| Re: [chrony-users] Timeout for initstepslew? |
[ Thread Index |
Date Index
| More chrony.tuxfamily.org/chrony-users Archives
]
- To: chrony-users@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-users] Timeout for initstepslew?
- From: Zack Shivers <zack@xxxxxxxxx>
- Date: Tue, 1 Oct 2019 12:48:26 -0700
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=marble-io.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=mA4kWVPjllteQUepgFyTIFyKtvL+kNGjAG2iJ6nAAG0=; b=1eqQGkYDHp820fO6JhfosgQ1trepfjLJoA7ssEblDupCBHieQNA/9oET+MNTn7tMKK CjIhNsCz2pz0mYSxOlkrrxjt3aYBOPpd/txIspBmRjl7Qg8UFUTK9B2RRmpnPl0Cb3UY 3BeeOteXLT7hugdWbC5kbitZMJw2m0SjvmgVW+nOGTAAp7E676jny/3gW5/dJ/HWpOLV 2WgLbB+MjABBf0NXfbDm7oHaoRkU9NtHNtws2jt0XlzI6afleZ2K6Z9KkuOPxGmzThdc 2Msb727OLoU+MrBEUdovXWBsKK+uaed0hs2tz8VfstBQy2SBR3HPiYE349kIrPiOA4P9 UBtw==
> Yes, you could, at least in theory. Is the server free running (using
> local directive), or synchronized to another server? If it is not very
> stable, there is no point in trying to tightly synchronize its
> clients.
Yes, the server is free running with the local directive. I'm curious
why you say there's no point. For my application, tight
synchronization between machines is all that is required, not absolute
accuracy to an upstream time source. If host1 varies, I want host2 to
track it as closely as possible.
> Best values of minpoll/maxpoll and filter will depend on your network,
> clock, etc. Set the polling interval to the shortest one you are
> comfortable with (not overloading the network or server) and try to
> increase the filter length so that the number of samples reported in
> sourcestats is close to 64, but not 64, most of the time. If it's
> stuck at 64 most of the time, the filter and the update interval is
> probably too short.
Thank you for the practical advice. If RMS offset is a good indicator,
I seem to be getting an excellent synchronization:
RMS offset : 0.000000093 seconds
Relevant client configuration:
server 192.168.0.2 minpoll -6 maxpoll -4 xleave filter 5
On Wed, Sep 25, 2019 at 12:19 AM Miroslav Lichvar <mlichvar@xxxxxxxxxx> wrote:
>
> On Tue, Sep 24, 2019 at 01:26:01PM -0700, Zack Shivers wrote:
> > Could I gain the accuracy of shorter polling interval with added rate
> > stability by using the filter option? If so, do you have any recommended
> > values for poll and filter?
>
> Yes, you could, at least in theory. Is the server free running (using
> local directive), or synchronized to another server? If it is not very
> stable, there is no point in trying to tightly synchronize its
> clients.
>
> Best values of minpoll/maxpoll and filter will depend on your network,
> clock, etc. Set the polling interval to the shortest one you are
> comfortable with (not overloading the network or server) and try to
> increase the filter length so that the number of samples reported in
> sourcestats is close to 64, but not 64, most of the time. If it's
> stuck at 64 most of the time, the filter and the update interval is
> probably too short.
>
> --
> Miroslav Lichvar
>
> --
> To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
> with "unsubscribe" in the subject.
> For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
> with "help" in the subject.
> Trouble? Email listmaster@xxxxxxxxxxxxxxxxxxxx.
>
--
To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
with "help" in the subject.
Trouble? Email listmaster@xxxxxxxxxxxxxxxxxxxx.