One of our clients wants to shift to SQL Always On.
They run WAB Developer app on Portal/AGS.
Is it only a matter of redefining the connections as described in:
The APPLICATIONINTENT and MULTISUBNETFAILOVER conditions described in the support documentation refer to additional options which are available when using SQL AlwaysOn Availability Groups - you can choose not to use them in the connections, but as the article describes, this will essentially default to APPLICATIONINTENT=READWRITE and MULTISUBNETFAILOVER=NO.
The key thing when changing from a standalone server to AAG is to connect to the AAG listener instead of the database server. e.g. if the original server isGISSQL01, and we're adding GISSQL02, then there will be an AAG listener (kind of like a load balancer) in front of these servers with a DNS entry called something like GISSQL.
If the connections still refer to GISSQL01 and this server becomes unavailable, then traffic will not automatically failover to GISSQL02. This will only work as intended by connecting to the GISSQL listener.