hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Colin Patrick McCabe (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-3608) fuse_dfs: detect changes in UID ticket cache
Date Tue, 10 Jul 2012 00:52:34 GMT

    [ https://issues.apache.org/jira/browse/HDFS-3608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13409988#comment-13409988
] 

Colin Patrick McCabe commented on HDFS-3608:
--------------------------------------------

I guess another way to do this would be to have a timer go off every minute or so causing
the ticket cache files to be marked as "must stat next time."  Of course the timer should
only be armed when there is actually something in the cache in the first place.  That would
actually be a reasonable way to do it.  As a bonus, we could finally dispose of the memory
in FileSystem objects after a while (something we do not currently do-- even after being used
once, they'll exist forever right now.)
                
> fuse_dfs: detect changes in UID ticket cache
> --------------------------------------------
>
>                 Key: HDFS-3608
>                 URL: https://issues.apache.org/jira/browse/HDFS-3608
>             Project: Hadoop HDFS
>          Issue Type: Bug
>    Affects Versions: 2.0.1-alpha
>            Reporter: Colin Patrick McCabe
>            Assignee: Colin Patrick McCabe
>            Priority: Minor
>
> Currently in fuse_dfs, if one kinits as some principal "foo" and then does some operation
on fuse_dfs, then kdestroy and kinit as some principal "bar", subsequent operations done via
fuse_dfs will still use cached credentials for "foo". The reason for this is that fuse_dfs
caches Filesystem instances using the UID of the user running the command as the key into
the cache.  This is a very uncommon scenario, since it's pretty uncommon for a single user
to want to use credentials for several different principals on the same box.
> However, we can use inotify to detect changes in the Kerberos ticket cache file and force
the next operation to create a new FileSystem instance in that case.  This will also require
a reference counting mechanism in fuse_dfs so that we can free the FileSystem classes when
they refer to previous Kerberos ticket caches.
> Another mechanism is to run a stat periodically on the ticket cache file.  This is a
good fallback mechanism if inotify does not work on the file (for example, because it's on
an NFS mount.)

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message