At 4:37 PM +0200 2004-10-28, Fil wrote:
I don't understand this language, sorry. We have just upgraded the I/O capacity of the server, and it's working fine with every other piece of software, no problem with postfix handling tons of emails for example.
The same sorts of problems generally face Mailman as face other
programs, and the same sorts of solutions are usually useful for Mailman. So, solid-state disks, high-capacity RAID 1+0 arrays with high-speed controllers and large amounts of battery-backed write-back cache, etc....
If you're confused about a lot of these terms, I'd recommend
reading the book by Nick Christenson entitled _sendmail Performance Tuning_, which is linked from that first page I mentioned.
But still when we're talking about a 15-60 seconds lock for each subscriber, even if we could have the hardware go twice faster, it's way too slow.
I think it would be profitable to find out why VirginRunner is
holding the lock this long.
That's why I believe only the database backend can help (or any other software modification). What's especially wierd is that probe sending is very costly, but personalization or VERP-delivery is not that costly.
There are people who have done database back-end stuff for
Mailman 2.x, but so far as I know none of that has been integrated back into the mainstream code base. Those are all one-off operations. There will be a database back-end built into Mailman3, but it's still in the design phase right now.
If you can't find out why VirginRunner is holding the locks so
long, then the best thing to do would be turn off the VERP bounce probes.