Dovecot cluster using GlusterFS

[Michael Schwartzkopff]

Am Sonntag, 6. Dezember 2015, 20:33:32 schrieb list at airstreamcomm.net:
> We ran a load test using glusterfs and were able to deliver mail (I can't
> remember specifically how much per second, maybe 100 messages per second?)
> without any issues.  We did use the glusterfs fuse client and not nfs, and
> used regular maildir.  We developed a mail bot cluster that would deliver
> mail, and simultaneously receive and delete it with pop and IMAP and we ran
> into zero issues.  We even had the replicas stretched between two
> datacenters.  Not sure what the difference here is but it can be done.
> > On Dec 5, 2015, at 3:42 AM, Filip Pytloun <filip at pytloun.cz> wrote:
> > 
> > Hello,
> > 
> > I have recently setup mailserver solution using 2-node master-master
> > setup (mainly based on MySQL M-M replication and GlusterFS with 2
> > replica volume) on Ubuntu 14.04 (Dovecot 2.2.9).
> > 
> > Unfortunately even with shared-storage-aware setting:
> > 
> > mail_nfs_index = yes
> > mail_nfs_storage = yes
> > mail_fsync = always
> > mmap_disable = yes
> > 
> > ..I have hit strange issues pretty soon especially when user was
> > manipulating same mailbox from multiple devices at the same time.
> > 
> > Most issues was about corrupted indexes which was solved easily by just
> > putting them on local storage of each node:
> > 
> > mail_location = maildir:/srv/mail/%d/%u:INDEX=/var/lib/dovecot/index/%d/%u
> > 
> > But I still hit issues like this one:
> > 
> > dovecot: lmtp(6276, user at example.com): Error: Broken file
> > /srv/mail/example.com/user at example.com/dovecot-uidlist line 8529: UIDs
> > not ordered (8527 >= 8527)
> > 
> > Which I am not sure how serious it is or if it's possible to solve or
> > workaround?

hi,

I did experiments with glusterfs and dovecot about one year ago and ran into 
the same trouble. It was quite easy to corrupt users mailboxes delivering mail 
somultaniously on different nodes.

I tried a lot of different configurations (see NFS recomendations, ...) but 
nothig really solved the problem.

Also from the list I did not get any useful comments.

So I decided that plain dovecot / glusterfs is not usable.

I would be glad to hear of any other experiance and configuration tweaks.

Mit freundlichen Grüßen,

Michael Schwartzkopff

-- 
[*] sys4 AG

http://sys4.de, +49 (89) 30 90 46 64, +49 (162) 165 0044
Franziskanerstraße 15, 81669 München

Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263
Vorstand: Patrick Ben Koetter, Marc Schiffbauer
Aufsichtsratsvorsitzender: Florian Kirstein
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 230 bytes
Desc: This is a digitally signed message part.
URL: <http://dovecot.org/pipermail/dovecot/attachments/20151207/38c02702/attachment.sig>