Stephen Colebourne wrote: > On 19 July 2018 at 11:24, Martin Burnicki <[email protected]> wrote: >> As far as I know, UTC-SLS is done locally on a client, and since it's >> implemented in a Java runtime it is only "seen" by Java applications. >> >> This means if you get timestamps in Java and non-Java applications on >> the same machine then they may be off by up to 1000 s at the end of the >> UTC-SLS smear interval, isn't it? >> >> If you have a smearing NTP server then all clients of the same server >> will have the same smeared time, which is of course off UTC during the >> smear interval, but at least all Java and non-Java applications on a >> particular machine will see the same system time. >> >> I think it depends on the requirements of the applications which way is >> to be preferred. > > True, but the point is that we have already, and are likely to have > more in the future, boundaries that want different representations. > Specifically, cases where a low level system understands and models > leap seconds, but a high level system does not want to (for various > perfectly good reasons). Once it is accepted that there are two > representations, and both are valid, there is a need to convert > between the two. > > For the plan to work fully it needs to be possible for any of these > setups to be valid (and maybe more options too): > > - network clock returns UTC, OS handles UTC, application/framework handles UTC > - network clock returns UTC, OS handles UTC, application/framework smears > - network clock returns UTC, OS smears, application/framework unaware > - network clock smears, OS unaware, application/framework unaware > > Getting the smear off the network and into the OS will undoubtably be > useful in some use cases, but they are not the only use cases.
I fully agree, and that's what I meant by "it depends on the requirements of the applications". ;-) Martin -- Martin Burnicki Senior Software Engineer MEINBERG Funkuhren GmbH & Co. KG Email: [email protected] 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 _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
