What is CAP？

Content

There are many background introductions about the CAP theory, but here is not much introduction, let's talk about how to understand it.

Explain the three nouns in easy-to-understand terms:

consistency

If you have just written to one node, then later, the data read from another node must be the data just written, not older data.

Availability

If a node is requested, the node must be able to respond. If the node goes down, there is no question of availability.

Partition tolerance

Whether to tolerate network partitions, that is, nodes can be allowed to communicate with other nodes.

CAP means that we can only guarantee that at most two of the conditions are true at the same time.