We have struggled with an issue for more than a year related to HA over WAN. Even a brief network outage (1-2 seconds) between data centers would cause the master role to switch from the publisher to the subscriber. Mastership changed any time the nodes went into island mode. We finally found the root cause after numerous TAC cases, and I think it's worth sharing since changing the hostnames is supported.
The logic to elect the master node when recovering from island mode is:
Step 1. Check the service status of the nodes. If node 1 is IN_SERVICE and node 2 is in PARTIAL_SERVICE, node 1 becomes the master. If the states are the same (IN_SERVICE or PARTIAL_SERVICE), go to step 2.
Step 2. The hardware specification of both nodes will be checked. The server with the better specification will be handed the mastership. If the hardware specifications are the same, go to step 3.
Step 3. The publisher (i.e. node 1) will become the master if the hostname matches the PrimaryEngineComputerName in the ClusterSpecificConfig. If there is no match, go to step 4.
Step 4. Make the subscriber master.
Alright, now let's back up about 18 months. We decided to build a new cluster to migrate from version 9.0 to 10.6. The intent was to simplify the transition from CAD to Finesse. We built a new cluster on 9.0, restored from backup, changed the hostnames and IPs, and then upgraded to 10.6.
Back to the present (now on version 11.6), we finally lucked out with a TAC engineer that explained the island mode recovery process above. The engineer used the CET (Configuration Editor Tool) to check the ClusterSpecificConfig file where we discovered the primaryEngineComputerName was the hostname of our 9.0 publisher. So now we know step 3 above always fails and the subscriber is elected master as a result.
TAC advised this value is populated at the time of install and cannot be changed (even with root access). The 9.0 cluster had been offline for over a year. Therefore, the best solution was to rename the 11.6 publisher to match the primaryEngineComputerName.
In conclusion, changing the hostname is supported, but it will cause issues with HA. Ideally, the set network hostname command should be updated to also change the primaryEngineComputerName. I asked to have a caveat added to the appropriate section of the admin guide. It's unclear if this request reached the technical writing team – I never received confirmation.
Hi I have a query on CUCM 10.5 Licensing. My client wants to remove all Hard phones (Nearly 150) and want to deploy CIPC against each hard phone.Can I configure both types of phones for all the users for time being even if we do not have licenses to ...
Hello Experts,How can we modify the layout of Finesse to show only agents with Ready or Not Ready status. Our Call Center is 24/7 with more than 200 agents working in 3 different shifts. The supervisors don't want to see those agents w...
My organization has been having multiple issues with participants calling in and being able to unmute themselves during an event center, even though unmute on arrival has been selected prior to the start of the meeting. This has happened on several occasi...
Apologies I am new to QM! The QM environment has 2 servers, one base that runs the web front end and the other is an upload (voice server) which has a large disk with recordings on. I have changed the IP address in Windows on both servers. I hav...
Webex Full Client supports virtual video devices, however Webex Teams does not. I use software like XSplit VCam or ChromaCam to generate a virtual green screen for my webcam to replace background of my location. Those software products create ...