CAP Theorem

Kind: model

Layer: Causality Core

Record: architecture:cap-theorem

Severity: contextual

Scope: distributed state, consistency, availability

Canonical: Ontology

A conceptual representation of the choice a distributed store makes during a network partition, between consistency and availability.

Listed in Architecture principles, after Total-Order Broadcast and before PACELC Theorem.

Requires

• Network Partition Possibility

Reinforces

• Causal Consistency
• Eventual Consistency

Enables

• Explicit Consistency/Availability Choice Under Partition

Conflicts with

• Assumed Total Consistency And Availability

In tension with

• Latency

Tensions

• CAP Theorem / Latency

Violated by

• Assumed Total Consistency And Availability

Severity

• contextual

Category

• Causality / Ordering / Distributed Time

Required by

• PACELC Theorem

Reinforced by

• PACELC Theorem

Linked from

• Separate, trade, or mitigate
• Causality / Ordering / Distributed Time
• Event / Messaging / Asynchronous Architecture
• Scalability / Performance / Optimization
• Causality / Ordering / Distributed Time
• Severity levels
• The resolutions