Meet the group
You are on call for a MySQL that has to survive losing an entire site. This unit puts a real three-site group on your laptop, then names the parts you can already see, then explains the bet Bloodraven is making. By the end you can point at any pod and say what role it holds and what it is allowed to become. Then the obvious question: who decides that, and how fast?
Topics
Unit test
Quick check: can you name the active site from a status dump, say which pod the -primary Service selects, and explain why a read-only site can never be promoted?
Project
brstatus — the one-screen status reader
Write a tool that turns a MysqlFailoverGroup status into a one-screen summary and a meaningful exit code, so that from Unit 2 onward you can tell at a glance whether playground is healthy — and so you learn, the hard way, that a lagging reader is not an unhealthy group.