You can configure the vRealize Automation IaaS Manager Service to automatically fail over to a backup if the primary Manager Service stops.
Starting in vRealize Automation 7.3, you no longer need to manually start or stop the Manager Service on each Windows server, to control which serves as primary or backup. Automatic Manager Service failover is disabled by default when you upgrade IaaS with the Upgrade Shell Script or using the IaaS Installer executable file.
When automatic failover is enabled, the Manager Service automatically starts on all Manager Service hosts, including backups. The automatic failover feature allows the hosts to transparently monitor each other and fail over when necessary, but the Windows service must be running on all hosts.
You are not required to use automatic failover. You may disable it and continue to manually start and stop the Windows service to control which host serves as primary or backup. If you take the manual failover approach, you must only start the service on one host at a time. With automatic failover disabled, simultaneously running the service on multiple IaaS servers makes vRealize Automation unusable.
Do not attempt to selectively enable or disable automatic failover. Automatic failover must always be synchronized as on or off, across every Manager Service host in an IaaS deployment.