Re: [Ntp] Finding leap-seconds.list

[Paul Eggert <[e-mail]>]

On 11/8/18 8:40 PM, Thomas Peterson wrote:
> I was intending to keep the scope of this discussion solely on what is 
> hosted under the ietf.org domain.

Although the intent was that leap-seconds.list (as part of tzdb) be 
distributed via iana.org URLs, it is also distributed under ietf.org 
because  <https://data.iana.org/time-zones/> and 
<https://www.ietf.org/timezones/> are clones.

I don't know why the ietf.org URLs exist. I don't even recall knowing 
about them until this discussion. However, it appers that access via 
ietf.org is common. If I search Google for "leap-seconds.list" the first 
hit is the ietf.org copy (the iana.org copy isn't even in the top ten), 
and I sent ietf.org URLs to you in my previous email because I Googled 
for files without noticing that the resulting URLs were ietf.org and not 
iana.org.

In looking for why people seem to prefer ietf.org URLs, I see that NTP 
started using them for leap-seconds.list in NTP version 4.2.8p9 
(2016-11-21) presumably because the nist.gov URLs were so flaky. My 
guess is that the NTP developer in question didn't know that iana.org 
was intended and ietf.org was (at least from the tzdb point of view) 
accidental. I assume we can file a bug report with the NTP developers to 
replace ietf.org URLs with iana.org URLs, though it will take some time 
for any such change to trickle out to real-world use.

If the intent is to decommission the ietf.org URLs, I think we're all 
agreed that we should give NTP and other downstream users sufficient 
advance notice of the switch. I also suggest redirecting 
leap-seconds.list (and other tzdb-related) HTTPS requests from ietf.org 
to iana.org after the decommission occurs.

I will ask the iana.org webmasters why there are ietf.org clones of the 
URLs in question. Quite possibly there's a good reason that I don't know.


> There also does not appear to be links from the IANA time zone page 
> you link nor from any of the downloads that contain specific reference 
> to the second and third links in your email, so could you please 
> clarify how those are announced? 

Tzdb releases are announced on [e-mail] which is described 
at <https://mm.icann.org/mailman/listinfo/tz-announce>. (I don't know 
why the mailing list is archived is at icann.org and not iana.org; I 
suppose that's another question I can ask the iana.org webmasters, if 
there's interest.)

The most recent tzdb release announcement is archived at 
<https://mm.icann.org/pipermail/tz-announce/2018-October/000052.html>. 
Releases are distributed via HTTPS (also plain HTTP or FTP, but these 
are deprecated). Each release announcement contains GPG checksums for 
the release files, so the leap-seconds.list file in each distribution 
can be checked by verifying these checksums.