hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tsz Wo (Nicholas), SZE (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HDFS-4103) Support O(1) snapshot creation
Date Mon, 10 Dec 2012 04:01:20 GMT

     [ https://issues.apache.org/jira/browse/HDFS-4103?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Tsz Wo (Nicholas), SZE updated HDFS-4103:
-----------------------------------------

    Attachment: h4103_20121209b.patch

h4103_20121209b.patch: updated with the branch.
                
> Support O(1) snapshot creation
> ------------------------------
>
>                 Key: HDFS-4103
>                 URL: https://issues.apache.org/jira/browse/HDFS-4103
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: namenode
>    Affects Versions: Snapshot (HDFS-2802)
>            Reporter: Tsz Wo (Nicholas), SZE
>            Assignee: Tsz Wo (Nicholas), SZE
>         Attachments: h4103_20121129.patch, h4103_20121202b.patch, h4103_20121202.patch,
h4103_20121209b.patch, h4103_20121209.patch
>
>
> In our first snapshot implementation, snapshot creation runs in O(N) and occupies O(N)
memory space, where N = # files + # directories + # symlinks in the snapshot.  The advantages
of the implementation are that there is no additional cost for the modifications after snapshots
are created, and it leads to a simple implementation.
> In this JIRA, we optimize snapshot creation to O(1) although it introduces additional
cost in the modifications after snapshots are created.  Note that the INode is given as an
assumption, otherwise, there is a non-constant cost to find the INode.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message