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Bryan Duxbury commented on HADOOP-2443: --------------------------------------- You know what, I think you're right. I must have only tested it in scenarios when there are single tables. I've opened a new issue to track this problem, HADOOP-2631. I am resolving this issue again, because it's already been committed. > [hbase] Keep lazy cache of regions in client rather than an 'authoritative' > list > -------------------------------------------------------------------------------- > > Key: HADOOP-2443 > URL: https://issues.apache.org/jira/browse/HADOOP-2443 > Project: Hadoop > Issue Type: Improvement > Components: contrib/hbase > Reporter: stack > Assignee: Bryan Duxbury > Fix For: 0.16.0 > > Attachments: 2443-v10.patch, 2443-v3.patch, 2443-v4.patch, > 2443-v5.patch, 2443-v6.patch, 2443-v7.patch, 2443-v8.patch, 2443-v9.patch > > > Currently, when the client gets a NotServingRegionException -- usually > because its in middle of being split or there has been a regionserver crash > and region is being moved elsewhere -- the client does a complete refresh of > its cache of region locations for a table. > Chatting with Jim about a Paul Saab upload issue from Saturday night, when > tables are big comprised of regions that are splitting fast (because of bulk > upload), its unlikely a client will ever be able to obtain a stable list of > all region locations. Given that any update or scan requires that the list > of all regions be in place before it proceeds, this can get in the way of the > client succeeding when the cluster is under load. > Chatting, we figure that it better the client holds a lazy region cache: on > NSRE, figure out where that region has gone only and update the client-side > cache for that entry only rather than throw out all we know of a table every > time. > Hopefully this will fix the issue PS was experiencing where during intense > upload, he was unable to get/scan/hql the same table. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.