Bug#773252: systemd-timesyncd syncs time about once per minute

[Michael Biebl]

Am 16.12.2014 um 14:07 schrieb Michael Biebl:
> Am 16.12.2014 um 04:45 schrieb Jos van Wolput:
>> Package: systemd
>> Version:  215-8 and 218-1
>> Severity: normal
>>
>> Dear Maintainer,
>>
>> Systemd-timesyncd syncs time about once per 60 seconds.
> 
> What makes you think systemd-timesync syncs the clock once every 60 seconds?

I just studied the code and timesyncd starts with a minimal 32 second
interval (NTP_POLL_INTERVAL_MIN_SEC) which is increased until it reaches
the maximum 2048 second polling interval (NTP_POLL_INTERVAL_MAX_SEC). It
seems to use an exponential like back-off algorithm as shown by the journal

> Dez 16 14:07:41 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 32s/+0.253s/0.028s/0.000s/+500ppm
> Dez 16 14:08:13 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 64s/-0.005s/0.025s/0.002s/+460ppm
> Dez 16 14:09:17 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 128s/-0.022s/0.040s/0.008s/+373ppm
> Dez 16 14:11:25 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 128s/-0.053s/0.024s/0.050s/+165ppm
> Dez 16 14:13:33 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 256s/+0.030s/0.124s/0.055s/+165ppm (ignored)
> Dez 16 14:17:50 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 256s/-0.056s/0.026s/0.052s/+55ppm
> Dez 16 14:22:06 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 512s/-0.012s/0.025s/0.050s/+43ppm
> Dez 16 14:30:38 pluto systemd-timesyncd[12409]: interval/delta/delay/jitter/drift 1024s/+0.046s/0.149s/0.059s/+43ppm (ignored)

roughly 30s -> 1m, 1m -> 2m, 2m -> 4m, 4m -> 8m ...

This looks like a sensible approach to me.



-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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