Are you sure ? So why is the balancer disabled before rolling restart ?
On Mon, Dec 24, 2012 at 2:04 AM, <[email protected]> wrote: > They would move over to live region servers. > > Cheers > > > > On Dec 23, 2012, at 2:59 PM, Brennon Church <[email protected]> wrote: > > > I'm curious. If I disable the hbase balancer, what happens when a > regionserver goes offline? Will those regions get moved over to the > remaining hosts as would normally be the case? Or will they remain > unavailable until the balancer is run manually? > > > > Thanks. > > > > --Brennon > > > > On 12/22/12 5:48 AM, Ted Yu wrote: > >> When region splits, the daughter regions would be placed on the same > server > >> as parent region. > >> You also need to consider the case where new server crashes and its > regions > >> are moved to older system. > >> > >> In HBASE-5231 <https://issues.apache.org/jira/browse/HBASE-5231> you > can > >> find a patch which does per table load balancing. You can modify that > code > >> to move regions of selected table to pre-defined group of servers > >> (specified through configuration). > >> > >> Cheers > >> > >> On Fri, Dec 21, 2012 at 11:01 PM, Brennon Church <[email protected]> > wrote: > >> > >>> I do allow regions from other tables on the newer servers. The issue > >>> stems from a single table that habitually causes hot regions. Not such > a > >>> problem on the new servers, but when those regions hit the older > systems > >>> bad things happen. I think the proper long-term solution is to change > the > >>> code writing to the table, but that's not something that can be done > right > >>> now, so I'm looking for the second best option. > >>> > >>> The HBASE-6721 option sounds perfect, if I'm reading it correctly. It > >>> doesn't quite fit my use case, but would solve the problem regardless. > >>> > >>> If I understand the balancer part correctly, a possible but ugly (IMHO) > >>> option would be to move the region(s) causing trouble over to the more > >>> powerful servers then disable automatic balancing. Would region splits > >>> then remain on the same system as the original region? If so, it would > >>> work around the problem but at the expense of having to manually move > >>> regions around more frequently to keep everything else balanced. > >>> > >>> Thanks. > >>> > >>> --Brennon > >>> > >>> > >>> On 12/21/12 8:48 PM, Ted Yu wrote: > >>> > >>>> Brennon: > >>>> I forgot to ask you about other tables you have. Do you allow regions > of > >>>> other tables to also be assigned to this group of newer servers ? > >>>> If you do, there is possibility that the combined load on such new > servers > >>>> would make response from them slow. > >>>> > >>>> Cheers > >>>> > >>>> On Fri, Dec 21, 2012 at 8:28 PM, Ted Yu <[email protected]> wrote: > >>>> > >>>> What you describe is akin to HBASE-6721 region server group. > >>>>> Basically you want this table to be bound to group of region servers. > >>>>> > >>>>> Development for 0.94 is on-going, to my knowledge. > >>>>> > >>>>> Cheers > >>>>> > >>>>> > >>>>> On Fri, Dec 21, 2012 at 7:30 PM, Brennon Church <[email protected] > >>>>>> wrote: > >>>>> 0.92.0 > >>>>>> I was looking at the balancer option. I'm loathe to turn the > automatic > >>>>>> balancer off and handle it manually as we have a lot of regions. Is > >>>>>> that > >>>>>> the option you were thinking of? Or am I missing something? > >>>>>> > >>>>>> Thanks. > >>>>>> > >>>>>> --Brennon > >>>>>> > >>>>>> > >>>>>> On 12/21/12 4:19 PM, Ted Yu wrote: > >>>>>> > >>>>>> Currently there is no such capability - you may need to customize > load > >>>>>>> balancer. > >>>>>>> > >>>>>>> What version of HBase are you using ? > >>>>>>> > >>>>>>> Cheers > >>>>>>> > >>>>>>> On Fri, Dec 21, 2012 at 3:54 PM, Brennon Church < > [email protected]> > >>>>>>> wrote: > >>>>>>> > >>>>>>> I'm curious, is there any concept of hosting regions from a given > >>>>>>> table > >>>>>>> > >>>>>>>> only on a single host or subset of hosts in a cluster? In our > case we > >>>>>>>> have > >>>>>>>> a heavily-used table that can cause problems for the older > systems in > >>>>>>>> our > >>>>>>>> cluster. Newer systems would have less trouble, so I'd like to > >>>>>>>> restrict > >>>>>>>> regions for that one table only to those more powerful servers. > >>>>>>>> > >>>>>>>> Thanks. > >>>>>>>> > >>>>>>>> --Brennon > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>> > > > > > -- Adrien Mogenet 06.59.16.64.22 http://www.mogenet.me
