Why is everyone classified in the internal workgroup?

A PFE colleague recently posted a question describing what seemed like a weird and unexpected situation he observed while he was onsite in one customer.

From SQL Server Management Studio, every single entry in the Processes section of the Activity Monitor showed as being classified as the “internal” in the “Workload Group” column, just like the screenshot below shows:


None of the reasons exposed by Bob in How It Works: Resource Governor ‘INTERNAL’ Group seemed appropriate for this particular case, since my colleague was observing it wasn’t a temporary condition at all.

What that post doesn’t explain is that there are two possible conditions under which each and EVERY session is classified as internal for their whole existence. Those two reasons are when the instance monitored corresponds to:

  1. an Enterprise SKU with trace flag 8040 enabled via a –T startup parameter, or
  2. an SKU for which RG is disabled (ie anything other than Evaluation, Developer, or Enterprise editions)

In either of those two cases, every session is classified in the same internal group, and never changes to any other (whether default or a user-defined one.)