[Dovecot] Locking /var/mail/user issue with postfix and dovecot

[Stan Hoeppner]

On 10/25/2012 12:38 PM, Robert JR wrote:
> On 2012-10-25 21:23, Stan Hoeppner wrote:
> 
>> On 10/25/2012 1:00 PM, Stan Hoeppner wrote:
>>
>>> Switch Postfix to use the Dovecot Local Deliver Agent (LDA) in place of
>>> the Postfix local/virtual delivery agent. Using Dovecot LDA eliminates
>>> the file locking issue. Thus it also increases throughput as lock
>>> latency is eliminated. It also enables using all the Dovecot delivery
>>> plugins such as Sieve, Quota, anti-spam, etc.
>>
>> I forgot to mention one very important feature of Dovecot LDA:
>>
>> New messages delivered by Postfix are indexed by LDA as they are written
>> to the mailbox, flags updated at this time, etc. Thus when a mailbox is
>> opened in an IMAP MUA, new messages are displayed instantly (I don't use
>> POP but it's probably faster as well). With your current setup it can
>> take from a few to many seconds to show new mail, depending on message
>> count. With LDA new message count seems to have no impact on the speed
>> of display.
> 
> Thanks stan very much for your detailed answer, i will read about LDA to
> know how it works. But i still wonder why this mailbox locking issue and I
> hope for my referece some one at this form explain to me the issue reason.
> as since postfix,dovecot has the same lockign settings so why this issue
> happen ? I have spend 3 days searching for an answer and i couldnot find
> any.. I think only Timo can answer my question...

I chose to focus on the permanent and proper solution, which is
eliminating your lock contention altogether and enabling maximum
performance and features.

Learning about file locking problems between applications may be a noble
endeavor, but at this point it's simply a waste of your time.  A
gazillion papers have been written about this subject over the years.
If you're that interested hunt them down and read them.  I'm sure Google
can find 1000 of them quickly.  You'll be looking for academic papers,
not forum posts.

> Thanks again stan

You're welcome.

-- 
Stan