ctdb relock file issues with glusterfs

[Michael Adam]

Hi folks,

as indicated elsewhere already, before even trying to start and
debug ctdb, you should make sure that your cluster setup provides
correct posix fcntl byte range locks, by using the ping_pong
tool shipped with the ctdb package:

https://wiki.samba.org/index.php/Ping_pong

It is important to verify that the locks really reach "the other
node", i.e. there is real lock contention.

This can in particular be tested with the -rw option to
ping_pong: If you run "ping_pong -rw /path/to/file 3" on
one node and then "ping_pong -rw /path/to/file 3" on a second
node, you should see the "data increment" notice (going from "1"
to "2"), indicating that you now have two processes operating
on the same file. If this stays constant (at 1) then your gluster
setup does not provide sufficient fcntl byte range lock support.

Another way to verify this without "-rw" is using file that is
one too small:  run "ping_pong /path/to/file 2" on one node and
then the same command on a second node. These should block and
not print positive lock rates. If instead both happily print positive
lock rates then your locks don't reach the other node and you
need to fix your setup...

Cheers - Michael

On 2012-10-09 at 22:21 +0000, Morten Bøhmer wrote:
> Can confirm that I am experiencing the exact same issue.
> 
> Would love to be able to solve this .....
> 
> 
> Morten
> ________________________________________
> From: samba-technical-bounces at lists.samba.org [samba-technical-bounces at lists.samba.org] on behalf of patrick medina [pgmedinajr at gmail.com]
> Sent: Wednesday, October 10, 2012 12:10 AM
> To: samba-technical at lists.samba.org
> Subject: Re: ctdb relock file issues with glusterfs
> 
> Afternoon/Morning Samba folks,
> 
> I finally made some progress this afternoon, let me explain what I found.
> 
> 1.  When I created the lock file, I had set it to chmod 777 (rwxrwxrwx)
> Thinking about permissions, I recreated the lock file with rw-r--r--.
>  After doing this I am now able to bring one node to healthy at a time, but
> the other node will stay unhealthy.  I am able to juggle healthy nodes by
> shutting the ctdb service down and the 2nd node will become healthy.
> 
> Log file on the unhealthy nodes complain about the recovery lock file not
> locked:
> 
> 2012/10/09 14:55:40.335328 [set_recmode:16493]: ctdb_recovery_lock: Got
> recovery lock on '/mnt/gluster/ctdb/lock'
> 2012/10/09 14:55:40.335448 [set_recmode:16493]: ERROR: recovery lock file
> /mnt/gluster/ctdb/lock not locked when recovering!
> 
> 
> 2.  I created new mount point on one of the nodes, so each node has a
> unique mount to gluster.  Depending on which node starts first, the
> unhealthy node complaints about the others recovery lock location.  How can
> this be if each node has it's on config file to go off of?
> 
> Node1:  CTDB_RECOVERY_LOCK="/mnt/fuse/ctdb/lock"
> ctdb_recovery_lock: Unable to open /mnt/gluster/ctdb/lock - (No such file
> or directory)
> 
> 
> Node2:  CTDB_RECOVERY_LOCK="/mnt/gluster/ctdb/lock"
> ctdb_recovery_lock: Unable to open /mnt/fuse/ctdb/lock - (No such file or
> directory)
> 
> Thanks again, I'm not sure where to troubleshoot next.
> 
> Regards,
> Gilbert
> 
> 
> 
> On Tue, Oct 9, 2012 at 5:20 AM, Martin Schwenke <martin at meltin.net> wrote:
> 
> > On Tue, 9 Oct 2012 16:32:12 +1100, Amitay Isaacs <amitay at gmail.com>
> > wrote:
> >
> > > On Tue, Oct 9, 2012 at 1:55 PM, patrick medina <pgmedinajr at gmail.com>
> > wrote:
> > > > Howdy samba folks,
> > > >
> > > > I've been running into a lot of issues lately with ctdb's re-lock file
> > and
> > > > glusterfs as the shared storage.  When I started, I could get one or
> > the
> > > > other node to become healthy, but at least one would complain it could
> > not
> > > > lock the re-lock file.  Nowi'm at the point where neither node will
> > become
> > > > healthy and stay in a recovery loop.  Just to be sure it was the
> > re-lock
> > > > file, I commented it out in the config and both nodes became healthy.
> >
> > > What version of CTDB are you using? Can you attach the log file where
> > > you notice CTDB is continuously going in recovery? It would be useful
> > > to get log files from all the nodes.
> >
> > Michael Adam and I took a look at this on the weekend.  Gilbert sent me
> > some logs and this was happening:
> >
> >   ctdb_recovery_lock: Got recovery lock on '/mnt/gluster/ctdb/lock'
> >
> > That seems to indicate that locking isn't working as expected...
> >
> > peace & happiness,
> > martin
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