Comment by pvg
6 years ago
The idea is that the fix itself is being tested. If you knew your 'rollback' will work for certain, then you'd just deploy it to everyone asap. But since you don't, you test it and as a potential outcome of your test is no fix or making things worse, you don't test it on your highest-value customers. Imagine what your postmortem would read like if your fix made an even bigger mess.
Oh, I misunderstood you originally. I thought you said rollout from highest to lowest. You're actually saying lowest to highest.
I'm just describing what I think the sequence in the postmortem is. They were already in the poop and wanted to test their fix in a real but low-impact way.