[Mailman-Users] Config dump? - WAS Re: speed up mailman

[Hank van Cleef]

The esteemed Ruben Safir has said:
> 
> On 02/28/2016 03:57 PM, Tanstaafl wrote:
> > On 2/28/2016 1:19 PM, Stephen J. Turnbull <stephen at xemacs.org> wrote:
> >> If that doesn't make it obvious what you need to do, you might want to
> >> tell us something about your configuration and use case.  What version
> >> of Mailman?  Did you install as a package from a distribution or from
> >> source?  If from a distribution, which one?
> > 
> > Been meaning to ask...
> > 
> > Would it be difficult to add a command similar to postfix's postconf -n
> > that would dump the currently used config?
> > 
> When I read this, it just seems to me that you guys don't know how the 
> software works.  I posted logs to postfix and what they are asking is 
> frankly impossible to acquire.  This is a live system running a lot 
> of email in /var/spool/mail and the delays show up when the system 
> is under use.  I can't just restart it and expect the delays to 
> show up and I can't get answers to basic questions such as
> 
> When the email comes to mailman, where does it go.  How does the MTA know 
> to pick up the mail.  It seems to process mail in sweeps, rather than in 
> real time when mail arrives.
> 
<snip>

I'm going to chime in here, as a Mailman user, not as a list advisor.
Mark and Steve know perfectly well how the software works.  So do a good
many others who are reading this list.  I don't expect them to give you
a 3-semester-hour tutorial on E-mail basics.  They have asked you a few
fundamental questions, which I don't see being answered.  To wit:

a. What is your computer hardware?
b. What operating system are you running?
c. What is your current DNS setup?  (I presume a couple of ISP servers
not on your site).
d. Where did you get your Mailman package?  Prebuilt package for your
O/S?  Build and install from Mailman source?  
e. What are the contents of your mm_cfg.py file?  
f. What's the volume of your outgoing mail?  That's number of
messages/hr, average message size, number of users receiving mail.
And how much other mail is your MTA handling along with Mailman mail?
g. What is your connection to the internet backbone?  And what is your
upload speed?


>From looking at your Postfix logs, it looks as though you have a major
DNS problem.  I suggest that you install bind and set up a caching DNS
server on the same box that is running Mailman.  That will stop
dependence on external servers, which aren't set up to handle the floods
of requests that Mailman can generate.  Not only is that a matter of
common courtesy to outside sysadmins, any request flooding is going to
be handled much more quickly on your own box.  

I'm not familiar with Postfix and its logs, as I run Sendmail.  However,
I can tell you that reading the MTA logs carefully to see if initial
attempts to connect are failing, and asking "why," if they are, can go a
long way toward solving delay problems.  Remember that MTA's queue
connection failures for retry later, and those retries happen on 15
minute intervals in Sendmail default installations.  Mailman has logging
for its side of delivery to the MTA, as Mark has told you.  But I'll
suggest looking at MTA performance first.  Keep in mind that while
batching mail with a large RCPT list is efficient for some of the large
target sites, those sites often simply defer back with 4.xx responses
unless you cut down the number of RCPT's.  

If you haven't got a clear understanding of how SMTP E-mail works, there
are plenty of sources for study and learning.  One thing SMTP is not, is
"instantaneous," or even quick.  After all, it was developed for
slow-speed telephone lines a long time ago.  

Hank