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

[Robert JR]

On 2012-10-25 23:18, Stan Hoeppner wrote:

> 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.

Thanks  again Stan, you are very helpfull, i will start learning how to 
configure LDA, but hopefully i can also have an answer from Timo about 
why this issue happened.. i am sure he is aware of it and can explain 
it..