7.1

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
the Installing vRealize Automation 7.1 documentation.
Agents
Agents support active-active high availability. For information about conguring agents for high availability,
see the vRealize Automation conguration 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 workows
that the DEM Worker instance is running. When the DEM Worker instance comes back online, it detects that
the DEM Orchestrator has canceled the workows of the instance and stops running them. To prevent
workows from being canceled prematurely, leave a DEM Worker instance oine for several minutes before
you cancel its workows.
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.
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If it nds no DEM Orchestrator instances running, it starts running as the primary DEM Orchestrator.
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If it does nd another running DEM Orchestrator, it monitors the other primary DEM Orchestrator to
detect an outage.
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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.
MSSQL Database Server for Infrastructure Components
vRealize Automation supports SQL AlwaysON groups only with Microsoft SQL Server 2016. When
installing SQL Server 2016, the database must be created in 100 mode. If you use an older version of
Microsoft SQL Server, use a Failover Cluster instance with shared disks. For more information on
conguring SQL AlwaysOn groups with MSDTC, see hps://msdn.microsoft.com/en-
us/library/ms366279.aspx.
vRealize Orchestrator
An internal highly-available instance of vRealize Orchestrator is supplied as part of the vRealize
Automation appliance.
Reference Architecture
24 VMware, Inc.