[Dovecot] IMAP "freezing" on OSX

[Scott Murman]

are you using the dovecot lda, or postfix, or procmail?  i've been  
using dovecot on a PPC mac os x box for quite some time, but had to  
abandon the dovecot lda because of exactly the problems you  
describe.  i switched to postfix, then procmail, and have not had any  
problems since.

-SM-

On May 6, 2007, at 5:49 AM, Ben Carter wrote:

>
> Hi,
>
>  I've got a problem with dovecot on an Intel Mac OSX box.  
> Basically, I was running an older verion (0.8.?, I think), and  
> everything was fine. Then, when I upgraded to 1.0.0 via MacPorts, I  
> found that periodically the system gets into a state where it  
> simply stops dealing with IMAP requests.
>
>  This tends to manifest itself as Thunderbird simply stalling, not  
> fetching any new messages or folder contents. Sometimes quitting  
> and restarting Thunderbird will help, but at other times the  
> problem persists even afterwards. It seems to be linked to specific  
> mailboxes (or messages?) - often one "problem folder" will  
> reproduce the effect 100% whilst operating on the rest of the  
> mailbox is fine.
>
>  The problem /seems/ to often start as a result of trying to move  
> messages between folders. I'm not certain if that's a root cause,  
> though, or simply a consequence of "opening" an affected folder to  
> perform the move. I have a spam folder with a large number (>10000)  
> of messages in it, and trying to file stuff in there is a  
> relatively surefire way to generate the problem.
>
>  Once it's happened once, it inevitably escalates - restarting the  
> client helps a bit, as does restarting dovecot. However, the only  
> way to "fix" it and restore full functionality seems to be to  
> delete all of the index and dovecot* files from the mailbox and  
> folders... it generally takes a day or so after that before things  
> start to go wrong again.
>
>  All of this seems to point to corruption of the index files in  
> some way, but the log is universally unhelpful - there are no error  
> messages of any kind showing up there. The actual dovecot instance  
> doesn't appear to crash or even "hang" properly - you can still  
> make inbound IMAP connections OK, it's just that they don't ever  
> give a response to commands that touch the affected mailboxes.
>
>  Sometimes, I end up with temporary files lying around in the  
> folders in the mailbox - apparently mails which were in the process  
> of being moved when the server "gave up". I'm not sure if this is  
> actually part of the problem, though, or just a symptom.
>
> My configuration (from dovecot -n) is:
>
> # /opt/local/etc/dovecot/dovecot.conf
> ssl_disable: yes
> disable_plaintext_auth: no
> login_dir: /opt/local/var/run/dovecot/login
> login_executable: /opt/local/libexec/dovecot/imap-login
> mail_location: maildir:~/Library/Mail/IMAP
> auth default:
>   passdb:
>     driver: pam
>     args: *
>   userdb:
>     driver: passwd
>
> I'm running this on my personal machine, so there's only one user  
> on the system, which I have set up using MailDir (on HFS). There's  
> a fair bit of mail in many of my folders, but I doubt that's the  
> problem as the previous version didn't seem to have any issues...
>
> I'm doing mail delivery using postfix directly into the maildir  
> folders. That doesn't seem to be affected at all by this, though -  
> mail still arrives fine even when Dovecot is failing to serve the  
> folder contents to IMAP clients... you just can't see it ^-^
>
> Has anyone seen an effect like this? Or does anyone have any  
> pointers as to what I could try to debug it?
>
> Any suggestions would be very greatly appreciated!
>
>  Thanks!
> -- 
>  Ben Carter - ben at gunk.demon.co.uk / ben at saillune.net (preferred)
>