Coordination¶
Covers Atomic Commit 2PC 3PC TCC, Coordination Services, Exactly Once Semantics, Gossip Protocol, Idempotency Keys, Leader Election, Leases and Fencing, Optimistic vs Pessimistic Locking, Paxos, and Raft.
Topics¶
| Topic | What it covers |
|---|---|
| Atomic Commit 2PC 3PC TCC | Three progressively more sophisticated attempts to make "all these databases commit together, or none of them do" work across a network —… |
| Coordination Services | A small, purpose-built, highly-consistent cluster (etcd, ZooKeeper, Consul) that the rest of your distributed system leans on for the… |
| Exactly Once Semantics | "Exactly-once" is one of the most misused phrases in distributed systems. True exactly-once delivery across a network is provably… |
| Gossip Protocol | Instead of a central authority tracking cluster membership, every node periodically exchanges what it knows with a few random peers — and… |
| Idempotency Keys | A unique identifier attached to a logical operation so that retrying it — deliberately or by accident, once or a thousand times — produces… |
| Leader Election | Make exactly one node in a cluster do the singleton job — and never let two nodes believe they're in charge at the same time. This is the… |
| Leases and Fencing | A lease is a time-bounded right to do something — hold a lock, act as leader — that expires automatically if not renewed. A fencing token… |
| Optimistic vs Pessimistic Locking | The same read-and-write concurrency choice covered for a single database in the Locking & Concurrency Control topic, now applied across… |
| Paxos | The original proof that a group of unreliable nodes can agree on a single value even if some fail — the theoretical foundation almost every… |
| Raft | Consensus, designed to be understood. Raft decomposes the problem into leader election, log replication, and safety — each explained and… |