Availability Groups are Microsoft’s HA/DR solution for the present and the future. While many companies have adopted them using SQL Server 2012 and 2014, there were reasons other companies didn’t. With SQL Server 2016, Microsoft is addressing several of these.
One of the biggest barriers was no Standard-Edition equivalent. Without the ability to create an AG in Standard, many companies continued to use Failover Clustering or Database Mirroring as an HA solution. 2016 introduces the “Basic Availability Group”. It’s an exciting addition, but this is not a full-fledged, multi-replica, HA/DR/reporting solution as available in Enterprise Edition. Here are the current limitations:
- Only two replicas can participate in the AG.
- A secondary replica can’t be used for backups or read access.
- Only one database per AG.
- The AG can’t be upgraded – if you move to Enterprise Edition, you have to drop and recreate the AG.
As you can see, this is primarily meant as a replacement for Database Mirroring. The primary benefit of an AG over DBM is that the AG can be set up as synchronous or asynchronous. It can be used for HA or DR, without having to use an “advanced” Enterprise Edition AG.
You can still use the GUI, T-SQL, and PowerShell to create the AG. You are also able to configure a listener.
Interested in learning more about how Basic Availability Groups could meet your company’s needs? Please contact me today!