbase.apache.org" <user@hbase.apache.org>
>> >>> >> Subject:  an emtry region
>> >>> >>
>> >>> >> Hi Hbase users,
>> >>> >> If all the rows of an region are deleted what happens to the
>> region.
>> >>> >>Would
>> >>> >> it still exist . It can be removed by writing some code but
can it
>> >>>be
>> >>> >> removed automatically. Also what is the cost of having a empty
>> >>>region.
>> >>> >> Regards,
>> >>> >> Samar
>> >>> >>
>> >>> >>
>> >>> >>
>> >>>
>> >>
>> >>
>>
>>
>>
>

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