Openstack installation : NTP on all nodes

Had followed steps given in https://docs.openstack.org – Content mostly from openstack.org – This is just a compilation on steps followed by me.  Minor changes may be observed as I had installed on Debian 9.6.

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Need : Synchronize services among nodes. Configure the controller node to reference more accurate (lower stratum) servers and other nodes to reference the controller node.

Install chrony on all nodes.

apt install chrony

On controller node :

Edit /etc/chrony/chrony.conf and add the following

server 0.asia.pool.ntp.org iburst   #(Use any NTP server details)
allow 10.0.0.0/24                   #(Let other nodes be able to connect to daemon)

On other nodes :

server controller iburst           #(Note : controller is the hostname configured)
#pool 2.debian.pool.ntp.org iburst #(Comment out the existing default pool configuration)

On all nodes restart chrony

service chrony restart

Verify on controller

root@controller:~# chronyc sources
210 Number of sources = 6
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- 139.59.50.38                  2   6    27    11  +1373us[+1373us] +/-   56ms
^* fwdns2.vbctv.in               2   6    17    12   -105us[ -360us] +/-   98ms
^? maa1.m-d.net                  0   6     0     -     +0ns[   +0ns] +/-    0ns
^? 2400:6180:100:d0::2d5:50>     0   6     0     -     +0ns[   +0ns] +/-    0ns
^? 2406:da1a:200:7201:d9ea:>     0   6     0     -     +0ns[   +0ns] +/-    0ns
^- ntp.hkg10.hk.leaseweb.net     2   6    17    12  -3165us[-3165us] +/-  272ms

root@controller:~# chronyc clients
Hostname                      NTP   Drop Int IntL Last     Cmd   Drop Int  Last
===============================================================================
aserver                        10      0   5   -    37       0      0   -     -
iserver                         4      0   1   -    27       0      0   -     -

Verify on other nodes

root@aserver:/home/sandeep# chronyc sources
210 Number of sources = 1
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^* controller                    3   6     7     1   -133ns[  +45us] +/-   58ms

root@iserver:~# chronyc sources
210 Number of sources = 1
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^* controller                    3   6     7     2    +38us[-1128us] +/-   58ms