[
https://issues.apache.org/jira/browse/HDFS-3941?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13498353#comment-13498353
]
Tsz Wo (Nicholas), SZE commented on HDFS-3941:
----------------------------------------------
> ... Can you take a look at it? ...
Sure, I have commented on HADOOP-9045.
We usually use a JIRA for a single issue/bug. The patch can be
merged/backported to earlier branches within the same JIRA. In this case,
let's keep HDFS-3941 for backporting HDFS-3498 and HDFS-3601, and then fix the
bug by HADOOP-9045 (so we will commit HADOOP-9045 to both trunk and branch-1).
Sounds good?
BTW, if you are busy on something, Jing can help out here.
> Backport HDFS-3498 and HDFS3601: update replica placement policy for new
> added "NodeGroup" layer topology
> ---------------------------------------------------------------------------------------------------------
>
> Key: HDFS-3941
> URL: https://issues.apache.org/jira/browse/HDFS-3941
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: name-node
> Affects Versions: 1.0.0
> Reporter: Junping Du
> Assignee: Junping Du
> Attachments: HDFS-3941.patch
>
>
> With enabling additional layer of "NodeGroup", the replica placement policy
> used in BlockPlacementPolicyWithNodeGroup is updated to following rules:
> 0. No more than one replica is placed within a NodeGroup (*)
> 1. First replica on the local node.
> 2. Second and third replicas are within the same rack but remote rack with
> 1st replica.
> 3. Other replicas on random nodes with restriction that no more than two
> replicas are placed in the same rack, if there is enough racks.
> Also, this patch abstract Replica Removal Policy from FSNameSystem to
> BlockPlacementPolicy and update removal policy slightly to remove duplicated
> replica within the same NodeGroup first when over-replicated happens.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
