PACELC.
also: PACELC theoremCAP extended: if partitioned, choose availability or consistency; else, even with no partition, choose latency or consistency.
the two-minute refresher
- P → A or C (that is CAP); E (else) → L or C.
- Keeping replicas in sync costs round trips even when the network is healthy.
- DynamoDB and Cassandra are PA/EL (fast and available, eventually consistent); HBase is PC/EC.