Nodes need a shared view of current authority#
A scheduler, partition coordinator, metadata manager, or primary writer may need one leader. If A becomes unreachable, B and C must decide whether to replace it and ensure A cannot later act with stale authority.
Terms or epochs distinguish generations. Failure detection, voting rules, and majority requirements belong to the coordination protocol - not an ad hoc “first node to notice wins” rule.
Related practice problems
Use the manifest-backed prompts below to apply this lesson in a complete design.
- In Search of an Understandable Consensus AlgorithmUSENIX / Stanford
- Reliability design patternsMicrosoft Azure Architecture Center
Reach this point to mark the lesson as read.