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UCCX Failover and NTP

According to what I've found in UCCX 9.0 installation guides, the secondary node in a HA installation looks at the primary for NTP. What happens in the case of failover when the primary is unavailable?

Thanks in advance,


Cisco Employee

When you issue a "show ntp status" on the secondary node, it in fact does list the primary node's address as its NTP source.  This is true whether the secondary node is Slave or Master.

With that, in the event of a failover between UCCX nodes, as long as the primary node was reachable on the network, the secondary will continue to sync its clock to it.

However, if the primary is offline all together, then this would mean that the secondary's clock could start to drift.  This is no different in a healthy UCCX HA pair when the NTP servers go offline and then the Primary's clock starts to drift.

I'm not positive on what this looks like in production, but I would suspect it's not critical for the secondary to keep processing calls.  It doesn't depend on the time on any other server to function properly.  Maybe the log files will have timestamps which do not line up with your CUCM log files.

Since we're on the topic of extended outages, if you do take a large enough hit to your primary node that you are worried about time drift, then you also have to consider this in an HAoW environment:

Data in Agent Datastore, Historical Datastore and Repository Datastore of Informix IDS database start merging after the network partition is restored and this could potentially generate heavy data traffic over the WAN. Cisco recommends restoring the WAN link during after hours to minimize the performance impact.

Source: UCCX SRND, Page 4-12

Anthony Holloway

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If NTP is unreachable for the primary for an extended amount of time, (I see a critical error triggered) would this cause a failover?


I'm going to be honest and say that I don't know.  I'll try to research that for you, but I'm not sure I've ever seen a list of reasons why a failover can occur.

Anthony Holloway

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