Frequency of the NTP queries

1st Official Post

    Hi!

    I use LibreElec (9.2.6 RPi2.arm) on Raspberry Pi 3b and after I included Pi-Hole in my network I noticed how many queries my LibreElec produces in my network. Specifically, there are on average about 20 NTP queries per minute. It seems to me a lot. I don't see the purpose of having so tight interval controlling the right time. Is this normal behavior? Can I somehow reduce the frequency of NTP queries? From my point of view once or twice in 24h should be enough.

    Hope this is the right subforum here.

    TIA,

    Gunnar

    Quote from CvH

    do you block the ntp queries or do they succeed?

    if the system can't find a working ntp it is normal that it tries frequently

    I don't block those queries, but I have no idea, how to control do they succeed or not

    • Official Post

    ^ running "journalctl | grep ntp" on an idle Amlogic device in the network here shows a check every 17 mins; more frequent than I would have expected but also nothing too extreme. It's not 20/minute though. Can you corroborate that frequency with journal entries?

    Quote from chewitt

    running "journalctl | grep ntp" on an idle Amlogic device

    grepping ntp from journalctl gave me no output. Before the original posting, I looked into /var/log, but this directory is completely empty. Is there any logging mechanism I am not aware of?

    To test do the ntp-queries succeed, I set the system clock an hour too early, but after running a few hours it remains wrong. So seems, that the problem may be in unsuccessful ntp-calls.

    Then I checked LE Network settings and noticed that Timeserver#-settings were actually empty. I set first as pool.ntp.org and after restart, I got from journalctl also ntp-set logging:

    Code
    Apr 11 19:28:50 pildikast connmand[301]: ntp: adjust (jump): +65148582.224308 sec

    This seems strange to me, but before setting up the timeserver-setting, it polled different nodes in pool.ntp.org but did not actually set the local clock. But now it does and does not pollute my Pi-Hole's log with not relevant queries.

    Seems, we can close the case. Thank you all for the input!

    Wbr,

    Gunnar

    • Official Post

    For the record, on my RPi4 NTP is going off every 17m04s.

    Code
    May 05 18:21:12 rpi4c connmand[507]: ntp: adjust (slew): +0.007657 sec
May 05 18:38:16 rpi4c connmand[507]: ntp: adjust (slew): -0.013000 sec
May 05 18:55:20 rpi4c connmand[507]: ntp: adjust (slew): +0.004329 sec
May 05 19:12:24 rpi4c connmand[507]: ntp: adjust (slew): -0.008639 sec