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Kihwal Lee commented on HDFS-11742: ----------------------------------- bq. do you think this is a blocker for 2.7.4 - it's marked as such? It caused performance regression for us. The impact depends on the scale and the nature of imbalance. We would not run the new balancer (now back-ported to 2.7.4) without this. > Improve balancer usability after HDFS-8818 > ------------------------------------------ > > Key: HDFS-11742 > URL: https://issues.apache.org/jira/browse/HDFS-11742 > Project: Hadoop HDFS > Issue Type: Bug > Reporter: Kihwal Lee > Assignee: Kihwal Lee > Priority: Blocker > Labels: release-blocker > Attachments: balancer2.8.png, balancer_fix.png, > HDFS-11742.branch-2.8.patch, HDFS-11742.branch-2.patch, > HDFS-11742.trunk.patch, HDFS-11742.v2.trunk.patch, replaceBlockNumOps-8w.jpg > > > We ran 2.8 balancer with HDFS-8818 on a 280-node and a 2,400-node cluster. In > both cases, it would hang forever after two iterations. The two iterations > were also moving things at a significantly lower rate. The hang itself is > fixed by HDFS-11377, but the design limitation remains, so the balancer > throughput ends up actually lower. > Instead of reverting HDFS-8188 as originally suggested, I am making a small > change to make it less error prone and more usable. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org