[Mailman-Users] Doing load balancing with mailman
Marc MERLIN
marc_news at valinux.com
Thu Nov 16 04:53:04 CET 2000
[I didn't Cc mailman-developers, but if I should ask programing specific
questions there, let me know]
While a correctly tuned mailman+exim config should be able to handle
sourceforge's lists just fine, I've been encouraged to look into a
failover/load balancing solution :-)
So, I've seen two options so far:
Option #1:
Lists are physically split between let's say 2 mail servers.
All mail goes to listname at lists.sourceforge.net, which is MXed the two mail
servers. I know how to configure exim so that it rewrites the envelope To to
resend the mail to the other list server if listname is not local to that
mail server.
So far so good.
The problem, is that for web access, I then have to show URLs with
http://lists1.sourceforge.net/lists/listinfo/listname
and
http://lists2.sourceforge.net/lists/listinfo/listname
Ok, that can be fixed with some clever apache rewriting/proxying, but it'd
be a bit iffy.
As far as failover is concerned, I can rsync the list configs on a periodic
basis and with some symlink magic, I could have one mail server mostly take
over the other mail server's lists if it were to disappear.
This requires mail header rewriting, http URL rewriting, plus other magic,
and it's not very "automatic".
Option #2:
Hold on, this is scary :-)
/var/local/mailman is NFS mounted on the mail servers.
/var/local/mailman/qfiles is a symlink to local disk
qrunner is modified to set a lockfile in qfiles and not data (it should
hopefully be a simple patch)
cron jobs are run on only one mail server, with the exception of qrunner.
both mail servers offer web access (same URL with load balancing) to the
same lists.
Voila :-)
Did I forget anything? Is there any reason why this wouldn't work?
(mailman's locking looks NFS safe to me, but I don't know if having locks
created for possibl the same lists in the mailman/locks directory, by two
different machines would be a problem for some reason that would escape me
right now).
Is there anything else besides qrunner that I'd need to patch?
Thanks
Marc
--
Microsoft is to operating systems & security ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/ | Finger marc_f at merlins.org for PGP key
More information about the Mailman-Users
mailing list