Chronyd for Clock Synchronization with MariaDB Xpand

Overview

After installing Xpand, you will need to verify that chronyd is running so that the nodes system clocks will remain synchronized. For additional information about how to complete the initial installation and general configuration instructions, see "Deploy Xpand Topology".

Xpand requires that system clocks to be in synch to perform upgrades and so that log timestamps can be correlated. Xpand will generate database elerts if the clocks skew too much between nodes in a cluster. For additional information, see "Email Alerts for MariaDB Xpand".

The Xpand installer automatically installs and configures chronyd. To verify chronyd is running correctly:

shell> /opt/clustrix/bin/clx cmd 'chronyc tracking'

sample result:

------------------------------------------------------------------------------
--------------------------------------------------------------------------------
{nid: 1, hostname: karma050, ip: 10.2.15.127}
Reference ID    : 0A020103 (srv2.example.com)
Stratum         : 4
Ref time (UTC)  : Wed Feb 24 18:35:48 2021
System time     : 0.000007166 seconds slow of NTP time
Last offset     : -0.000009057 seconds
RMS offset      : 0.000027733 seconds
Frequency       : 3.972 ppm fast
Residual freq   : -0.001 ppm
Skew            : 0.030 ppm
Root delay      : 0.044349484 seconds
Root dispersion : 0.019681389 seconds
Update interval : 512.4 seconds
Leap status     : Normal
 polling server every 64 s

Example output of chronyd not running properly:

506 Cannot talk to daemon

You can verify that the clocks are in sync between the nodes with the following command (this assumes that the clx tool is able to properly authenticate between nodes):

shell> /opt/clustrix/bin/clx cmd 'date'

You can similarly verify ntp on all nodes with the following command:

shell> /opt/clustrix/bin/clx cmd 'ntpstat'