[
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_20121215b.patch
h4103_20121215b.patch: changes also removeChild and replaceChild.
The patch is getting bigger. I will try to split it.
> 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,
> h4103_20121210b.patch, h4103_20121210.patch, h4103_20121211.patch,
> h4103_20121212b.patch, h4103_20121212.patch, h4103_20121213.patch,
> h4103_20121215b.patch, h4103_20121215.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
