CAP Theorem
States that a distributed system can guarantee at most two of: Consistency, Availability, and Partition Tolerance.
Also: Brewer's theorem
Definition
The CAP theorem, formulated by Eric Brewer, states that a distributed data store can provide at most two out of three guarantees: Consistency (every read receives the most recent write), Availability (every request receives a non-error response, though not necessarily the most recent data), and Partition Tolerance (the system continues operating despite network partitions). In practice, partition tolerance is mandatory in distributed networks, so the real trade-off is between consistency and availability.
Example
“DynamoDB (AP) remains available during a network partition but may return stale data; HBase (CP) maintains consistency but may reject requests during partition events.”
Synonyms
- distributed system trade-offs
- Brewer theorem
Images
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Related Terms
- acid
- distributed-database
- consistency
- availability