hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hadoop QA (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-7597) DNs should not open new NN connections when webhdfs clients seek
Date Fri, 08 May 2015 17:48:05 GMT

    [ https://issues.apache.org/jira/browse/HDFS-7597?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14535079#comment-14535079
] 

Hadoop QA commented on HDFS-7597:
---------------------------------

\\
\\
| (x) *{color:red}-1 overall{color}* |
\\
\\
|| Vote || Subsystem || Runtime || Comment ||
| {color:red}-1{color} | patch |   0m  0s | The patch command could not apply the patch during
dryrun. |
\\
\\
|| Subsystem || Report/Notes ||
| Patch URL | http://issues.apache.org/jira/secure/attachment/12692601/HDFS-7597.patch |
| Optional Tests | javadoc javac unit findbugs checkstyle |
| git revision | trunk / 3cefc02 |
| Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/10876/console |


This message was automatically generated.

> DNs should not open new NN connections when webhdfs clients seek
> ----------------------------------------------------------------
>
>                 Key: HDFS-7597
>                 URL: https://issues.apache.org/jira/browse/HDFS-7597
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: webhdfs
>    Affects Versions: 2.0.0-alpha
>            Reporter: Daryn Sharp
>            Assignee: Daryn Sharp
>            Priority: Critical
>              Labels: BB2015-05-TBR
>         Attachments: HDFS-7597.patch, HDFS-7597.patch
>
>
> Webhdfs seeks involve closing the current connection, and reissuing a new open request
with the new offset.  The RPC layer caches connections so the DN keeps a lingering connection
open to the NN.  Connection caching is in part based on UGI.  Although the client used the
same token for the new offset request, the UGI is different which forces the DN to open another
unnecessary connection to the NN.
> A job that performs many seeks will easily crash the NN due to fd exhaustion.



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

Mime
View raw message