Coordination
6 pages
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Broadcast Protocols
concept
best-effort, reliable (eager/gossip), total order broadcast; consensus requirement; relationship to CRDTs and replication
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Consensus Algorithms
concept
Raft, Paxos, Zab; FLP result; ZooKeeper/etcd; equivalence theorem (linearizable CAS = total order broadcast = locks = uniqueness)
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Distributed Transactions
concept
ACID, 2PL, OCC, MVCC, 2PC, Spanner, Saga, Outbox; XA limitations; coordination-avoiding correctness; Newman's "just say no" to 2PC during migration
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Leader Election
concept
Raft state machine (follower/candidate/leader); election terms; CAS+lease practical approach; fencing tokens for mutual exclusion; leader as SPOF
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Orchestration vs Choreography
comparison
Decision guide: when to use a central coordinator vs event-driven choreography; team-ownership heuristic; God Orchestrator anti-pattern; workflow state management options
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Saga Pattern
pattern
Distributed transactions via local transactions + compensations; 8 saga type taxonomy; semantic vs implementation coupling; orchestration/choreography trade-offs; DDD: saga vs process manager distinction; stateless/stateful saga; process manager as aggregate; Newman: backward/forward recovery, semantic rollbacks, step reordering, team-based coordination choice