[
https://issues.apache.org/jira/browse/HADOOP-3799?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12707779#action_12707779
]
dhruba borthakur commented on HADOOP-3799:
------------------------------------------
@Hairong: fsck uses verifyReplication() to ensure whether replicaas are placed
according to the configured policy, and this method is part of the proposed
BlockPlacement policy interface. Balancer does not use the configured policy
but ensures that the number of unique racks for the block is not reduced. Thus,
both these components should work ok with a externally configured replication
policy, isn't it?
> Design a pluggable interface to place replicas of blocks in HDFS
> ----------------------------------------------------------------
>
> Key: HADOOP-3799
> URL: https://issues.apache.org/jira/browse/HADOOP-3799
> Project: Hadoop Core
> Issue Type: Improvement
> Components: dfs
> Reporter: dhruba borthakur
> Assignee: dhruba borthakur
> Attachments: BlockPlacementPluggable.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.
