ah yes, there is some logic that prevents meta/root from being on the same RS, which is desirable in a larger configuration.
On Thu, Oct 15, 2009 at 11:16 AM, Yannis Pavlidis <[email protected]> wrote: > Hey Ryan, > > I performed additional testing with some alternate configurations and the > problem arises (ONLY) when there is only one regionserver left which has the > META table already assigned to it. > > In this case the ROOT table does not get assigned to the last regionserver > (which holds the META table). > > Interestingly enough though when there is only one regionserver left that has > the ROOT table already assign to it then it can also have the META table > re-assigned to it (if again is the only server - i.e. in this scenario you > can have one regionserver holding both the META and ROOT tables). > > Unless I am missing something I cannot find any reason why we cannot assign > the ROOT table to the regionserver that manages the META table if it is the > only one remaining (again it is an extreme case I agree that this can happen). > > I applied and tested a fix (at the hbase-0.20.0 codebase) in the > RegionManager::regionsAwaitingAssignment where I add the root table in the > regionstoAssign set if the it is the metaServer and also the only server. > > Here is the diff: > > diff RegionManager.java.FIXES RegionManager.java > 414c414 > < if ((!isMetaServer) || (isMetaServer && isSingleServer)) { > --- >> if (!isMetaServer) { > > Let me know what you guys think. > > Thanks, > > Yannis. > > -----Original Message----- > From: Ryan Rawson [mailto:[email protected]] > Sent: Wed 10/14/2009 5:58 PM > To: [email protected] > Subject: Re: ROOT table does not get re-assigned > > Hey, > > Next time, you can use a service like pastebin.com or anything else like that. > > So the log looks ok until the end. At that point, the master is > relying on a regionserver heartbeat back to the master so that the > master has a chance to direct the regionserver. But looks like the 3rd > and last regionserver doesnt check in? > > You say this is highly reproducible? Are you able to run your test on > more machines? A 3 node cluster is a little light, i wouldnt consider > running HBase and HDFS on < 10 nodes for production. It could be an > artifact of having only 3 nodes too... > > -ryan > >
