[Twisted-Python] a question about monotonic clock

Tristan Seligmann mithrandi at mithrandi.net
Sun Oct 28 18:16:09 EDT 2012

On Mon, Oct 29, 2012 at 12:05 AM, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> This depends on how you're running ntpd. If you have "-x" on the command
> line, yes - ntpd will not step.
> If not, there are circumstances it will step - clock diffs in excess of
> 128ms iirc?

If an offset of 128ms occurs at any time other than initial ntpd
startup (which will presumably occur at system startup), that means
you've either experienced a significant period of time without
connectivity to time servers[1], you have a hardware / kernel issue
that should be resolved, or some other software on the system is
messing with the clock. Aside from network issues, the other
possibilities are all serious issues that should be corrected, not
tolerated as a normal situation.

> Who knows what newer implementations like chrony or openntpd do!

If they're doing something silly, then maybe you shouldn't use them.

[1] Well, haha, just kidding; if this happens, then ntpd will remove
the servers as being unreachable, and terminate once they have all
been removed, thus resulting in the need to restart ntpd...
mithrandi, i Ainil en-Balandor, a faer Ambar

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