Wednesday, October 19, 2016

Cluster Time Synchronization Service (CTSS) on RAC

Cluster Time Synchronization Service (CTSS) is installed as part of Oracle clusterware.
Basically it runs in two modes,


 Observer mode

   Time synchronization service works with NTP, then CTSS must be in Observer mode.
  CRS-4700: The Cluster Time Synchronization Service is in Observer mode.


 Active mode

   When CTSS detects time sychronization service or configuration is broken on the system,  then  CTSS is in 'Active' mode.

In order to change CTSS from observer to active mode, cluster needs to be stopped. Once cluster is stopped in all nodes, stop ntp service and deconfigure the service.


Once cluster is started, CTSS will be active.
CRS-4701: The Cluster Time Synchronization Service is in Active mode.