> This is fixed in CDH3 via HDFS-630: > https://issues.apache.org/jira/browse/HDFS-630
My bad that's HDFS-611: https://issues.apache.org/jira/browse/HDFS-611 Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White) --- On Mon, 1/24/11, Andrew Purtell <[email protected]> wrote: > From: Andrew Purtell <[email protected]> > Subject: Re: DFS rebalancing with running HBase > To: [email protected] > Date: Monday, January 24, 2011, 5:42 AM > Martin, > > The trouble was due to a defect in how HDFS managed > partitioning deletion work among the datanodes. Especially > when under high write load, HBase can post a lot of deletes > due to compactions. Running the balancer just makes it worse > -- additional replications into the face of uneven deletion > just brings the end faster when a datanode fills. > > This is fixed in CDH3 via HDFS-630: > https://issues.apache.org/jira/browse/HDFS-630 > > This is fixed in HDFS 0.21 + via HADOOP-5124: > https://issues.apache.org/jira/browse/HADOOP-5124 > > All, > > It might be a good idea to apply one of these fixes to the > ASF 0.20-append branch. > > Best regards, > > - Andy > > Problems worthy of attack prove their worth by hitting > back. > - Piet Hein (via Tom White) > > > --- On Mon, 1/24/11, Martin Fiala <[email protected]> > wrote: > > > From: Martin Fiala <[email protected]> > > Subject: DFS rebalancing with running HBase > > To: [email protected] > > Date: Monday, January 24, 2011, 4:21 AM > > Hello, > > > > in one old thread regarding hadoop/hbase 0.19.x > Andrew > > Purtell wrote, that running DFS balancer while HBase > is > > running, is not recommended. I didn't find any remarks > about > > this in Hadoop or HBase documentation. > > > > http://mail-archives.apache.org/mod_mbox/hbase-user/200905.mbox/%[email protected]%3e > > > > Is it still the case? What bad things can happen? > > > > It is quite clear, that with writing heavily to HBase > and > > running balancer simultaneously, the cluster is not > going to > > be balanced. It can become even more unbalanced. > > What about running balancer when we are only reading > from > > HBase or writing small amounts of records? > > > > Regards, > > Martin Fiala > > > > > >
