Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hdfs-issues@hadoop.apache.org
Date: Sat, 10 Nov 2012 23:33:12 +0000 (UTC)
From: "Suresh Srinivas (JIRA)" <jira@apache.org>
To: hdfs-issues@hadoop.apache.org
Message-ID: <100339739.97181.1352590392275.JavaMail.jiratomcat@arcas>
In-Reply-To: <15764769.148771292458021796.JavaMail.jira@thor>
Subject: [jira] [Commented] (HDFS-1539) prevent data loss when a cluster
 suffers a power loss
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HDFS-1539?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13494800#comment-13494800 ] 

Suresh Srinivas commented on HDFS-1539:
---------------------------------------

Nicholas, compared the backported patch with the original. It looks good. +1 for the patch.

We should get this into 1.1.1.
                
> prevent data loss when a cluster suffers a power loss
> -----------------------------------------------------
>
>                 Key: HDFS-1539
>                 URL: https://issues.apache.org/jira/browse/HDFS-1539
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: data-node, hdfs client, name-node
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>             Fix For: 0.23.0
>
>         Attachments: syncOnClose1.txt, syncOnClose2_b-1.txt, syncOnClose2.txt
>
>
> we have seen an instance where a external outage caused many datanodes to reboot at around the same time.  This resulted in many corrupted blocks. These were recently written blocks; the current implementation of HDFS Datanodes do not sync the data of a block file when the block is closed.
> 1. Have a cluster-wide config setting that causes the datanode to sync a block file when a block is finalized.
> 2. Introduce a new parameter to the FileSystem.create() to trigger the new behaviour, i.e. cause the datanode to sync a block-file when it is finalized.
> 3. Implement the FSDataOutputStream.hsync() to cause all data written to the specified file to be written to stable storage.

--
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