accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Josh Elser (JIRA)" <>
Subject [jira] [Commented] (ACCUMULO-3957) Consider moving off getContentSummary in the monitor
Date Tue, 11 Aug 2015 00:54:45 GMT


Josh Elser commented on ACCUMULO-3957:

I am very curious as to why other large Accumulo installations haven't already run into this

There's also the consideration that this metric has cause confusion in the past of what it
means, so a possible resolution is to just nuke the metrics on the monitor due to it being
more harmful than helpful (that would require more discussion).

> Consider moving off getContentSummary in the monitor
> ----------------------------------------------------
>                 Key: ACCUMULO-3957
>                 URL:
>             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 {{}}, 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

View raw message