CAP theorem

The CAP theorem, also known as Brewer’s theorem, is a fundamental principle in distributed systems. It states that a distributed system cannot simultaneously provide consistency, availability, and partition tolerance all at once. The acronym CAP represents the three properties.

In distributed systems, network partitions are an inevitable occurrence due to various reasons, such as hardware failures, network outages, or even routine maintenance. These partitions lead to nodes being split into isolated groups, disrupting the normal flow of communication. Consequently, the system faces a crucial decision in the face of such partitions: prioritizing between consistency and availability. On one hand, if a system opts for availability and partition tolerance (AP), it continues to function despite the partition but may sacrifice consistency, meaning all nodes might not have the same data at the same time. On the other hand, prioritizing consistency and partition tolerance...