Systems
CAP theorem
Brewer's theorem says you can have at most two of consistency, availability, and partition tolerance. In practice, the real choice is between C and A under failure.
#distributed-systems
3 notes Systems
Paxos
The original consensus algorithm. Two phases — prepare and accept — reach agreement on a single value among unreliable processes. Notoriously hard to teach.
Systems
Raft
A consensus algorithm designed to be understandable. Decomposes the problem into leader election, log replication, and safety — with terms and majority voting.