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- From: Richard Bullington <firstname.lastname@example.org>
- Date: Sat, 23 Mar 1996 04:34:28 -0500 (EST)
The Obscure Organization's 28.8kbps link to the 'net is saturated, due to
members to fix this. Donating some spare machine cycles and bandwidth for
mail delivery can save the list.
Until I can resolve the bandwidth problems, I am moderating the list and
halting discussion until we find a solution. Sorry, but I can't get my
for-pay work done with the line this slammed.
Hello. Sorry to interrupt the party, but...
My name is Richard Bullington. I run The Obscure Organization, a small
non-profit community networking initiative. Among other things, we host
Unfortunately for Obscure, the list has been growing and growing with no
end in sight. The main server runs Linux 1.2.13 on an ISA-bus 486DX-33 with
32MB RAM, and 1.6 GB of SCSI disk space.
I have had dozens of sendmail processes chewing up my memory and
swap space, pushing 30MB of active memory into swap.
Obscure's connection to the Internet runs over a 28.8kbps modem. Look at
http://www.obscure.org/statistics/traffic/ for a graph of the network
traffic. Note that the midpoint is 28.8kbps, and it had been bursting well
above that for several hour periods. The statistics have been broken since
I upgraded to Slackware 3.0. Using statnet, I have manually measured my
PPP connection running at about 4KBps (32Kbps), bursting often to 8.75KBps
(70Kbps!!!). V.42bis compression really does work :)
I am starting to hit a wall, where the PPP link is bursting above
28.8Kbps for a good portion of the day. Yesterday, Obscure sent out over
30,000 mail messages, and queued another 10,000:
Syslog Input: (total) Output Statistics:
File Date Msgs Kbytes AvgSz Sent AvgDelay Dferd Que'd Other Local SMTP
Mar 21 765 1730 2316 36019 05:08:11 137 9873 138 1118 33916
Mar 20 908 1509 1702 21031 02:44:42 88 727 66 1042 19212
(This is from syslog-stat.pl, which I have modified heavily. If there is
interest, I will create a web page that reveals all the tools I used to
diagnose this mail nightmare...)
The delays are getting larger and larger. March 21st represents about
sustained transfer rate of about 5Kbps. This would be nothing over ISDN,
or a T1 line, but it digs deep into a 28.8Kbps connection.
There are several ways out of this mess:
* Obscure can get a faster connection (I need $350 per month more to
jump to full-time 128K ISDN. I don't expect anyone on this list to
contribute enough to make a difference here).
and, the one that I'd like to try,
providing mail exploders for the various top-level domains and regions.
To provide a mail exploder, all you need to do is have a relatively fast
and highly reliable machine (i.e. it is always running) with Sendmail V8
that can take some additional mail delivery load. A machine that already
acts as a mail hub for a medium sized organization is ideal. The machine
should have fast (128K+) connectivity to the 'Net and good links to
neighboring countries where appropriate (see domain breakdown at the end
of this message).
If you would like to volunteer for this, please let me know. You don't
need to do a thing to your systems, just give me the address of the
machine running sendmail, what domain or domains you want to act as a
hub for, and a brief description of the mail hub machine. You probably
won't even notice the load.
This rule, when landed in Ruleset 0 of the sendmail configuration, will
route mail for a particular top-level domain to a host running sendmail
for final delivery: (Thanks to Jeff Uphoff and the linux-security list)
R$*<@$+.domain.>$* $#esmtp $@router.host $:$1<@$2.domain.>$3
So, for all mail coming from Obscure to .com adddresses, the rule is:
R$*<@$+.com.>$* $#esmtp $@some.generous.soul.com $:$1<@$2.com.>$3
The vast majority (>90%) of the mail traffic from Obscure is for the
traffic from Obscure to the mail gateways for each domain.
Here is how many people are on the lists:
I wrote a small perl program that counts the top-level domains of
the email addresses. I have used the results to produce the following tables:
Here is a breakdown of top level domains by subscriber. I figure that we
need an exploders for at least 75% of these for the list to survive
Top Level Domains Aggregate Number of Subscribers
it de fr dk be at ch su 97
us ca org mil gov mx 64
jp kr hk sg tw my th 50
uk gb ie es pl 40
se no fi 40
au nz 24
This breakdown covers about 95% of all the addressees. Here is the full
breakdown by top level domain:
Top level domains:
Phew! If you made it all the way here, you have a lot of endurance. Sorry
for the long post, but I have been very frustrated, not being able to
effectively telecommute and get my real job done because of this.
Richard Bullington <email@example.com> http://www.obscure.org/