[Dovecot] dovecot-uidlist: Duplicate file entry at line

[Luca Palazzo]

Hi Timo and All,

On 09/03/2010 04:44 PM, Timo Sirainen wrote:
> On Thu, 2010-09-02 at 19:21 +0200, Luca Palazzo wrote:
>> Hi All,
>> we are experiencing another strange problem after upgrading to 2.0.1 
>> from 1.2.
>>
>> Many people's client aree-retrieving mail from server due to some 
>> problem with dovecot-uidlist file.
>> Looking at log file seem that all file content is sometime duplicated 
>> and appended to the and of same file.
>> It look as another process was accesing and trying to modify uidlist table.
> 
> I've heard of some dovecot-uidlist problems, but haven't really figured
> out anything that could be wrong.. I guess there's no way you can
> reproduce this? Does happen to same user more than once? How many users
> is "many"? Does this happen only/mainly to some specific mailboxes
> (INBOX, Trash)? Does this happen to more than one same user's mailbox at
> the same time? Does this happen to different users around the same time?
It's really difficult to understand how to reproduce it. We have about
6k maildirs and some of them, maybe about 200, are experiencing it more
often.
One this user has this problem accessing to mail by POP3 (so no other
folder other than INBOX) from three different client. I'll try to figure
if it's possible to have more info.
One interesting information is that log file complain that duplicated
UID line occur for all mails in uidlist file such as something is
duplicating all mails UID at the end of file
> 
>> Our setup has a load balance (dovecot director) and three backend 
>> server. All of them use 2.0.1.
> 
> How did you do it before v2.0?
Pre-2.0 we were using a IPVS load balancing so we had no user affinity
with server.
> 
> The maildir code hasn't changed much since v1.2. Hmm. Except that
> maildir filenames are now tried to be preserved when copying, so copying
> messages elsewhere and back does sound like it could cause this
> (although there is code to prevent it)..
> 
I think it's not related to mail copy due to POP3 usage of user that
experienced problem.

Luca