"SQL Server AlwaysOn" is a marketing term which refers to the high availability and disaster recovery solution introduced when SQL Server 2012 was launched.
Most commonly this term is used to reference Always On Availability Groups https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/overview-of-always-on-availability-groups-sql-server?view=sql-server-2017
An availability group supports a replicated environment for a discrete set of user databases, known as availability databases. You can create an availability group for high availability (HA) or for read-scale. An HA availability group is a group of databases that fail over together. A read-scale availability group is a group of databases that are copied to other instances of SQL Server for read-only workload. You can provide client connectivity to the primary replica of a given availability group by creating an availability group listener. An availability group listener provides a set of resources that is attached to a given availability group to direct client connections to the appropriate availability replica. An availability group listener is associated with a unique DNS name that serves as a virtual network name (VNN), one or more virtual IP addresses (VIPs), and a TCP port number.
Does Identity Manager support Microsoft SQL Server AlwaysOn?
Microsoft SQL Always On has been certified and is fully supported.
https://techdocs.broadcom.com/us/en/symantec-security-software/identity-security/identity-manager/14-4/platform-support-matrix/Support-for-SQL-Always-On-Availability-Group.html