Periodically I get a question about what happens to UCMA applications that are associated with one of the pools in a paired pool architecture when users are failed over to a backup pool. This can be very important since in some cases a UCMA application is serving a critical function for some part of the organization, and so they want to be sure that it will remain available in a failover situation.
Unfortunately, UCMA applications are not automatically failed over when you run the Invoke-CsPoolFailover cmdlet in Lync Server Management Shell. If a pool that is the next hop for a UCMA application goes down, and the users are failed over to the backup pool, the UCMA application will still be out of commission. This means that it’s not uncommon for UCMA applications to be overlooked in failover planning. People may assume they will fail over with everything else, while others may simply not know about the applications. If you want to include UCMA applications in your failover plan, you’ll need to plan for some additional manual steps to fail them over.