hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hairong Kuang (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-1435) Provide an option to store fsimage compressed
Date Fri, 01 Oct 2010 16:31:36 GMT

    [ https://issues.apache.org/jira/browse/HDFS-1435?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12916938#action_12916938
] 

Hairong Kuang commented on HDFS-1435:
-------------------------------------

Phillip, your suggestion definitely has value that gives the flexibility of compressing fsimage
at any time. The focus of this jira is to store it compressed by HDFS. This allows secondary
NN to transfer the compressed image to primary NN, thus reducing network & disk I/O overhead.

Jeff, I'd like to take a look at the Avro file format. Do you know if Avro file format has
any overhead than the current fsimage format?

> Provide an option to store fsimage compressed
> ---------------------------------------------
>
>                 Key: HDFS-1435
>                 URL: https://issues.apache.org/jira/browse/HDFS-1435
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: name-node
>    Affects Versions: 0.22.0
>            Reporter: Hairong Kuang
>            Assignee: Hairong Kuang
>             Fix For: 0.22.0
>
>
> Our HDFS has fsimage as big as 20G bytes. It consumes a lot of network bandwidth when
secondary NN uploads a new fsimage to primary NN.
> If we could store fsimage compressed, the problem could be greatly alleviated.
> I plan to provide a new configuration hdfs.image.compressed with a default value of false.
If it is set to be true, fsimage is stored as compressed.
> The fsimage will have a new layout with a new field "compressed" in its header, indicating
if the namespace is stored compressed or not.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message