Citrix officially recommends using SQL Server Always On Availability Groups for ensuring high availability for the Workspace Environment Management (WEM) database. This feature provides a robust, database-level failover solution, ensuring that the WEM service remains operational in the event of a database server failure. The WEM database creation wizard and configuration utilities have built-in support for specifying an availability group listener, simplifying the setup in a high availability environment.

B. Mirroring: While database mirroring is a supported option, it is a deprecated SQL Server feature. Always On Availability Groups are the modern, recommended successor for high availability.

C. Replication: SQL Server Replication is designed for data distribution and scaling out read workloads, not as a primary high availability solution for rapid, automatic failover of a transactional database.

D. Clustering: SQL Server Failover Cluster Instances (FCI) provide instance-level high availability. However, Citrix documentation specifically highlights and recommends Always On Availability Groups for database-level protection.

1. Citrix Product Documentation. (2023). Workspace Environment Management 2305: System requirements. "Database" section. Retrieved from Citrix Docs.

Quote/Reference: "For high availability, you can use SQL Server Always On availability groups. We recommend that you run the WEM database in a high availability environment. Set up the WEM database with Always On availability."

2. Microsoft SQL Server Documentation. (2023). Database Mirroring (SQL Server). Retrieved from Microsoft Learn.

Quote/Reference: "This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. We recommend using Always On availability groups instead." This supports why Mirroring is not the recommended option.