[Mailman-Developers] Responsiveness

[Barry A. Warsaw]

>>>>> "CVR" == Chuq Von Rospach <chuqui@plaidworks.com> writes:

    CVR> The obverse of that is that end-users seriously dislike
    CVR> delays, especially on conversational lists. It turns into the
    CVR> old "user expectation" problem -- it's better to hold ALL
    CVR> mail for 15 minutes so users come to expect it than to
    CVR> normally deliver mail in 2 minutes, except during the worst
    CVR> bulges...

That's been my experience as well.  People expect email to do strange
things to conversations, like show you replies before you've seen the
original message, or have turnaround times on the order of
quarter-hours or whatever.  It's when the behavior they expect changes
that people start to notice.

Case in point: I recently moved most of the python.org mailing lists
to a new, faster machine with better network connectivity.  Turnaround
time tanked and I started getting complaints that messages weren't
being seen in inboxes after 6 hours or so.  To make matters worse,
those messages were /in/ the archive!  <scratch> <scratch>.  Ah ha!
/etc/syslog.conf was configured to log mail.* and syslogd was starving
the MTA.
    
    CVR> But in general, the MLM should deliver as fast as
    CVR> it reasonable can without overloading the MUA, which implies
    CVR> some kind of monitoring setup for the MUA, or some
    CVR> user-controlled throttling system. the latter unfortunately,
    CVR> implies teaching admins how to monitor and adjust, a support
    CVR> issue. The former implies writing an interface for every MTA
    CVR> -- a development AND support issue.

Let me change that a little bit.  The MLM should /process/ messages as
fast as possible, getting them through the moderate-and-munge and into
the outbound queue at top speed possible.  Once that message is
sitting in that outbound queue, it's that queue's runner process that
can be configured to throttle, distribute, batch, whatever it takes.
It's not the MLM's problem (not to say it isn't the problem of the
simple-minded qrunner script we distribute and enable by default).
All I need to do is document the file format for the outbound queue
files and site administrators can take it from there.

-Barry