Delete the replica on the most concentrated node when raiding file ------------------------------------------------------------------
Key: MAPREDUCE-1831 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1831 Project: Hadoop Map/Reduce Issue Type: Improvement Components: contrib/raid Affects Versions: 0.22.0 Reporter: Scott Chen Assignee: Scott Chen Fix For: 0.22.0 In raid, it is good to have the blocks on the same stripe located on different machine. This way when one machine is down, it does not broke two blocks on the stripe. By doing this, we can decrease the block error probability in raid from O(p^3) to O(p^4) which can be a hugh improvement. One way to do this is that we can add a new BlockPlacementPolicy which delete the replicas that are co-located. So when raiding the file, we can make the remaining replicas live on different machines. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.