[Mailman-Developers] big list

Nick Simicich njs+mailman@scifi.squawk.com
Sat, 09 Mar 2002 19:21:43 -0500


At 02:52 AM 2002-03-09 -0500, Ron Jarrell wrote:
>At 01:46 PM 3/8/02 -0800, John W Baxter wrote:
> >Aside:  how far we've come from the old mainframe LISTSERV, the network of
> >which carefully sent one copy along with a list to addresses to various
> >neighbors "near" the addressees for further distribution.  So quite likely,
> >only one copy crossed the Atlantic...possibly one one went from Chicago to
> >Florida, etc etc.
>
>Still does, to some extent.  Listserv passes jobs to other listservs when it
>can figure out that's useful.  Also, part of the license fee for running 
>listserv
>is access to be able to distribute big jobs to lsofts large server, and 
>let them
>deal with delivering it for you.

Actually, the recent releases say things in their control file like "This 
server has been down since 1999 and it does not look like it will ever be 
brought up again."

And Listserv has gone "open source".  I have decided to migrate away from 
my hand tuned Majordomo 1, and I have been investigating various mailing 
list programs. (Mailman is one of them -- and I am still unsure what 
version I should install --- since this is a new attempt at installation, 
should I install the beta, or should I stick with the stable version? -- I 
really want custom footers...)  I got a copy of the open source listserv, 
and I have compiled it, but so far as I can tell, the distribution is 
missing essential text files that do not come except with a licensed 
prepared binary copy - it is about to get deleted from my system, even 
though it seems to have a bunch of nice features, and I have a kind of 
nostalgic desire to run it.

The folding of network topology knowledge into the mail distribution 
manager made sense when networks were simpler - and when they typically 
were store and forward.  Remember that the network this was made for was an 
"NJE" or "RSCS" store and forward network - the unit of transmission was 
not the packet, it was an e-mail (actually, file, an e-mail was just a file 
with a special name)...the e-mail was not sent directly to a destination, 
in fact, there was no way to get to the destination "directly" unless it 
was local.  The e-mail was sent to a node that was closer to the 
destination.  And that node figured out a route and sent it on forward.  It 
*could* take days for a message to cross the Atlantic if the links were 
saturated.  And it was not unheard for a bunch of messages to be spun off 
to tape, and for that tape to be Fedexed or DHL'd to a node much closer to 
the destination, so as to get around an overloaded link. (We used a bitnet 
like network in IBM --- and sometimes there was only a small pathway 
between countries, with files that could take a day in transit tying it 
up.  Early versions of the protocol could send one thing at a time across a 
link, and short files were preferred, but once a long file started, it 
monopolized the link until it finished.  Later versions could subdivide a 
link and multiplex.)

The point was that the machines like Listserv, or the thing called Toolsrun 
that we used inside of IBM, could "understand" the network topology and 
could shed subscriptions to closer servers.  As well as holding archives 
closer to the end user....

But these days, frankly, teaching your mailing list server about network 
topology seems counter-productive.  The knowledge of network topology 
belongs, if anywhere, in the MTA and the database that describes that, in 
our case, the DNS.

For example, the concept of "Florida" is more or less meaningless.  My 
system is in Florida, the one that I am typing this note on.  The packets 
that leave this system go to a router that, I am told, has a "Florida" name 
when I reverse translate it, but which is actually in Chicago 
somewhere.  They actually traverse the link on something that is probably 
ATM, with virtual circuits set up so that it is actually a small piece of a 
bigger pipe -- but the next time that this is surfaced into a router that 
looks at the IP layer is across the country.

So for me to look for an IRC server that is in Chicago is sort of 
silly.  Those packets at least go across the country once, and then they 
might come back to Florida - even if they come back on XO's net, they cross 
the country twice.

Putting this sort of "layer violation" in Listserv was probably essential 
at the time.  A link of 4800 BPS or slower was not uncommon at the time 
that the Bitnet protocols were designed.  1200 was the limit for dial-ups, 
and a lot of mail was moved by store and forwards such as bitnet, or even 
uucpnet.   For a long time, RSCS nodes would not burst - that is, you could 
not drop a piece of mail into the RSCS or NJE networks with multiple 
destinations and have it manage the shipment of copies to end nodes.  Every 
destination had to have its own copy traversing those slow links.

But had that existed from day one, the listserv and toolsrun shedding of 
subscriptions to "closer" nodes might never have existed.

 From my listserv control file:

 ># NOTE: as of May 1999 the global server is down, and it may never be
 ># re-established.  So for now the following two items should remain
 ># commented out.  - Harold
 >
 ># Define the global query server for all lists worldwide.  If you
 ># don't want your server to forward requests for unknown lists,
 ># comment out this line.  Otherwise, you should leave it as-is.
 >#
 >#global-query-server listproc@listproc.listproc.net listproc.listproc.net 372
 >
 ># Define the master server for collecting global list information, and
 ># the time to send a list of published lists daily.  Comment this out
 ># if you don't want your server to notify the global server about your
 ># published lists.  Otherwise, this should be left as-is.
 >#
 >#global-update-server global-update-server@listproc.listproc.net 04:00


--
War is an ugly thing, but it is not the ugliest of things. The decayed and 
degraded state of moral and patriotic feeling which thinks that nothing is 
worth war is much worse. A man who has nothing for which he is willing to 
fight, nothing he cares about more than his own personal safety, is a 
miserable creature who has no chance of being free, unless made so by the 
exertions of better men than himself. -- John Stuart Mill
Nick Simicich - njs@scifi.squawk.com