Re: [Ntp] Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)

Doug Arnold <doug.arnold@meinberg-usa.com> Fri, 08 January 2021 15:27 UTC

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From: Doug Arnold <doug.arnold@meinberg-usa.com>
To: Martin Burnicki <martin.burnicki@meinberg.de>, Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>, "mlichvar@redhat.com" <mlichvar@redhat.com>, "emmanuel.fuste@thalesgroup.com" <emmanuel.fuste@thalesgroup.com>
CC: "ntp@ietf.org" <ntp@ietf.org>, "magnus@rubidium.se" <magnus@rubidium.se>
Thread-Topic: [Ntp] Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)
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Date: Fri, 08 Jan 2021 15:27:20 +0000
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Subject: Re: [Ntp] Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)
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When I first heard of leap seconds I thought it was a terrible idea, a clumsy hack.  Since then I've come to understand that database and other application programmers are not timing people and often don't handle the possibility of leap seconds, or don't handle it correctly.  I believe that Google and other large data center companies have figured out that it causes less problems to mess up the time for a while than to have leap seconds.

Doug

On 1/8/21, 10:22 AM, "Martin Burnicki" <martin.burnicki@meinberg.de> wrote:

    Doug Arnold wrote:
    > I think that the point of a leap smear is that no special handling of leap seconds is needed by the client.  It is introduced gradually over a number of polling periods.

    That's exactly the point. You want to hide the leap second from the
    client to avoid that *applications* run into problems when the kernel
    just steps the time back by 1 second.

    Martin
    -- 
    Martin Burnicki

    Senior Software Engineer

    MEINBERG Funkuhren GmbH & Co. KG
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