[SURBL-Discuss] Re: [SURBL-Zones] Lowering TTLs

Jeff Chan jeffc at surbl.org
Sat Sep 11 03:44:42 CEST 2004


OK we tried one week of TTLs at 15 minutes (after a week at 25
then 20 minutes) and the DNS traffic levels don't seem much
higher because of it:

  http://nmrl.kconline.com/rbldnsd/

The measurement is perhaps slightly complicated by the fact
that people may be moving over to multi.surbl.org with
SpamAssassin 3.0, but looking at the relatively unchanging
lists, the shorter TTL change seems to have not had much effect
on traffic or only increased it slightly.  (Note how traffic
on multi is growing while the others (presumably using SA 2.63
and 2.64 or urirhsbl with SA 3.0) essentially aren't.)

We already know the traffic is significantly higher at 10 minute
TTLs, from the sc.surbl.org setting before (in the first week on
the sc graph), so 15 minutes is probably optimal in terms of
quickest additions and deletions from the list while also
minimizing DNS traffic.

So I'd like to propose that we stick with 15 minute TTLs
for all SURBLs.

Any comments?

Are we on the right track with this?

Jeff C.
-- 
Jeff Chan
mailto:jeffc at surbl.org
http://www.surbl.org/



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