Re: [exim] 4096 connection barrier

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Author: Marc Perkel
Date:  
To: W B Hacker
CC: exim users
Subject: Re: [exim] 4096 connection barrier


W B Hacker wrote:
> Ian Eiloart wrote:
>
>> --On 23 February 2009 12:13:07 +0000 Graeme Fowler <graeme@???>
>> wrote:
>>
>>
>>> On Mon, 2009-02-23 at 11:45 +0000, Ian Eiloart wrote:
>>>
>>>> So, Exim's limit isn't reached on my machines, but nevertheless the
>>>> limit needs revisiting for those who don't have my problem. Marc's
>>>> right. The limit is too low for modern hardware.
>>>>
>>> ...to which the followup question is: what is a suitable limit for
>>> modern hardware and OS combinations?
>>>
>>> To expand a little on your OSX limits, should Exim be checking on OSX
>>> that it never spawns more than 2499 processes (queue runners, delivery
>>> processes, inbound handlers and so on)? Should it factor OS variations
>>> at all, or should they simply be documented?
>>>
>> It's not necessary to place a limit in OSX. I can do that with launchd
>> limits. What I set it to will depend on the other things that I'm using the
>> server for.
>>
>>
>>> What should be done to compare, say, Postfix / Sendmail et al?
>>>
>>> Most of these are (IMO) fairly rhetorical questions based on the fact
>>> that the following one-line change moves the goalposts:
>>>
>>> --- daemon.c.orig 2009-02-23 12:08:25.000000000 +0000
>>> +++ daemon.c 2009-02-23 12:08:40.000000000 +0000
>>> @@ -1199,3 +1199,3 @@
>>>
>>> - if (smtp_accept_max > 4095) smtp_accept_max = 4096;
>>> + if (smtp_accept_max > 16383) smtp_accept_max = 16384;
>>>
>>> But the first question stands: what value should be chosen? Or should
>>> there simply *not be* an upper limit, so people can skewer themselves if
>>> they choose an insane value for smtp_accept_max?
>>>
>> Well, I already can launch enough SMTP processes to hose my server,
>> unfortunately! I don't see why there should be a limit, but there should be
>> a sensible value in the default config file, and a note to caution that
>> Exim will launch up to smtp_accept_max processes.
>>
>>
>>> Graeme
>>>
>>
>>
>
> Obviously (posting from a PowerBook G4) I'm not an enemy of OS X.
>
> But might I ask why, on GGE, one would attempt to use that
> very-definitely-desktop-optimized OS for a *server* ???
>
> ... when several *BSD's and Linuxen run on the same hardware.. but NOT
> as the best of desktops there. OTOH, better desktps than 10.3.X if on
> Wintel/AMD/VIA.
>
> 'horses for courses' ?
>
> Regards,
>
> Bill
>
>


Agreed. In fact why buy super expensive Apple server hardware when you
can build a generic PC clone and run Linux on it? A quad core AMD with 8
gigs of ram and a 500G hard drive will cost you under $400.