CAP Theorem
The CAP theorem is a fundamental principle in distributed systems theory that defines the trade-offs between three important properties: Consistency, Availability, and Partition tolerance. The theorem, introduced by Eric Brewer in 2000, asserts that it is impossible for a distributed system to simultaneously guarantee all three properties. Instead, a distributed system can provide at most two of these three guarantees. The concept has significant implications for the design of distributed databases and applications, as systems must choose which two properties to prioritize based on the specific needs of the use case.
https://en.wikipedia.org/wiki/CAP_theorem
In the context of the CAP theorem, consistency refers to the guarantee that every read operation will return the most recent write, ensuring that all nodes in the system have the same data at any given time. Availability means that every request (read or write) will receive a response, even if some nodes are unavailable. Partition tolerance means that the system will continue to operate even if network partitions or communication breakdowns occur between different parts of the system. Depending on which two of these three properties a system prioritizes, different consistency models like Eventual consistency or Strong consistency are used.
https://en.wikipedia.org/wiki/Consistency_(distributed_databases)
The CAP theorem helps developers and engineers make informed decisions about trade-offs in system architecture. For example, a system prioritizing consistency and partition tolerance, like HBase or Cassandra, may sacrifice availability in the event of a partition, ensuring that only the most up-to-date data is available. In contrast, systems prioritizing availability and partition tolerance, like CouchDB, might sacrifice consistency for the sake of responsiveness and uptime. Understanding the CAP theorem is essential for designing distributed systems that meet specific performance and reliability needs.
https://en.wikipedia.org/wiki/Distributed_database
CAP theorem