How often do Tanzu Application Service (TAS) for VMs sync time with NTP server

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

Until VMware Tanzu Application Service (TAS) for VMs 2.3, BOSH Director and BOSH-deployed VMs sync time with the the NTP server by executing nptdate from crontab every 15 minutes. 

Since TAS for VMs 2.4, VMs system clock sync is managed by chronyd daemon instead of ntpdate.

Environment

Product Version: 2.8

Resolution

Since Tanzu Application Service for VMs 2.4, VMs system clock sync is managed by chronyd daemon instead of ntpdate. Chronyd syncs with the NTP server at variable intervals, you may check how it works in VM with `chronyc tracking` command. For further details, please refer https://chrony.tuxfamily.org/. 

$ chronyc tracking
Reference ID    : 10.193.62.2 (10.193.62.2)
Stratum         : 4
Ref time (UTC)  : Tue Apr 21 15:24:43 2020
System time     : 0.000060145 seconds slow of NTP time
Last offset     : -0.000040778 seconds
RMS offset      : 0.000366906 seconds
Frequency       : 3.509 ppm slow
Residual freq   : -0.027 ppm
Skew            : 1.783 ppm
Root delay      : 0.029378 seconds
Root dispersion : 0.039404 seconds
Update interval : 64.5 seconds
Leap status     : Normal

Checklist:

Until Tanzu Application Service (TAS) for VMs v2.3, BOSH director and BOSH-deployed VMs sync time with NTP server by executing nptdate from crontab every 15 minutes. 

 

Since Tanzu Application Service v2.4, VMs system clock sync is managed by chronyd daemon instead of ntpdate. Chronyd syncs with NTP server at variable intervals, you may check how it works in VM with `chronyc tracking` command. For further details, please refer https://chrony.tuxfamily.org/. 

$ chronyc tracking
Reference ID    : 10.193.62.2 (10.193.62.2)
Stratum         : 4
Ref time (UTC)  : Tue Apr 21 15:24:43 2020
System time     : 0.000060145 seconds slow of NTP time
Last offset     : -0.000040778 seconds
RMS offset      : 0.000366906 seconds
Frequency       : 3.509 ppm slow
Residual freq   : -0.027 ppm
Skew            : 1.783 ppm
Root delay      : 0.029378 seconds
Root dispersion : 0.039404 seconds
Update interval : 64.5 seconds
Leap status     : Normal