Ch8 Sol3b: consumer states, dedup horizon, recovery

Ch8 Sol3b: consumer states, dedup horizon, recovery A lifecycle diagram generated by Archify. Message handling Redelivery Dedup + horizon Terminal exits Delivered · broker hands over · Message handling · at-least-once 01 Delivered broker hands over at-least-once Processing · transaction open · Message handling · key + effect 02 Processing transaction open key + effect Committed · key + effect durable · Message handling · durable 03 Committed key + effect durable durable Acked · broker may still redeliver · Message handling · not a delete 04 Acked broker may still redeliver not a delete Redelivered · crash 1, 2 or 3 · Redelivery · re-enter Redelivered crash 1, 2 or 3 re-enter Key live · skip effect, ACK · Dedup + horizon · UNIQUE guard Key live skip effect, ACK UNIQUE guard Key expired · past 30d horizon · Dedup + horizon · gone Key expired past 30d horizon gone Poison discarded · payload mismatch · Terminal exits · terminal Poison discarded payload mismatch terminal Effect duplicated · no dedup, or past horizon · Terminal exits · terminal Effect duplicated no dedup, or past horizon terminal Applied once · exactly-once inside horizon · Terminal exits · terminal Applied once exactly-once inside horizon terminal atomic key + effect payload mismatch crash 1 effect applied once ACK after commit crash 2 crash 3 key unknown: apply key known: skip safe ACK past 30d horizon 6-month replay re-applies Legend initial state active waiting success failure / exit final state