Hi everyone. If you’re using Always On Availability Groups (AGs), Microsoft has put a few improvements/fixes in recent patches that you should be aware of.
First and foremost, SQL Server 2016 Service Pack 2 was just released today. There are two major improvements in it for AGs:
1. SQL Server 2016 now has full Microsoft Distributed Transaction Coordinator (DTC) support. SQL Server 2016 had partial support for DTC with one of the two scenarios (cross instance/cross platform), but not intra-instance DBs. SQL Server 2017 had both, and now that was backported so SQL Server 2016 supports all DTC scenarios with AGs. This is great news.
2. Fixing Service Broker so that on failovers, AGs close open connections.
In SQL Server 2017 CU6, the big change is that the distribution database in replication can now be made highly available using AGs. There are a bunch of caveats, but this is a pretty big deal. See this link for all the info. As with full DTC support, they are going to port this back to a CU for SQL Server 2016 SP2, so SQL Server 2016 will also be getting this capability.