Distributed transactions in Azure SQL Managed Instance
A distributed transaction is a database transaction in which there are two or more database servers involved. In an on-premises computer running SQL Server, this is managed by the Microsoft Distributed Transaction Coordinator (MSDTC) process. Microsoft recently announced support for distributed transactions in SQL Managed Instance, and this feature is available in preview. Since the MSDTC service is not available for Platform-as-a-Service in Azure, this feature is directly integrated with Azure SQL Managed Instance.
Before you run a transaction across multiple instances, first you need to add all the instances into a mutual security and communication relationship. This can be done by creating a Server Trust Group between all the instances using the Azure portal. If the instances are not part of the same virtual network, then Virtual Network Peering (discussed in Chapter 9, High availability and disaster recovery) is required...