I've been hearing about round-robin read-only routing ever since SQL 2016 came out but whenever I tried to test if it's working it never seemed to be. But now I know exactly how it works and there's a few loopholes where it may not trigger, and they're not the documented ones you're thinking of.

To test the limits of it you're going to need:

• PowerShell 5.1
• Pester 4 (Install-Module Pester -Force)
• DbData (Install-Module DbData -Force)

I'll explain any of the Pester and DbData bits along the way so don't worry. They're minor framework stuff.