Episode 7. Consensus. Day 7 of your 12 day sprint.

Scenario: "A network split cuts your five node cluster two versus three. What happens?" The minority stops. That is safety working.

Say: "Quorum is two f plus one. Three nodes tolerate one failure. Five tolerate two. The side without majority cannot commit."

Say the commit line: "A log entry commits once a majority holds it. The leader applies it and followers learn the commit index."

Say the election line: "A candidate becomes leader with majority votes in a higher term. Two leaders in one term is impossible with correct terms."

Lab: write the quorum-loss table for three and five nodes, then write the fencing paragraph: STONITH,old-leader rejection, single-writer proof.

Bridge from Oracle: Say: "RAC voting disk and Data Guard observer solve the same split-brain. Quorum plus fencing is the universal answer."

Drill: write quorum sizes from memory: three needs two, five needs three.
Say: the minority stops writing, and that is safety, not an outage to fix.
Say the term line: higher terms reject stale leaders.
Done-check: draw election plus commit flow on one page before bed.
Depth tag tonight: Recognize on Raft log code, Debug on quorum math and fencing.

Teaser: tomorrow, Episode 8, Kubernetes. Why stateful databases refuse to behave like web pods.