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 <[email protected]>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" <[email protected]> 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 <[email protected]> > >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 <[email protected]> > >>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 [[email protected]] > >>> Sent: Tuesday, August 07, 2012 4:32 PM > >>> To: [email protected] > >>> 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" <[email protected]> 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 > >>> ><[email protected]>wrote: > >>> > > >>> >> Please read the subject as "an empty region" > >>> >> > >>> >> From: samar kumar <[email protected]> > >>> >> Date: Tue, 07 Aug 2012 15:57:04 +0530 > >>> >> To: "[email protected]" <[email protected]> > >>> >> 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 > >>> >> > >>> >> > >>> >> > >>> > >> > >> > > >
