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Posted to user@hbase.apache.org by samar kumar <sa...@gmail.com> on 2012/08/07 12:27:04 UTC
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
Re: an emtry region
Posted by Harsh J <ha...@cloudera.com>.
You're right there - compactions does not merge region boundaries.
They just merge the accumulated (flushed, etc.) storefiles belonging
to each region, for every region thats fragmented over time.
On Fri, Aug 10, 2012 at 2:47 PM, J Mohamed Zahoor <jm...@gmail.com> wrote:
> 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 <jm...@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 <sa...@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" <jm...@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 <jm...@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 <an...@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...@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
>>> >>> ><sa...@gmail.com>wrote:
>>> >>> >
>>> >>> >> Please read the subject as "an empty region"
>>> >>> >>
>>> >>> >> From: samar kumar <sa...@gmail.com>
>>> >>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
>>> >>> >> To: "user@hbase.apache.org" <us...@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
>>> >>> >>
>>> >>> >>
>>> >>> >>
>>> >>>
>>> >>
>>> >>
>>>
>>>
>>>
>>
--
Harsh J
Re: an emtry region
Posted by J Mohamed Zahoor <jm...@gmail.com>.
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 <jm...@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 <sa...@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" <jm...@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 <jm...@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 <an...@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...@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
>> >>> ><sa...@gmail.com>wrote:
>> >>> >
>> >>> >> Please read the subject as "an empty region"
>> >>> >>
>> >>> >> From: samar kumar <sa...@gmail.com>
>> >>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
>> >>> >> To: "user@hbase.apache.org" <us...@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
>> >>> >>
>> >>> >>
>> >>> >>
>> >>>
>> >>
>> >>
>>
>>
>>
>
Re: NodeManager too many connections
Posted by Harsh J <ha...@cloudera.com>.
Hey Miguel,
Unsure why this needs to be on the HBase lists. I've moved it to
cdh-users@ since you're using that and it may be specific to that
version.
Can you send across a jstack of your NodeManager?
On Fri, Aug 10, 2012 at 3:17 PM, Miguel Costa <mi...@telecom.pt> wrote:
> Hi,
>
> NodeManager opens too much connections between the servers even if it isn't
> any yarn process running.
>
> This will kill Hdfs because of the open connections even if we change the
> number of possible opened connections.
>
> We already changed the netty jar to the final version but this continues to
> happen.
>
> We are using the latest beta Cloudera version.
>
> What can we do, so that this process doesn't happen?
>
> Thanks,
>
> Miguel
--
Harsh J
NodeManager too many connections
Posted by Miguel Costa <mi...@telecom.pt>.
Hi,
NodeManager opens too much connections between the servers even if it
isn't any yarn process running.
This will kill Hdfs because of the open connections even if we change
the number of possible opened connections.
We already changed the netty jar to the final version but this continues
to happen.
We are using the latest beta Cloudera version.
What can we do, so that this process doesn't happen?
Thanks,
Miguel
Re: an emtry region
Posted by J Mohamed Zahoor <jm...@gmail.com>.
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 <sa...@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" <jm...@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 <jm...@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 <an...@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...@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
> >>> ><sa...@gmail.com>wrote:
> >>> >
> >>> >> Please read the subject as "an empty region"
> >>> >>
> >>> >> From: samar kumar <sa...@gmail.com>
> >>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
> >>> >> To: "user@hbase.apache.org" <us...@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
> >>> >>
> >>> >>
> >>> >>
> >>>
> >>
> >>
>
>
>
Re: an emtry region
Posted by J Mohamed Zahoor <jm...@gmail.com>.
I will correct it..
I would love a link like that :-)
Thanks St.Ack
./Zahoor
On Mon, Aug 13, 2012 at 1:32 PM, Stack <st...@duboce.net> wrote:
> On Fri, Aug 10, 2012 at 8:37 AM, J Mohamed Zahoor <jm...@gmail.com>
> wrote:
> > Look at this post for more about Catalog Janitor
> >
> > http://blog.zahoor.in/2012/08/hbase-hmaster-architecture/
> >
>
> Nice blog Mohamed (Its 'HBase', not 'Hbase'). I added a link to it in
> our reference guide from the Master section (Hope you don't mind).
>
> St.Ack
>
Re: an emtry region
Posted by Stack <st...@duboce.net>.
On Fri, Aug 10, 2012 at 8:37 AM, J Mohamed Zahoor <jm...@gmail.com> wrote:
> Look at this post for more about Catalog Janitor
>
> http://blog.zahoor.in/2012/08/hbase-hmaster-architecture/
>
Nice blog Mohamed (Its 'HBase', not 'Hbase'). I added a link to it in
our reference guide from the Master section (Hope you don't mind).
St.Ack
Re: an emtry region
Posted by samar kumar <sa...@gmail.com>.
@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" <jm...@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 <jm...@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 <an...@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...@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
>>> ><sa...@gmail.com>wrote:
>>> >
>>> >> Please read the subject as "an empty region"
>>> >>
>>> >> From: samar kumar <sa...@gmail.com>
>>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
>>> >> To: "user@hbase.apache.org" <us...@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
>>> >>
>>> >>
>>> >>
>>>
>>
>>
Re: an emtry region
Posted by J Mohamed Zahoor <jm...@gmail.com>.
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 <jm...@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 <an...@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...@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
>> ><sa...@gmail.com>wrote:
>> >
>> >> Please read the subject as "an empty region"
>> >>
>> >> From: samar kumar <sa...@gmail.com>
>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
>> >> To: "user@hbase.apache.org" <us...@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
>> >>
>> >>
>> >>
>>
>
>
Re: an emtry region
Posted by J Mohamed Zahoor <jm...@gmail.com>.
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 <an...@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...@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
> ><sa...@gmail.com>wrote:
> >
> >> Please read the subject as "an empty region"
> >>
> >> From: samar kumar <sa...@gmail.com>
> >> Date: Tue, 07 Aug 2012 15:57:04 +0530
> >> To: "user@hbase.apache.org" <us...@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
> >>
> >>
> >>
>
RE: an emtry region
Posted by Anoop Sam John <an...@huawei.com>.
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...@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
><sa...@gmail.com>wrote:
>
>> Please read the subject as "an empty region"
>>
>> From: samar kumar <sa...@gmail.com>
>> Date: Tue, 07 Aug 2012 15:57:04 +0530
>> To: "user@hbase.apache.org" <us...@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
>>
>>
>>
Re: an emtry region
Posted by samar kumar <sa...@gmail.com>.
@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...@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
><sa...@gmail.com>wrote:
>
>> Please read the subject as "an empty region"
>>
>> From: samar kumar <sa...@gmail.com>
>> Date: Tue, 07 Aug 2012 15:57:04 +0530
>> To: "user@hbase.apache.org" <us...@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
>>
>>
>>
Re: an emtry region
Posted by syed kather <in...@gmail.com>.
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 <sa...@gmail.com>wrote:
> Please read the subject as "an empty region"
>
> From: samar kumar <sa...@gmail.com>
> Date: Tue, 07 Aug 2012 15:57:04 +0530
> To: "user@hbase.apache.org" <us...@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
>
>
>
Re: an emtry region
Posted by samar kumar <sa...@gmail.com>.
Please read the subject as "an empty region"
From: samar kumar <sa...@gmail.com>
Date: Tue, 07 Aug 2012 15:57:04 +0530
To: "user@hbase.apache.org" <us...@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