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Robert Chansler commented on HDFS-385: -------------------------------------- Is it possible this change led to the difficulty reported in HDFS-623? > Design a pluggable interface to place replicas of blocks in HDFS > ---------------------------------------------------------------- > > Key: HDFS-385 > URL: https://issues.apache.org/jira/browse/HDFS-385 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Fix For: 0.21.0 > > Attachments: BlockPlacementPluggable.txt, > BlockPlacementPluggable2.txt, BlockPlacementPluggable3.txt, > BlockPlacementPluggable4.txt, BlockPlacementPluggable4.txt, > BlockPlacementPluggable5.txt, BlockPlacementPluggable6.txt, > BlockPlacementPluggable7.txt > > > The current HDFS code typically places one replica on local rack, the second > replica on remote random rack and the third replica on a random node of that > remote rack. This algorithm is baked in the NameNode's code. It would be nice > to make the block placement algorithm a pluggable interface. This will allow > experimentation of different placement algorithms based on workloads, > availability guarantees and failure models. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.