While gathering statistics I found that these two variables displayed by pdns_control show are not equal as expected.
If i compare udp4-queries with udp4-answers and udp6-queries and udp6-answers, these do match.
As explained by habbie in IRC:
14:42:19 < abraxxl> how does the metric udp_answers and udp_queries correlate on an autoritative server? I have here a test setup that has 4times more answers than queries, but if send out a simple dig query to the server both metrics are only increased by one.
14:42:31 < Habbie> this sounds familiar
14:42:34 < Habbie> i'll look it up
14:44:25 < Habbie> udp_queries is increased apart from udp_answers in case of:
14:44:34 < Habbie> - broken query packet
14:44:51 < Habbie> - question on thread other than 0
14:45:09 < Habbie> abraxxl, can you check udp4/6-queries/answers and see if they make more sense?
14:53:08 < abraxxl> okay udp4-queries matches the udp-answers
14:53:26 < Habbie> ok
14:53:42 < abraxxl> but why is upd-queries 4 times lower, from your explanation I would say it should be higher
14:53:59 < Habbie> questions on a threat that is not thread 0
14:54:02 < Habbie> do not get counted for udp-queries
14:54:06 < Habbie> but do get counted for udp4/udp6-queries
14:54:35 < Habbie> what's your receiver-threads setting?
14:54:36 < Habbie> 4? :)
14:55:32 < abraxxl> ah, I understand, that clarifies things
14:55:35 < Habbie> a ticket about this issue might be in order, by the way
import a patch from Kees Monshouwer, closing #491 and #582
git-svn-id: svn://svn.powerdns.com/pdns/trunk/pdns@2999 d19b8d6e-7fed-0310-83ef-9ca221ded41b
fixed in r2999