hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jiayi Zhou (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-10519) Add a configuration option to enable in-progress edit log tailing
Date Tue, 14 Jun 2016 17:49:28 GMT

    [ https://issues.apache.org/jira/browse/HDFS-10519?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15330013#comment-15330013

Jiayi Zhou commented on HDFS-10519:

Maybe I got something wrong, but isn't the MetaRecoveryContext already null at the beginning?

In doTailEdits() from EditLogTailer, we have 
                              streams = editLog.selectInputStreams(lastTxnId + 1, 0, null,

Here, MetaRecoverContext is null. And in image.LoadEdits(), we have
                              public long loadEdits(Iterable<EditLogInputStream> editStreams,
                                      FSNamesystem target) throws IOException {
                                return loadEdits(editStreams, target, null, null);
MetaRecoveryContext is also null.

Also, I don't know why toAtLeastTxId is always set to 0 in the implementation, making the
checkForGaps() method no use. If we set it to some other value, like lastTxnId + 1, the multiple
replay should be rejected.

> Add a configuration option to enable in-progress edit log tailing
> -----------------------------------------------------------------
>                 Key: HDFS-10519
>                 URL: https://issues.apache.org/jira/browse/HDFS-10519
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: ha
>            Reporter: Jiayi Zhou
>            Assignee: Jiayi Zhou
>            Priority: Minor
>         Attachments: HDFS-10519.001.patch, HDFS-10519.002.patch
> Standby Namenode has the option to do in-progress edit log tailing to improve the data
freshness. In-progress tailing is already implemented, but it's not enabled as default configuration.
And there's no related configuration key to turn it on.
> Adding a related configuration key to let Standby Namenode is reasonable and would be
a basis for further improvement on Standby Namenode.

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org

View raw message