# Glossary of Distributed Systems Terms The following links are placeholders for further research and learning. | Term | Short Definition | Link | |------|------------------|------| | CAP Theorem | Tradeoff between Consistency, Availability, and Partition Tolerance | [[CAP Theorem]] | | Consensus | Agreement among distributed nodes on a single value or sequence | [[Consensus Algorithms]] | | Paxos | A family of protocols for consensus under crash failure | [[Paxos]] | | Raft | Readable consensus algorithm used in many systems | [[Raft]] | | Quorum | Minimum number of nodes agreeing for a decision | [[Quorums]] | | Vector Clock | Data structure tracking causality among events | [[Vector Clocks]] | | Gossip Protocol | Peer-to-peer state dissemination protocol | [[Gossip Protocols]] | | 2PC | Protocol for distributed transactions with a coordinator | [[Two-Phase Commit (2PC)]] | | 3PC | Non-blocking extension of 2PC | [[Three-Phase Commit (3PC)]] | | Saga | Pattern for breaking long transactions into local + compensating actions | [[Saga Pattern]] | | Leader Election | Protocol to dynamically choose a coordinator | [[Leader Election]] | | Eventual Consistency | Guarantees all replicas converge eventually | [[Eventual Consistency]] | | State Machine Replication | Replicating deterministic services across nodes | [[State Machine Replication]] | | Partial Failure | Some components fail while others operate correctly | [[Partial Failure]] | | Split-Brain | Cluster splits and both sides believe they’re the leader | [[Split-Brain Scenarios]] | | Network Partition | Loss of communication between parts of the system | [[Network Partition]] | | Fault Tolerance | System continues to operate under failure | [[Fault Tolerance]] | | Distributed Lock | Mechanism to ensure exclusive access to resources | [[Distributed Locking]] | | Heartbeat | Periodic message used to detect node liveness | [[Failure Detectors]] | | Idempotency | Operation can be repeated safely | [[Idempotency]] |