Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hdfs-issues@hadoop.apache.org
Message-ID: <24624365.66491293667191946.JavaMail.jira@thor>
Date: Wed, 29 Dec 2010 18:59:51 -0500 (EST)
From: "Eli Collins (JIRA)" <jira@apache.org>
To: hdfs-issues@hadoop.apache.org
Subject: [jira] Updated: (HDFS-15) Rack replication policy can be violated
 for over replicated blocks
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


     [ https://issues.apache.org/jira/browse/HDFS-15?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Eli Collins updated HDFS-15:
----------------------------

    Summary: Rack replication policy can be violated for over replicated blocks   (was: All replicas of a block end up on only 1 rack)

> Rack replication policy can be violated for over replicated blocks 
> -------------------------------------------------------------------
>
>                 Key: HDFS-15
>                 URL: https://issues.apache.org/jira/browse/HDFS-15
>             Project: Hadoop HDFS
>          Issue Type: Bug
>    Affects Versions: 0.20.3
>            Reporter: Hairong Kuang
>            Assignee: Jitendra Nath Pandey
>            Priority: Critical
>             Fix For: 0.20.3, 0.21.0
>
>         Attachments: hdfs-15-b20-1.patch, HDFS-15.4.patch, HDFS-15.5.patch, HDFS-15.6.patch, HDFS-15.patch, HDFS-15.patch.2, HDFS-15.patch.3
>
>
> 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.