If you require maximum system robustness, configure your vRealize Automation system for high availability in accordance with VMware guidelines.
vRealize Automation Appliance
The vRealize Automation appliance supports active-active high availability. To enable high availability for these appliances, place them under a load balancer. For more information, see Configuring Your Load Balancer. Beginning with the 7.0 release, the appliance database, and vRealize Orchestrator are automatically clustered and available for use.
vRealize Automation Directories Management
Each vRealize Automation appliance includes a connector that supports user authentication, although only one connector is typically configured to perform directory synchronization. It does not matter which connector you choose to serve as the sync connector. To support Directories Management high availability, you must configure a second connector that corresponds to your second vRealize Automation appliance, which connects to your Identity Provider and points to the same Active Directory. With this configuration, if one appliance fails, the other takes over management of user authentication.
In a high availability environment, all nodes must serve the same set of Active Directories, users, authentication methods, etc. The most direct method to accomplish this is to promote the Identity Provider to the cluster by setting the load balancer host as the Identity Provider host. With this configuration, all authentication requests are directed to the load balancer, which forwards the request to either connector as appropriate.
For more information about configuring Directories Management for high availability, see ../com.vmware.vrealize.automation.doc/GUID-315FEC33-6224-48AE-A10E-7CF0B125CC81.html.
Infrastructure Web Server
The Infrastructure Web server components all support active-active high availability. To enable high availability for these components, place them under a load balancer.
Infrastructure Manager Service
The manager service component supports active-passive high availability. To enable high availability for this component, place two manager services under a load balancer. Because two manager services cannot be active simultaneously, disable the passive manager service in the cluster and stop the Windows service.
If the active manager service fails, stop the Windows service, if it is not already stopped under the load balancer. Enable the passive manager service and restart the Windows service under the load balancer. See Install the Primary Manager Service.
Agents support active-active high availability. For information about configuring agents for high availability, see the vRealize Automation configuration documentation. Check the target service for high availability.
Distributed Execution Manager Worker
A Distributed Execution Manager (DEM) running under the Worker role supports active-active high availability. If a DEM Worker instance fails, the DEM Orchestrator detects the failure and cancels workflows that the DEM Worker instance is running. When the DEM Worker instance comes back online, it detects that the DEM Orchestrator has canceled the workflows of the instance and stops running them. To prevent workflows from being canceled prematurely, leave a DEM Worker instance offline for several minutes before you cancel its workflows.
Distributed Execution Manager Orchestrator
DEMs running under the Orchestrator role support active-active high availability. When a DEM Orchestrator starts, it searches for another running DEM Orchestrator.
If it finds no DEM Orchestrator instances running, it starts running as the primary DEM Orchestrator.
If it does find another running DEM Orchestrator, it monitors the other primary DEM Orchestrator to detect an outage.
If it detects an outage, it takes over as the primary instance.
When the previous primary instance comes online again, it detects that another DEM Orchestrator has taken over its role as primary and monitors for failure of the primary Orchestrator instance.
vRealize Automation Appliance Database Server
The appliance database is automatically clustered within the vRealize Automation appliance. In the event of a failure, you must promote a node to be the new master on the Virtual Appliance Management Console tab.
Prior versions of the product that use an external database are still supported. If a deployment has been upgraded from 6.2 and uses an external database, VMware recommends migrating the database to an internal configuration. For more information about migrating the database and setting up appliance database replication, see the vRealize Automation 6.2 product documentation.
MSSQL Database Server for Infrastructure Components
Use an SQL Server Failover Cluster instance for high availability. vRealize Automation does not support AlwaysOn Availability Groups because the Microsoft Distributed Transactions Coordinator is used.
An internal highly-available instance of vRealize Orchestrator is supplied as part of the vRealize Automation appliance. If you require an external instance of vRealize Orchestrator, you can configure vRealize Orchestrator in an active-active mode under a load balancer. See the vRealize Orchestrator documentation.