[Gluster-users] Gluster and Cloudera's Hadoop

[Jay Vyas]

Hi james ! 

1) Yes, right now, we run as root.  Thanks for noticing :) ... We are working on modifying this in the very near future.   The problem is that 
the plugin attempts to mount a filesystem, but we recently have discussed that auto mount behaviour may be a superfluous feature, since mounting can easily be automated for
nodes in a cluster.

2) You're right the pervious version of the gluster hadoop filesystem implementation did not deal correctly with privileges.  
This is now fixed, however.  You can get a "bleeding edge" jar which fixes your permissions error from the 
glusterfs-hadoop github repository: https://github.com/gluster/hadoop-glusterfs, where these fixes have been merged into head. 

Also we can get you this jar prebuilt if you want, just let me know!

Thanks for trying out the GlusterFileSystem and keep the feedback coming !

----- Original Message -----
From: "James Gurtowski" <gurtowskij at gmail.com>
To: jvyas at redhat.com
Cc: gluster-users at gluster.org
Sent: Monday, April 8, 2013 2:17:44 PM
Subject: Gluster and Cloudera's Hadoop

Hello,

It seems the gluster hadoop plugin assumes all hadoop daemons/commands are
run as root? I was having trouble getting the jobtracker to start because
every time the fs is initialized a system call "mount -t glusterfs ..." is
issued. Cloudera runs all daemons as the mapred user who is not allowed to
run mount, so this is failing. I modified GlusterFileSystem.java (see
attached diff) and set fs.glusterfs.automount to false in core-site.xml so
this wouldn't happen.
That fixed the initial issue of getting daemons to start.

My next issue is getting hadoop jobs to run. I get an error:

File /mnt/glusterfs/user/james/.staging/job_201304081221_0013/job.xml does
not exist.

I believe this to be a permissions issue, I can access this file fine from
my account, but the .staging directory is only accessible by the user who
launches the job :

drwx------ 8 james james 870 Apr  8 14:10 .staging

If I change the permissions, they are changed back (by Cloudera's hadoop)
when I launch a job:
Permissions on staging directory
glusterfs://node001:9000/user/james/.staging are incorrect: rwxrwxrwx.
Fixing permissions to correct value rwx------

Any ideas of a work around would be greatly appreciated.

Thanks,
James