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 <[email protected]> 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 > <[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 >> >>> >> >> >>> >> >> >>> >> >> >>> >> >> >> >> >> >> >> >
