hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HDFS-3693) QJM: JNStorage should read its storage info even before a writer becomes active
Date Fri, 20 Jul 2012 00:52:34 GMT

     [ https://issues.apache.org/jira/browse/HDFS-3693?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Todd Lipcon updated HDFS-3693:
------------------------------

    Attachment: hdfs-3693.txt

Attached patch changes the StorageInfo to happen right when the journal is first accessed.

If the journal is unformatted, then it waits until a writer becomes active to format it (since
that writer is the one who provides the NamespaceInfo with which to format).

The patch includes an update to the unit test to verify the improved behavior. A future functional
test case which involves HA namenodes also depends on this, but this patch just has the targeted
test.
                
> QJM: JNStorage should read its storage info even before a writer becomes active
> -------------------------------------------------------------------------------
>
>                 Key: HDFS-3693
>                 URL: https://issues.apache.org/jira/browse/HDFS-3693
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>    Affects Versions: QuorumJournalManager (HDFS-3077)
>            Reporter: Todd Lipcon
>            Assignee: Todd Lipcon
>            Priority: Minor
>         Attachments: hdfs-3693.txt
>
>
> In order for QJM to work with HA, the standby needs to be able to read from a JournalNode
even when no active has written to it. In the current code, it reads the StorageInfo only
when {{newEpoch()}} is called. But, that's only called when a writer becomes active. This
causes the SBN to fail at startup since the JN thinks its storage info is uninitialized.

--
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

        

Mime
View raw message