Distributed Systems Theory

What CAP says and how it gets misquoted, PACELC, and fail-stop vs Byzantine faults.

Linearizability, sequential consistency, causal consistency, eventual consistency, and the session guarantees: read-your-writes, monotonic reads, monotonic writes.

R + W > N, sloppy quorums, hinted handoff, read repair, anti-entropy, and leaderless replication.

Raft terms, logs, and elections, Paxos, split brain, fencing tokens, and ZooKeeper and etcd.

NTP skew, monotonic vs wall clocks, Lamport and vector clocks, hybrid logical clocks, and TrueTime.

Two- and three-phase commit, sagas, the transactional outbox, and choreography vs orchestration.

At-most-once, at-least-once, and effectively-once delivery, idempotency keys, and dedup windows.

CRDTs such as G-counters and OR-sets, operational transform, and gossip protocols.