Do You Have to License Your Standby SQL Server?

Businesses who need high availability and disaster recovery usually want three servers:

A primary SQL Server where all the writes & reads take place A high availability SQL Server sitting right next to the primary, in the same data center, keeping up with its writes, and A disaster recovery SQL Server sitting in another city or region, keeping up with the writes, but not necessarily in real time – the writes here are usually asynchronous

There are several different techniques we can use to keep those in sync, like failover clustering, Always On Availability Groups, SAN replication, log shipping, and