[chrony-users] Multiple Clock Sources Cannot Be Synchronized

[chengyechun <chengyechun1@xxxxxxxxxx>]

Hi all:

When I used chrony-4.3, I found that chronyd did not work effectively in multi-clock source scenarios.

For example, I have two clock sources, and they are both local clock sources.. The configuration is as follows:

[root@localhost ~]# chronyd -p

driftfile /var/lib/chrony/drift

makestep 1.0 3

rtcsync

allow all

local stratum 10

ntsdumpdir /var/lib/chrony

logdir /var/log/chrony

 

The configuration of the chronyd client is as follows:

[root@localhost ~]# chronyd -p

server 9.82.178.244 iburst minpoll 2 maxpoll 2

server 9.82.165.239 iburst minpoll 2 maxpoll 2

driftfile /var/lib/chrony/drift

makestep 1.0 3

rtcsync

ntsdumpdir /var/lib/chrony

logdir /var/log/chrony

 

 

The query result is as follows:

[root@localhost ~]# chronyc sources -a -v

 

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.

/ .- Source state '*' = current best, '+' = combined, '-' = not combined,

| /             'x' = may be in error, '~' = too variable, '?' = unusable.

||                                                 .- xxxx [ yyyy ] +/- zzzz

||      Reachability register (octal) -.           |  xxxx = adjusted offset,

||      Log2(Polling interval) --.      |          |  yyyy = measured offset,

||                                \     |          |  zzzz = estimated error.

||                                 |    |           \

MS Name/IP address         Stratum Poll Reach LastRx Last sample

===============================================================================

^x 9.82.178.244                 10   2    17     1  +3788ns[+3788ns] +/-  147us

^x 9.82.165.239                 10   2    17     1    -65ms[  -65ms] +/-  152us

 

 

However, when only one of the clock sources is used, the display is normal.

For example, modify the client configuration as follows:

 

 

server 9.82.178.244 iburst minpoll 2 maxpoll 2

driftfile /var/lib/chrony/drift

makestep 1.0 3

rtcsync

ntsdumpdir /var/lib/chrony

logdir /var/log/chrony

[root@localhost ~]# vim /etc/chrony.conf

[root@localhost ~]# chronyd -p

server 9.82.178.244 iburst minpoll 2 maxpoll 2

server 9.82.165.239 iburst minpoll 2 maxpoll 2

driftfile /var/lib/chrony/drift

makestep 1.0 3

rtcsync

ntsdumpdir /var/lib/chrony

logdir /var/log/chrony

 

 

It can be synchronized normally.

 

 

[root@localhost ~]# chronyc sources -a -v

 

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.

/ .- Source state '*' = current best, '+' = combined, '-' = not combined,

| /             'x' = may be in error, '~' = too variable, '?' = unusable.

||                                                 .- xxxx [ yyyy ] +/- zzzz

||      Reachability register (octal) -.           |  xxxx = adjusted offset,

||      Log2(Polling interval) --.      |          |  yyyy = measured offset,

||                                \     |          |  zzzz = estimated error.

||                                 |    |           \

MS Name/IP address         Stratum Poll Reach LastRx Last sample

===============================================================================

^* 9.82.178.244                 10   2     7     0  -4507ns[ -111ms] +/-  137us

 

 

I'm curious if this is the mechanism or if I'm missing some configuration.