4: Consistency
- Page ID
- 58514
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- 4.2: Constraints and Interface Consistency
- Definition of constraints; overview of the models of consistency for maintaining constraints discussed in this chapter: strict vs eventual consistency.
- 4.3: Cache Coherence
- Methods of maintaining either strict or eventual consistency for one or multiple caches, in the form of read/write coherence: write-through caches, timer expiration, marking variables with a "fluorescent pen," the snoopy cache.
- 4.4: Durable Storage Revisited - Geographically Separated Replicas
- Considerations for enhancing durable storage by geographically separating replicas. Includes discussion of replicated and single state machines, maintaining data integrity with witnesses, and majorities/quorums in reading replicas.
- 4.5: Reconciliation
- The process of reconciliation, or repairing differences between replicas intended to be identical. Includes discussion of occasionally connected operation, writing a simple reconciliation algorithm, and possible improvements to this algorithm.
- 4.6: Perspectives
- Brief discussion of the historical context of systematic applying atomicity to recovery and coordination. The tradeoffs between concurrency and complexity of a coordination scheme. Areas for further study in this field, such as compensation and achieving consensus in the face of hostile behavior.