[
https://issues.apache.org/jira/browse/HDFS-4140?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13493470#comment-13493470
]
Andy Isaacson commented on HDFS-4140:
-------------------------------------
bq. Do you have an idea for how to solve this problem in the "long term"?
We should error out when the user asks for semantics that we can't support
(overwriting part of a file without overwriting all of it). We should not
error out, and should provide correct semantics, when it is possible to do so.
Opening {{O_TRUNC}}
> fuse-dfs handles open(O_TRUNC) poorly
> -------------------------------------
>
> Key: HDFS-4140
> URL: https://issues.apache.org/jira/browse/HDFS-4140
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: fuse-dfs
> Affects Versions: 2.0.2-alpha
> Reporter: Andy Isaacson
> Assignee: Colin Patrick McCabe
> Attachments: HDFS-4140.003.patch
>
>
> fuse-dfs handles open(O_TRUNC) poorly.
> It is converted to multiple fuse operations. Those multiple fuse operations
> often fail (for example, calling fuse_truncate_impl() while a file is also
> open for write results in a "multiple writers!" exception.)
> One easy way to see the problem is to run the following sequence of shell
> commands:
> {noformat}
> ubuntu@ubu-cdh-0:~$ echo foo > /export/hdfs/tmp/a/t1.txt
> ubuntu@ubu-cdh-0:~$ ls -l /export/hdfs/tmp/a
> total 0
> -rw-r--r-- 1 ubuntu hadoop 4 Nov 1 15:21 t1.txt
> ubuntu@ubu-cdh-0:~$ hdfs dfs -ls /tmp/a
> Found 1 items
> -rw-r--r-- 3 ubuntu hadoop 4 2012-11-01 15:21 /tmp/a/t1.txt
> ubuntu@ubu-cdh-0:~$ echo bar > /export/hdfs/tmp/a/t1.txt
> ubuntu@ubu-cdh-0:~$ ls -l /export/hdfs/tmp/a
> total 0
> -rw-r--r-- 1 ubuntu hadoop 0 Nov 1 15:22 t1.txt
> ubuntu@ubu-cdh-0:~$ hdfs dfs -ls /tmp/a
> Found 1 items
> -rw-r--r-- 3 ubuntu hadoop 0 2012-11-01 15:22 /tmp/a/t1.txt
> {noformat}
--
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
