Even with rep=1, HDFS appears like one single filesystem to HBase so the blocks that are remote to the region server will be fetched via network.
J-D On Fri, Oct 8, 2010 at 3:25 PM, yuliya Feldman <[email protected]> wrote: > Thanks for the link. It is very helpful. > > My concerns was that after HBase restart (table "dissapears" means - looks > like > some data got corrupted and HBase stopped showing my table in the list of > Tables) some regions that were originally created on one region server got > reassigned to different regionserver after restart, although physically data > still on data node of first region server. > > My replication was 1, so data belongs to just a single data node. > > Thanks > > > > ----- Original Message ---- > From: Jean-Daniel Cryans <[email protected]> > To: [email protected] > Sent: Fri, October 8, 2010 2:49:18 PM > Subject: Re: Question regarding regions move/assignement > > Not sure about the part where your table "disappears", but your > question is mostly answered in this blog post by our good friend Lars > G. http://www.larsgeorge.com/2010/05/hbase-file-locality-in-hdfs.html > > J-D > > On Thu, Oct 7, 2010 at 6:41 PM, yuliya Feldman <[email protected]> wrote: >> Hello here, >> >> I have a question regarding HBase data locality in respect to HDFS data >> nodes. >> As far as I understand regions created by region servers will happen to be >> physically created on local Data Node if RegionServer happen to run on one. >> >> I had an issue with writing to Meta table and my table "dissapeared" from >> list >> of tables. After I restarted hbase everything went back to normal, but >> regions >> got reassigned to different region servers they were originally created. >> >> How this "(re)assignment" mechanism actually works? >> >> I am using hbase 0.20.4 at the moment. >> >> Thanks >> >> >> >> >> > > > > >
