Author: Marc Perkel Date: To: Brian Blood CC: Exim Mailing List Subject: Re: [exim] Fastest Exim server ever
Brian Blood wrote: > On Feb 29, 2008, at 1:52 PM, Ken Price wrote:
>
>
>>> The MTA has to be able to receive 50k/second in bursts and get
>>> them out
>>> as quick as possible. Probably not as fast as coming in but from
>>> what I
>>> understand delivery speed is important.
>>> It's coming from some sort of SQL server that they say can deliver it
>>> that fast.
>>>
>> Don't think one server. Think multiple, less powerful servers. 50k
>> unique messages a second isn't a realistic goal from a single server.
>> Theoretically, you're talking 50k outbound connections to remote MX
>> servers.
>>
>> Also, and I hate saying this, but the advanced features, flexibility,
>> and functionality that make Exim so great will also hinder you. You
>> don't need a full blown MTA here. Don't hate me, but I REALLY
>> recommend Qmail in this application. It's fast, lightweight, and for
>> this application ... simple. Might as well go with djbdns on the
>> local machines for DNS caching, too.
>>
>
>
> I do a lot of architectural consulting for scalable systems and my
> sense is the following:
>
> If they have some app that can lay down 50K emails in one second what
> needs to be happening is not SMTP, but something that directly drops
> those messages into an MTA's queue directory.
>
> And that MTA should NOT be Exim. Exim is the cat's meow for being
> able to PROGRAM your inbound email. A high-performance SMTP delivery
> system it is not. Mr Hazel has stated so himself.
>
> And for the reason that Marc mentioned (non-RFC compliant behavior in
> regards to MX records) and a few others, it should NOT be Qmail.
>
> The MTA I would recommend for high speed delivery of these messages
> is Postfix. A highly tuned Postfix configuration at that.
>
> As for your hardware, you want a server with LOTS of RAM, dual quad
> core, local caching name server, and a VERY fast disk subsystem.
>
> If the application really does call for SMTP for initial delivery out
> of the App, then the executable that sending these will be making TCP
> connections directly out of the app to an STMTP server. And, as Ken
> rightly suggests, this calls for multiple servers configured as above
> sitting behind a Load Balancer. You need to pipeline as much as
> possible out of that app, and that takes tuning.
>
> MY 2 cents.
>
>
> Brian
>
>
What makes you think that Postfix is faster than Exim? Have you tested it?