Subject: bug#40775: 28.0.50; dns-query sometimes infloops

From: Lars Ingebrigtsen <[email-masked]>
Date: Thu, 28 Jan 2021 07:55:57 +0100

Tassilo Horn <[email-masked]> writes:

>> Since the recent changes to gravatar.el, the standard gravatar service
>> is libravatar now.

(This bit was changed because of privacy concerns.)

> Ok, I think I have it.  It doesn't infloop, it just takes a lot of time
> for DNS queries on some domains, and if the From, To and Cc of a message
> contain many mail addresses, and for each one there are two dns-queries,
> then it may add up to long delays (of several minutes).
>
> For example, for me with emacs -Q
>
>   (benchmark-run 1
>     (dns-query "_avatars-sec._tcp.zjp.codes" 'SRV)
>     (dns-query "_avatars._tcp.zjp.codes" 'SRV))
>
> consistently takes 20 seconds, 10 seconds for each (unsuccessful) query.
> Those queries will be performed for every [email-masked] mail address in
> a message.

These lookups should now be cached, so the delay should only happen the
first time, which should help some.  And all the lookups should be
asynchronous, I think, so there should be no hangs.  (If I remember
correctly.)

So I think everything in this bug report should work better now?  Are
you still seeing problems in this area (if you're still using
libravatar)?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no