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Re: productivity?

2011-08-23 04:30:17
On 2011-08-22 17:23:26 -0400, Hector Santos wrote:
Steve Atkins wrote:
Measuring actual costs (what is the resource cost of session setup
and teardown, and of maintaining an open session, for
well-implemented, mainstream MTAs?) would seem to be something to do
before discussing such a document in much detail.

Definitely. The assumption that the number of concurrent connection is
the only (or at least most important) limit doesn't seem realistic to

For those interested, if basic laws of operations research, physics,  
science and Thermodynamics isn't good enough, then Believe Sendmail!

    The ConnectionCacheTimeout ( K) option specifies the maximum time
    that any cached connection will be permitted to idle. When the idle
    time exceeds this value the connection is closed. *This number  
should be
    small (under ten minutes) to prevent you from grabbing too many  
    from other hosts. The default is five minutes.*

I'm not sure what you are arguing here. That five minutes is a
reasonable idle time for connection caching? That there are MTAs with
ridiculously long defaults? 

BTW, I've never observed a sendmail to keep open an idle connection for
that long. Maybe that limit doesn't apply to "normal" connections
(according to the document you cited it only applies to "IPC
connections"[1]) or maybe that limit is only reached under rare
circumstances. I just tested an out-of-the-box sendmail-8.13 (with
ConnectionCacheTimeout=5m) and it sends the QUIT immediately after the
250 response to DATA.


[1] I couldn't find out what that is - the old sendmail paper from the
1980's uses the term as a synonym for "socket connection", but I'm not
sure if that's current usage.

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|_|_) | Sysadmin WSR       | "Netz der kleinen Geister".
| |   | hjp(_at_)hjp(_dot_)at         | 
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