[ https://issues.apache.org/jira/browse/HBASE-21006?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16568474#comment-16568474 ]
Hari Sekhon edited comment on HBASE-21006 at 8/3/18 4:57 PM: ------------------------------------------------------------- Data locality % improves very, very slowly over the course of days after rolling restarts, eg. a few percent a day until it comes back up to around 90%. I suspect this is due to minor compactions re-writing blocks locally and not due to region migrations, which would mean that the balancer isn't optimising data locality back up. was (Author: harisekhon): Data locality % improves very, very slowly over the course of days after rolling restarts. I suspect this is due to minor compactions re-writing blocks locally and not due to region migrations, which would mean that the balancer isn't optimising data locality back up. > Balancer - data locality drops hugely after rolling restarts on cluster, not > factoring in data locality enough? > --------------------------------------------------------------------------------------------------------------- > > Key: HBASE-21006 > URL: https://issues.apache.org/jira/browse/HBASE-21006 > Project: HBase > Issue Type: Improvement > Components: Balancer > Affects Versions: 1.1.2 > Environment: HDP 2.6 > Reporter: Hari Sekhon > Priority: Major > > After doing rolling restarts of my HBase cluster the data locality drops by > 30-40% every time which implies the stochastic balancer is not optimizing for > data locality enough, at least not under the circumstance of rolling restarts. > The stochastic balancer is supposed to take data locality in to account but > if this is the case, surely it should move regions back to their original > RegionServer and data locality should return back to around where it was, not > drop by 30-40% percent every time I need to do some tuning and a rolling > restarts. -- This message was sent by Atlassian JIRA (v7.6.3#76005)