Consider the following scenario:
• You deploy two paired Front-End pools in a Microsoft Skype for Business Server 2015 environment.
• You create many conference directories.
• You start pool failover between the two paired Front-End pools.
• There are many meetings being scheduled during the pool failover.
In this scenario, the pool failover fails.
This issue occurs because a back-end SQL stored procedure takes more than one minute to sync the change of the conference directories.