Re: [Ntp] Finding leap-seconds.list

I propose the following occurs if the working group agrees:

* draft-ietf-ntp-bcp is updated to remove reference to the IETF hosted 
leap second file (as has already been suggested)
* The IETF ceases to host unpacked versions of tzdb
* Updates sent to various other mailing lists that may be affected by 
this change (off the top of my head, tz@iana.org, pool@lists.ntp.org, 
freebsd-ports@lists.freebsd.org) as a matter of courtesy before its 
hosting is removed.

Regards

On 08/11/2018 01:28, Dieter Sibold wrote:
>
>
> On 8 Nov 2018, at 2:17, Denis Reilly wrote:
>
>> Thomas and Martin,
>>
>> On doing my own research into this for the BCP, I found that the Time 
>> Zone database maintenance procedures are documented in BCP 175 / RFC 
>> 6557.
>>
>> However, after the discussion during the WG meeting, I think it's 
>> better to remove the mention of the leap second file hosted by the 
>> IETF in the BCP. As Martin notes, there are better places to get it.
> I agree with Denis.
>
>>
>> -- 
>> Denis Reilly  |  Technical Lead  |  denis.reilly@orolia.com 
>> (585)321-5837
>>
>> -----Original Message-----
>> From: ntp <ntp-bounces@ietf.org> On Behalf Of Martin Burnicki
>> Sent: Wednesday, November 07, 2018 1:00 PM
>> To: Thomas Peterson <hidinginthebbc@gmail.com>; ntp@ietf.org
>> Cc: Paul Eggert <eggert@cs.ucla.edu>
>> Subject: Re: [Ntp] Finding leap-seconds.list
>>
>> Thomas Peterson wrote:
>>> As was discussed at the working group meeting at IETF 103 [0], I 
>>> have decided to do some research on the leap-seconds.list file that 
>>> the IETF appears to be hosting at 
>>> https://www.ietf.org/timezones/data/leap-seconds.list, but for some 
>>> participants of this working group appear unclear about.
>>
>> During the IETF NTP WG session I posted a link in the chat which 
>> points to a PDF I wrote some time ago:
>> https://www.meinbergglobal.com/download/burnicki/the_ntp_leap_second_file.pdf 
>>
>>
>> There are several "original" versions of that file published by the 
>> IERS, NIST, and USNO.
>>
>> One of those original files (usually the version from NIST) is used 
>> to update the TZDB records, and the original file is also included in 
>> the TZDB distribution/tar ball, which is then unpacked and made 
>> available at the IETF web site.
>>
>> The problem here is that first an update of the original leap second 
>> file appears, and only whenever the next TZDB version is released 
>> after that the file appears on the IETF web site.
>>
>> So for most users it's better to pick up a file from one of the 
>> original sites.
>>
>>> Where is this referenced in an RFC or other IETF document?
>>> I ran a search of “leap-seconds.list” across the spread of draft and 
>>> RFC documents. No RFC that I have found makes direct reference. 
>>> However, the current NTP BCP draft Section 4.6 [1] contains:
>>>
>>> ... SNIP ...
>>>
>>> The IETF maintains a leap second list [[7]] for NTP users who are not
>>>    receiving leap second information through an automatic source.
>>>
>>>    Files are also available from other sources:
>>>
>>> ... SNIP ...
>>>
>>> With [[7]] holding reference to the file hosted at, and a list of 
>>> links to sources.
>>>
>>> What else is www.ietf.org hosting of a similar nature?
>>> This file alone is not the only thing hosted under www.ietf.org, in 
>>> fact https://www.ietf.org/timezones/ directory listings show that 
>>> all recent versions of the tzdb (including 2018g the most recent) 
>>> which suggests a human maintaining the hosting of it, or automated 
>>> process. Versions only go back to 2016. These files are also 
>>> available over FTP [2].
>>>
>>
>> Yes, and since the leap seconds file is part of the TZDB, it also 
>> becomes available via the IETF web site.
>>
>>> How long have these files been hosted on www.ietf.org?
>>> Internet archive's Wayback Machine [3] shows it appearing back in 2015.
>>>
>>> Who is using the file?
>>> ntpd does depend on it as was discussed at the WG meeting, [4]. 
>>> FreeBSD [5] holds reference to it and users have reported issues 
>>> when being unable to access it in the past. In addition, at least 
>>> one library [6] make use of it outside of ntpd, however I don't 
>>> believe this is heavily used or cause non-developers or system 
>>> administrators any pain if it went missing.
>>
>> I'm sure the file *is* heavily used, but maybe not directly from the 
>> IETF web site.
>>
>> It's a good source to become aware of an upcoming leap second, and 
>> it's a good source to be able to determine the current UTC/TAI 
>> offset, as e.g. required when using PTP which uses TAI timestamps by 
>> default.
>>
>> Anyway, I think the file is mostly used by NTP or PTP servers since 
>> for most applications the information interesting for clients can be 
>> passed via the individual protocols.
>>
>>
>> Regards,
>>
>> Martin
>> -- 
>> Martin Burnicki
>>
>> Senior Software Engineer
>>
>> MEINBERG Funkuhren GmbH & Co. KG
>> Email: martin.burnicki@meinberg.de
>> Phone: +49 5281 9309-414
>> Linkedin: https://www.linkedin.com/in/martinburnicki/
>>
>> Lange Wand 9, 31812 Bad Pyrmont, Germany Amtsgericht Hannover 17HRA 
>> 100322 Geschäftsführer/Managing Directors: Günter Meinberg, Werner 
>> Meinberg, Andre Hartmann, Heiko Gerstung
>> Websites: https://www.meinberg.de https://www.meinbergglobal.com
>> Training: https://www.meinberg.academy
>>
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