This post contains information for Workflow Manager CU3. Please see KB4019220 for information workflow manager CU4.
With SharePoint 2016 supporting a minimum of SQL Server 2014 Service Pack 1, many customers have asked if they need a separate SQL Server 2012 instance for the Workflow Manager farm that supports their SharePoint installation. This post is to clarify the support for SQL versions and high availability features when Workflow Manager is used with a SharePoint farm.
SQL Version Support
When Workflow Manager is deployed for use with only a SharePoint 2016 or 2013 farm, SQL 2014, SQL 2012 and SQL 2008 R2 SP1 are supported for the database engine hosting the Workflow Manager and Service Bus databases. SQL 2014 support requires requires Workflow Manager 1.0 with CU3, Service Bus 1.1, and KB3086798. Information on supported service packs for SQL Server 2014 can be found on the Microsoft Product Support Lifecycle page.
If Workflow Manager is being used for any other purpose, only SQL 2012 and SQL 2008 R2 SP1 are supported as per Supported Platforms (Workflow Manager 1.0).
SQL High Availability Feature Support
For high availability in a single farm Workflow Manager supports either SQL Failover Clustering or Synchronous Mirroring. AlwaysOn Availability Groups are not supported.
Workflow Manager 1.0 Cumulative Update 3 (WFM CU3) is now available on Microsoft Download Center
An update is available for Service Bus for Windows Server 1.1 for the .NET Framework 4.6 (KB3086798)
Supported Platforms (Workflow Manager 1.0)
Disaster Recovery and Scope Restore in Workflow Manager 1.0
Hardware and software requirements for SharePoint Server 2016