Demo: a quorum read returning stale data, explained
On This Lesson 3 topics
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In this lesson
trace how a read can be stale although R + W > N appears satisfied.
Draft outline details
Step by step
- Set up N=3, W=2, R=2 and write a stock value of 10.
- Introduce a slow replica and a sloppy-quorum or hinted-handoff write.
- Show the read returning the old stock value of 12.
- Planned mistake: blame the client for the stale read; fix by tracing which replicas formed each quorum.
- Choose a remedy: strict quorums, read repair, or a different store for stock.
Prepares SRB-003-LAB1.
Practice
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