CAP theorem
ID: 23e10c0c-33a4-49c9-9518-e3de14702a30 ROAM_REFS: @gilbertBrewersConjectureFeasibility2002 MTIME: [2025-01-26 Sun 21:14]
"consistency, availability, partition tolerance - pick any two". An asynchronous network can provide only two of the three guarantees:
- Consistency - maintaining a common state among nodes under all observations
- Availability - the state as a whole always being observable
Network partition tolerance - if the network gets partitioned, some guarantee is upheld (call this "service"). In practice, which?
This last question prompts us to look at the PACELC theorem, a later extension. From Wikipedia:
n database theory, the PACELC theorem is an extension to the CAP theorem. It states that in case of network partitioning (P) in a distributed computer system, one has to choose between availability (A) and consistency (C) (as per the CAP theorem), but else (E), even when the system is running normally in the absence of partitions, one has to choose between latency (L) and loss of consistency (C).
A discretization of relativity.