hesela.devFLP impossibility
FLP impossibility rules out guaranteed termination of deterministic consensus in a fully asynchronous message-passing system that must tolerate one process crash.
The model has reliable messages but no timing bounds or perfect crash detector. Admissible runs allow at most one stopped process and eventually deliver messages to nonfaulty processes. [1]
Every protocol satisfying agreement and nontriviality has some admissible run that never decides. This does not mean every execution stalls, and an actual crash or permanent partition is not required. [1]
The theorem separates agreement from guaranteed termination; it gives no outage probability or latency estimate. [1]
Relations
- related
- Partial synchrony, Failure detector, Raft, Paxos
Citations
Sources & caveats
- Primary-source synthesis of the 1985 journal paper, sections 1-3. The conference presentation was in 1983. No new proof, protocol execution or empirical result is claimed.