hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-3120) Provide ability to enable sync without append
Date Thu, 29 Mar 2012 23:07:26 GMT

    [ https://issues.apache.org/jira/browse/HDFS-3120?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13241908#comment-13241908

Todd Lipcon commented on HDFS-3120:

sounds good to me, +1 for that proposal
> Provide ability to enable sync without append
> ---------------------------------------------
>                 Key: HDFS-3120
>                 URL: https://issues.apache.org/jira/browse/HDFS-3120
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 1.0.1
>            Reporter: Eli Collins
>            Assignee: Eli Collins
> The work on branch-20-append was to support *sync*, for durable HBase WALs, not *append*.
The branch-20-append implementation is known to be buggy. There's been confusion about this,
we often answer queries on the list [like this|http://search-hadoop.com/m/wfed01VOIJ5]. Unfortunately,
the way to enable correct sync on branch-1 for HBase is to set dfs.support.append to true
in your config, which has the side effect of enabling append (which we don't want to do).
> Let's add a new *dfs.support.sync* option that enables working sync (which is basically
the current dfs.support.append flag modulo one place where it's not referring to sync). For
compatibility, if dfs.support.append is set, dfs.support.sync will be set as well. This way
someone can enable sync for HBase and still keep the current behavior that if dfs.support.append
is not set then an append operation will result in an IOE indicating append is not supported.
We should do this on trunk as well, as there's no reason to conflate hsync and append with
a single config even if append works.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira


View raw message