Re: [chrony-users] Unreachable sources only updates NTPSynchronized on service start

[Bill Unruh <unruh@xxxxxxxxxxxxxx>]

That * does not mean it is synchronized. It means that it is the source that
chrony will use to try to synchronize to. Since you only gave it one source,
it has no other choice, it cannot try anything else. That is why the advice is
to use 3 or 5 sources.

Whetehr with reach=0 it should erase the * is however a valid question.



William G. Unruh __| Canadian Institute for|____ Tel: +1(604)822-3273
Physics&Astronomy _|___ Advanced Research _|____ Fax: +1(604)822-5324
UBC, Vancouver,BC _|_ Program in Cosmology |____ unruh@xxxxxxxxxxxxxx
Canada V6T 1Z1 ____|____ and Gravity ______|_ www.theory.physics.ubc.ca/

On Mon, 16 Mar 2020, Jordan Gibbens wrote:

> Hi,
>
> ]# cat /etc/redhat-release
> CentOS Linux release 8.1.1911 (Core)
>
> ]# uname -r
> 4.18.0-147.3.1.el8_1.x86_64
>
> ]# rpm -qa | grep chrony
> chrony-3.5-1.el8.x86_64
>
> I've been working with dbus and org.freedesktop.timedate1. If I purposefully stop my upstream
> NTP server that my chrony client is synchronizing to, the NTPSynchronized property never
> seems to get updated to reflect this.
>
> ]# chronyc sources
> 210 Number of sources = 1
> MS Name/IP address         Stratum Poll Reach LastRx Last sample               
> ===============================================================================
> ^? head.cluster                  3   6     0   636    -29us[  +95ns] +/- 8964us
> So the single NTP source is clearly unreachable in this scenario. Yet, I will still see
> NTPSynchronized in DBUS.
>
> # gdbus introspect --system --dest org.freedesktop.timedate1 --object-path
> /org/freedesktop/timedate1 | grep NTPSynchronized
>       readonly b NTPSynchronized = true;
>
>
> Timedatectl shows the same.
>
> ]# timedatectl 
> ...
> System clock synchronized: yes
>               NTP service: active
> And within chrony, it doesn't update leap status. Or show the server as down in the activity 
> report.
> ]# chronyc tracking | grep ^Leap
> Leap status     : Normal
> ]# chronyc activity
> 200 OK
> 1 sources online
> 0 sources offline
> 0 sources doing burst (return to online)
> 0 sources doing burst (return to offline)
> 0 sources with unknown address
>
> This behavior seems indefinite, until I restart the client side chronyd service.
> ]# systemctl restart chronyd
> ]# gdbus introspect --system --dest org.freedesktop.timedate1 --object-path /org/freedesktop/
> timedate1 | grep NTPSynchronized
>       readonly b NTPSynchronized = false;
> ]# chronyc tracking | grep ^Leap
> Leap status     : Not synchronised
> ]# chronyc activity
> 200 OK
> 1 sources online
> 0 sources offline
> ]# chronyc sources 
> 210 Number of sources = 1
> MS Name/IP address         Stratum Poll Reach LastRx Last sample               
> ===============================================================================
> ^? head.cluster                  0   8     0     -     +0ns[   +0ns] +/-    0ns
>
> If I bring the NTP source online, then restart the chronyd client, it will properly update to
>  show not synchronized, then eventually synchronized. The sync state appears to only get upda
> ted during the chronyd service startup sequence though.
>
> I really liked the idea of being able to easily show the NTP synchronization status, and this
>  is already done in the Cockpit GUI 'system' tab. Cockpit appears to use the same DBUS value 
> though, because it is not updating properly either. 
> If there is a configuration setting to force chronyd to update at intervals, without restarti
> ng the service, please let me know. I looked through all of the config options but nothing st
> ood out.
> Thank you,
> Jordan Gibbens
> Systems Engineer
> Advanced Clustering Technologies, Inc,