MultiSubnetFailover for BizTalk 2020

[JonSidnell_ClusterUK]

Hi,

We're implementing an HA installation of BizTalk Server 2020 on Azure with Always On Availability Group for SQL Server. We are trying to work out whether we need to use a Load Balancer in front of the SQL cluster. The BizTalk Server documentation says that MultiSubnetFailover available since .NET 4.6.2 is not supported (High Availability using SQL Server Always On Availability Groups - BizTalk Server | Microsoft Docs) since BizTalk Server uses Microsoft OLE DB to connect to the database which has been the case since BizTalk 2016. We've also found this post (MultiSubnetFailover connection option in BizTalk - Microsoft Tech Community) which suggests that this may have changed in BizTalk 2020.

Has anyone tried getting this working with BizTalk 2020?

Thanks
Jon
Jon

[#2]

Note: I believe that the post MultiSubnetFailover connection option in BizTalk that says you can do it with the WCF-SQL Adapter, and not the connection the Host Instances make to the BizTalk Database. It also states "BizTalk Server does not set this connection option in the connection string when connecting to BizTalk Databases in SQL Availability Group or Failover Clustering Instance."

[#3]

BizTalk currently does not use this option. Personally for the quickest (reduce locks as well) and most highly available I would recommend SQL Failover Cluster Instance (FCI), classic Active/Passive cluster. SQL FCI only use one shared storage which is faster than having to wait for SQL AO AG primary and secondary nodes to do the sync operation (CPU and network overhead). In Azure you can use the newer Azure Shared Disk as shared storage for SQL FCI and MSDTC.