CAP theorem states that it’s impossible for a distributed computer system to have all the following simultaneously
All part of the systems see the same data.
A guarantee that each request receives a response regardless of success / failure.
- Partition tolerance
The whole system continue to work despite disconnection, message loss or any failure in the subsystems.
Eric Brewer said that a distributed computer system can only have 2 out of these 3 functions at a time.