hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Chen Liang (JIRA)" <j...@apache.org>
Subject [jira] [Comment Edited] (HDFS-11907) NameNodeResourceChecker should avoid calling df.getAvailable too frequently
Date Wed, 31 May 2017 19:14:05 GMT

    [ https://issues.apache.org/jira/browse/HDFS-11907?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16031765#comment-16031765
] 

Chen Liang edited comment on HDFS-11907 at 5/31/17 7:13 PM:
------------------------------------------------------------

Post v001 patch to only call {{availableSpace = df.getAvailable()}} to update the value at
most every 5 seconds.


was (Author: vagarychen):
Post v001 patch to only update call {{availableSpace = df.getAvailable()}} at most every 5
seconds.

> NameNodeResourceChecker should avoid calling df.getAvailable too frequently
> ---------------------------------------------------------------------------
>
>                 Key: HDFS-11907
>                 URL: https://issues.apache.org/jira/browse/HDFS-11907
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>            Reporter: Chen Liang
>            Assignee: Chen Liang
>         Attachments: HDFS-11907.001.patch
>
>
> Currently, {{HealthMonitor#doHealthChecks}} invokes {{NameNode#monitorHealth}} which
ends up invoking {{NameNodeResourceChecker#isResourceAvailable}}, at the frequency of once
per second by default. And NameNodeResourceChecker#isResourceAvailable invokes {{df.getAvailable();}}
every time it is called.
> Since available space information should rarely be changing dramatically at the pace
of per second. A cached value should be sufficient. i.e. only try to get the updated value
when the cached value is too old. otherwise simply return the cached value. This way df.getAvailable()
gets invoked less.
> Thanks [~arpitagarwal] for the offline discussion.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

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


Mime
View raw message