30 Bře
2017
30 Bře
'17
15:31
Hello!
On 03/30/2017 12:58 AM, Daniel Kahn Gillmor wrote:
I'm running kresd 1.2.4. If i start it with an
empty/missing cache, and
then receive a query for an A record for "www.ietf.org", there is a
substantial delay in the response.
[...]
In particular, the delay appears to be related to resolving AAAA records
for'ns1.yyz1.afilias-nst.info, but i don't know why. i do note that the
first time it shows up it's answered with "=> using root hints", but
then subsequent times don't seem to say that. I'm not sure what this
means.
Note the multiple pauses in the server timeline, as the resolver seems
to go quiet.
can anyone reproduce this result, or help me to interpret the logs?
I'm unable to reproduce this, unfortunately, and that makes finding the
cause harder. Does it often happen to you?
There's one probably unimportant thing that puzzles me in the log - the
plan to find www.ietf.org AAAA at 15:29:25. It happens when the clients
you show only have asked one request - for www.ietf.org A. It appears
as if some client has asked it explicitly precisely at that time - is
that possible?
You are right that 'ns1.yyz1.afilias-nst.info.' type 'AAAA' is what got
stuck. Root hints never (fully) answer that - they may only serve as
the first step in resolution chain. I think there might be a badly
handled dependency loop somewhere among the sub-requests, but I'm
currently unable to pinpoint how exactly that might happen.
Still, thanks for the report.
--Vladimir