| Re: [chrony-dev] [RFC] Transparent fallback from NTP reference clock to RTC |
[ Thread Index |
Date Index
| More chrony.tuxfamily.org/chrony-dev Archives
]
- To: chrony-dev@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-dev] [RFC] Transparent fallback from NTP reference clock to RTC
- From: Christoph Schittel <christoph.schittel@xxxxxxxxx>
- Date: Thu, 03 Jul 2025 18:53:19 +0000
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1751568691; x=1752173491; darn=chrony.tuxfamily.org; h=mime-version:content-transfer-encoding:user-agent:list-post:list-id :references:in-reply-to:date:subject:to:from:message-id:from:to:cc :subject:date:message-id:reply-to; bh=R+Er/iDUMZRQvU7znzQKTIyOOMvpBhHSA2v20xgpoNc=; b=hO0t8CcpnDB7Yfdb1WrCQlELmNxRzb7BWzkTPOZgu0yqWqX8/iqaVmmdeSU1AF2tB3 ewc45+j2c2rC+6sxouD5smH+4buM1PkpQL0Iy6McaXwqUOeNkPsU3TVpFKqiGDJJOrIy jzcd/T0tLKTEJV3WB1GEOFKwpWLoCIutNvPqYBjA5RPzUpOnZzIJoM8/ML97rczNvt3s A3r4eDBxBIwTV9TlJikwh/dSFkWdQCwvdnir3GJh5pUSb+BRMrVtHDJYpiqRQAI9J5Vb wPZwmXMZHENUq2aisOVx+crut0QtqxMgZ/iGxU3rvmOJ8rGkSHW/KUqJC2CTYg5zFXQE 3qOg==
Miroslav Lichvar schrieb am Donnerstag, 3. Juli 2025 09:19:17 (+02:00):
> On Wed, Jul 02, 2025 at 09:59:39PM +0200, Christoph Schittel wrote:
> > Could you add an option to force STA_UNSYNC when reaching a settable
limit?
>
> Can you please explain the use case?
>
At the time the limit of 16s was implemented in the kernel, this was an
reasonable choice. Today for many applications even a (possible) deviation
of 1s or less may be regarded as too big and the system should be signaling
it by setting STA_UNSYNC. Reading David R. Mills documentation reads like
the syncing service should set STA_UNSYNC. The kernel setting it, when
maxerror reaches 16s was just meant as last resort.
(Remote) monitoring services could benefit, because hosts with sync
problems could be very easily detected. E.g. NAGIOS instead monitors the
clock difference between itself and remote hosts. This implies the
monitoring host has the "right" time. This could be improved by reading
remote hosts STA_UNSYNC, if it will be set when needed (which should be the
admin's choice, not the kernel's).
regards,
Christoph
--
To unsubscribe email chrony-dev-request@xxxxxxxxxxxxxxxxxxxx with "unsubscribe" in the subject.
For help email chrony-dev-request@xxxxxxxxxxxxxxxxxxxx with "help" in the subject.
Trouble? Email listmaster@xxxxxxxxxxxxxxxxxxxx.