accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Josh Elser (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-3957) Consider moving off getContentSummary in the monitor
Date Tue, 11 Aug 2015 21:16:46 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-3957?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14687403#comment-14687403
] 

Josh Elser commented on ACCUMULO-3957:
--------------------------------------

I tagged the 1.5/1.6/1.7 releases just in case this turn out to be a bad thing to do. I still
don't have a good reason as to why this caused so many problems. That will likely influence
my opinion on what change should actually be made.

> Consider moving off getContentSummary in the monitor
> ----------------------------------------------------
>
>                 Key: ACCUMULO-3957
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-3957
>             Project: Accumulo
>          Issue Type: Bug
>          Components: monitor
>            Reporter: Josh Elser
>            Assignee: Josh Elser
>            Priority: Critical
>             Fix For: 1.6.4, 1.7.1, 1.8.0, 1.5.4
>
>
> Recently heard about an issue where a large Hadoop installation which had Accumulo running
was experiencing long pauses in the Namenode. Inspecting NN audit logs, it was found that
the user running Accumulo issues a {{getContentSummary("/")}} call just before the NN pauses
were experienced.
> In {{DefaultServlet.java}}, we use this call to compute the total HDFS disk usage and
present a ratio of space that Accumulo uses relative to the total available space.
> It's still unclear why this was causing issues in this case (as this operation should
only be acquiring a read-lock in the namenode), it was recommended to me that Accumulo use
the JMX metrics for the NN instead of making this call.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message