+1 mahadev
On 1/21/10 2:46 PM, "Ryan Rawson" <ryano...@gmail.com> wrote: > Scaling _down_ is a continual problem for us, and this is one of the > prime factors. It puts a bad taste in the mouth of new people who then > run away from HBase and HDFS since it is "unreliable and unstable". It > is perfectly within scope to support a cluster of about 5-6 machines > which can have an aggregate capacity of 24TB (which is a fair amount), > and people expect to start small, prove the concept/technology then > move up. > > I am also +1 > > On Thu, Jan 21, 2010 at 2:36 PM, Stack <st...@duboce.net> wrote: >> I'd like to propose a new vote on having hdfs-630 committed to 0.21. >> The first vote on this topic, initiated 12/14/2009, was sunk by Tsz Wo >> (Nicholas), Sze suggested improvements. Those suggestions have since >> been folded into a new version of the hdfs-630 patch. Its this new >> version of the patch -- 0001-Fix-HDFS-630-0.21-svn-2.patch -- that I'd >> like us to vote on. For background on why we -- the hbase community >> -- think hdfs-630 important, see the notes below from the original >> call-to-vote. >> >> I'm obviously +1. >> >> Thanks for you consideration, >> St.Ack >> >> P.S. Regards TRUNK, after chatting with Nicholas, TRUNK was cleaned of >> the previous versions of hdfs-630 and we'll likely apply >> 0001-Fix-HDFS-630-trunk-svn-4.patch, a version of >> 0001-Fix-HDFS-630-0.21-svn-2.patch that works for TRUNK that includes >> the Nicholas suggestions. >> >> >> On Mon, Dec 14, 2009 at 9:56 PM, stack <st...@duboce.net> wrote: >>> I'd like to propose a vote on having hdfs-630 committed to 0.21 (Its already >>> been committed to TRUNK). >>> >>> hdfs-630 adds having the dfsclient pass the namenode the name of datanodes >>> its determined dead because it got a failed connection when it tried to >>> contact it, etc. This is useful in the interval between datanode dying and >>> namenode timing out its lease. Without this fix, the namenode can often >>> give out the dead datanode as a host for a block. If the cluster is small, >>> less than 5 or 6 nodes, then its very likely namenode will give out the dead >>> datanode as a block host. >>> >>> Small clusters are common in hbase, especially when folks are starting out >>> or evaluating hbase. They'll start with three or four nodes carrying both >>> datanodes+hbase regionservers. They'll experiment killing one of the slaves >>> -- datanodes and regionserver -- and watch what happens. What follows is a >>> struggling dfsclient trying to create replicas where one of the datanodes >>> passed us by the namenode is dead. DFSClient will fail and then go back to >>> the namenode again, etc. (See >>> https://issues.apache.org/jira/browse/HBASE-1876 for more detailed >>> blow-by-blow). HBase operation will be held up during this time and >>> eventually a regionserver will shut itself down to protect itself against >>> dataloss if we can't successfully write HDFS. >>> >>> Thanks all, >>> St.Ack >>
