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Arpit Agarwal commented on HDFS-3702: ------------------------------------- [~eddyxu], given the size of the patch could you please summarize your approach. Perhaps a one page design note would be a good idea. Please hold off on committing this then. > Add an option for NOT writing the blocks locally if there is a datanode on > the same box as the client > ----------------------------------------------------------------------------------------------------- > > Key: HDFS-3702 > URL: https://issues.apache.org/jira/browse/HDFS-3702 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client > Affects Versions: 2.5.1 > Reporter: Nicolas Liochon > Assignee: Lei (Eddy) Xu > Priority: Minor > Labels: BB2015-05-TBR > Attachments: HDFS-3702.000.patch, HDFS-3702.001.patch, > HDFS-3702.002.patch, HDFS-3702.003.patch, HDFS-3702.004.patch, > HDFS-3702.005.patch, HDFS-3702.006.patch, HDFS-3702.007.patch > > > This is useful for Write-Ahead-Logs: these files are writen for recovery > only, and are not read when there are no failures. > Taking HBase as an example, these files will be read only if the process that > wrote them (the 'HBase regionserver') dies. This will likely come from a > hardware failure, hence the corresponding datanode will be dead as well. So > we're writing 3 replicas, but in reality only 2 of them are really useful. -- This message was sent by Atlassian JIRA (v6.3.4#6332)