CUCM server locked up when subscriber failed

[putney_m]

I am working on a CUCM 10.5 1.11900-13 HA cluster. When the subscriber server was turned off to performe maintenance on the physical host the publisher server became unresponsive. We could not log into the webpage and when we SSH'd into the server the CPU was over 50% utilized. Has anyone seen this type of behavior before?

Thanks
 

[Brian Carlson]

If your phones were registered to the subscriber before you shut it down, It's likely that the phones were failing over to register with the Publisher, which could be the reason for your high CPU. Did you see a reduction in the Publisher's CPU utilization over time?

[putney_m]

Yes, after about 5 hours the CPU seemed to return to a normal level and we were able to then log into the server's GUI.