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-3229) add JournalProtocol RPCs to list finalized edit segments, and read edit segment file from JournalNode.
Date Mon, 09 Apr 2012 22:27:19 GMT

    [ https://issues.apache.org/jira/browse/HDFS-3229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13250251#comment-13250251

Todd Lipcon commented on HDFS-3229:

bq. However, if we believe we need web UI for JournalNode, we need the port anyways.

I think it's a good idea, since we have other endpoints in our default HTTP server that are
very useful for ops -- for example the /jmx servlet and the /conf servlet can both be very
handy. I also think exposing a basic web UI is helpful to operators who might try to understand
the current state of the system.

bq. Suppose we used HTTP server to synchronize the lagging JournalNode by downloading missed
edit logs from another Journal Node. Firstly, the lagging JN needs to get (e.g., by asking
for NN) a list of JNs with full set of edit logs. Then, it downloads the missed logs from
a good JN through http, while it could accept streamed logs from NN through rpc at the same
time. Given the two servers are working on different file sets(finalized logs vs in-progress
log), synchronizing them seems not a concern.

Right - this is the same process that the 2NN uses to synchronize finalized log segments from
the NN. See SecondaryNameNode.downloadCheckpointFiles for the code.
> add JournalProtocol RPCs to list finalized edit segments, and read edit segment file
from JournalNode. 
> -------------------------------------------------------------------------------------------------------
>                 Key: HDFS-3229
>                 URL: https://issues.apache.org/jira/browse/HDFS-3229
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: ha, name-node
>            Reporter: Brandon Li
>            Assignee: Brandon Li

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