[Dovecot] Scalability plans: Abstract out filesystem and make it someone else's problem

[Eric Rostetter]

On Aug 12, 2009, at 2:21 AM, Steffen Kaiser <skdovecot at smail.inf.fh-brs.de 
 > wrote:

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> On Tue, 11 Aug 2009, Eric Jon Rostetter wrote:
>
>> For a massively scaled system, there may be sufficient performance to
>> put the queues elsewhere.
>
> Which also allows that the queue can easily have multiple machines  
> pushing & poping items.

Pushing is easy. Popping can be more problematic, depending on varios  
factors.

>> But on a small system, with 90% of the mail
>> being spam/virus/malware, performance will usually dictate local/ 
>> memory
>> file systems for such queues...
>
> Well, this discussion reads a bit like "local filesystems are prone  
> to loose data on crash".
> Journaling filesystems, RAID1 / 5 / 10, SANs do their job.

The issue I brought up is OS caching and is not dependent on the  
backend really. Only real solution is redundent storage AND disabling  
OS caching, which is not cheap and won't be the best performance.   
Always a tradeoff.


> However, I guess that Seth and Timo look at the thing from a  
> different point of view, Timo seems to focus on "one queue -  
> multiple accessees", whereas Seth focuses on temporary working  
> directory.

Well Timo looks at it from dovecot's point of view.

I look at it from a mail server's point of view (MTA also, etc).

> Bye,
>
> - -- Steffen Kaiser
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