hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Raghu Angadi (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-15) All replicas of a block end up on only 1 rack
Date Thu, 20 Aug 2009 21:02:14 GMT

    [ https://issues.apache.org/jira/browse/HDFS-15?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12745640#action_12745640
] 

Raghu Angadi commented on HDFS-15:
----------------------------------

I am in favor of  not having another list. I looked at the patch briefly, not sure if having
extra set reduces new code.. Are you implying newer proposal has less changes? 

It is better to have 'neededReplicationList' to have all the block that need replication.
May be 'UnderReplicatedBlocks' could be renamed. 

> All replicas of a block end up on only 1 rack
> ---------------------------------------------
>
>                 Key: HDFS-15
>                 URL: https://issues.apache.org/jira/browse/HDFS-15
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Hairong Kuang
>            Assignee: Jitendra Nath Pandey
>            Priority: Critical
>         Attachments: HDFS-15.patch
>
>
> HDFS replicas placement strategy guarantees that the replicas of a block exist on at
least two racks when its replication factor is greater than one. But fsck still reports that
the replicas of some blocks  end up on one rack.
> The cause of the problem is that decommission and corruption handling only check the
block's replication factor but not the rack requirement. When an over-replicated block loses
a replica due to decomission, corruption, or heartbeat lost, namenode does not take any action
to guarantee that remaining replicas are on different racks.
>  

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message