hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Konstantin Shvachko (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-4849) Idempotent create and append operations.
Date Wed, 19 Jun 2013 18:59:20 GMT

    [ https://issues.apache.org/jira/browse/HDFS-4849?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13688320#comment-13688320
] 

Konstantin Shvachko commented on HDFS-4849:
-------------------------------------------

That is right, Steve. You want something more from the operations than just being idempotent.
Your definition is equivalent to:
{color:green}_create(path, NS1) = create(path, NS2) for any NS1 and NS2_{color}
I don't think this is what traditionally called _idempotent_.
I am also not sure it is necessary to impose such requirement on file system operations.
Some references would be good to have.
                
> Idempotent create and append operations.
> ----------------------------------------
>
>                 Key: HDFS-4849
>                 URL: https://issues.apache.org/jira/browse/HDFS-4849
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: namenode
>    Affects Versions: 2.0.4-alpha
>            Reporter: Konstantin Shvachko
>            Assignee: Konstantin Shvachko
>            Priority: Blocker
>         Attachments: idempotentCreate.patch, idempotentCreate.patch, idempotentCreate.patch
>
>
> create, append and delete operations can be made idempotent. This will reduce chances
for a job or other app failures when NN fails over.

--
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

Mime
View raw message