[Mailman-Developers] VERPing: ouch!

[Brad Knowles]

At 11:14 PM +0200 2004-07-12, Fil wrote:

>  I think there's a small design flaw with the once-in-a-wile VERPing scheme.
>  My biggest list is 180k subscribers, and I've set up Mailman to VERP once
>  every 10th message. Well, it happened today that the big list was hit by its
>  VERP time, and it's a bit awful - it looks like the list has taken control
>  of Mailman, and no other mail can pass through it.

	Well, a 180k list is pretty big by Mailman standards.  That's the 
largest list in current operations that I know of.  There have been 
larger lists in the past, but I haven't heard of any this size or 
larger since.

	A big list is going to be painful to send out, if you don't have 
the hardware sized and configured correctly for this.  Search the FAQ 
wizard for the word "performance" and read every entry returned, if 
you want to get some idea of what this entails.

>  I think it might be wiser to say "every 10th recipient" is VERPed at each
>  sending, than what we have now. Of course, it needs rotating things, or
>  randomizing them, so it's not a two-lines of code I guess.

	As you point out, this is a non-trivial change.

>  Meanwhile I'll just have to disable VERP for this list (or for the whole
>  server).

	I imagine that disabling VERP for this one list should probably 
be enough.  If it wasn't, you would have been coming to us already 
asking about how you can tune your performance.

-- 
Brad Knowles, <brad.knowles at skynet.be>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.