hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Suresh Srinivas (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-4258) Rename of Being Written Files
Date Fri, 15 Mar 2013 21:24:14 GMT

    [ https://issues.apache.org/jira/browse/HDFS-4258?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13603869#comment-13603869
] 

Suresh Srinivas commented on HDFS-4258:
---------------------------------------

bq. I think supporting file descriptor behavior is a great idea (we've internally talked about
this). Until we do, I think the lease should be revoked. My concerns with fd behavior would
be the ever pervasive "two wrongs make a right" where users are relying unintentionally on
renames breaking writers, and ensuring we get the security right to avoid attacks probing
for fileids.

Aaron and Daryn, there is no security issue related to being able to guess fileids. It is
nothing different from being able to guess valid paths in HDFS.

I posted a proposal to HDFS-4489. Please take a look.
                
> Rename of Being Written Files
> -----------------------------
>
>                 Key: HDFS-4258
>                 URL: https://issues.apache.org/jira/browse/HDFS-4258
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: hdfs-client, namenode
>    Affects Versions: 3.0.0
>            Reporter: Tsz Wo (Nicholas), SZE
>            Assignee: Brandon Li
>         Attachments: HDFS-4258.patch, HDFS-4258.patch, HDFS-4258.patch, HDFS-4258.patch
>
>
> When a being written file or it's ancestor directories is renamed, the path in the file
lease is also renamed.  Then the writer of the file usually will fail since the file path
in the writer is not updated.
> Moreover, I think there is a bug as follow:
> # Client writes 0's to F_0="/foo/file" and writes 1's to F_1="/bar/file" at the same
time.
> # Rename /bar to /baz
> # Rename /foo to /bar
> Then, writing to F_0 will fail since /foo/file does not exist anymore but writing to
F_1 may succeed since /bar/file exits as a different file.  In such case, the content of /bar/file
could be partly 0's and partly 1's.

--
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