{"id":"delivery-guarantees-follow-write-read-cost-asymmetry","text":"Message delivery guarantees enforced at the consumer side instantiate the architecture's broader read-path responsibility pattern: just as KV reads absorb convergence (repair) and computation (lazy evaluation), message consumers absorb delivery semantics (at-least-once vs exactly-once) through their own poll/commit behavior, keeping the write/publish path simple and coordination-free.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["message-delivery-guarantees-are-consumer-side","reads-are-active-convergence-engines"],"outlist":[],"label":"Consumer-side delivery guarantees are a specific case of read-path absorbing complexity"}],"dependents":["read-path-is-universal-site-of-deferred-work"],"metadata":{"last_reviewed":"2026-06-06T06:26:57","review_result":"pass"},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"delivery-guarantees-follow-write-read-cost-asymmetry","truth_value":"IN","reason":"SL justification valid","antecedents":["message-delivery-guarantees-are-consumer-side","reads-are-active-convergence-engines"],"label":"Consumer-side delivery guarantees are a specific case of read-path absorbing complexity"},{"node":"message-delivery-guarantees-are-consumer-side","truth_value":"IN","reason":"SL justification valid","antecedents":["dmq-delivery-semantics-in-poll","dmq-two-tier-offset-tracking"],"label":"The two-tier offset gap (current minus committed) is the mechanism that enables all three delivery modes — the broker just stores offsets, consumers choose semantics"},{"node":"dmq-delivery-semantics-in-poll","truth_value":"IN","reason":"premise"},{"node":"dmq-two-tier-offset-tracking","truth_value":"IN","reason":"premise"},{"node":"reads-are-active-convergence-engines","truth_value":"IN","reason":"SL justification valid","antecedents":["reads-are-not-pure-across-domains","read-path-absorbs-consistency-and-computation-cost"],"label":"Reads both compute deferred results and mutate state — they are the system's active convergence mechanism"},{"node":"reads-are-not-pure-across-domains","truth_value":"IN","reason":"SL justification valid","antecedents":["kv-read-repair-on-get","email-service-get-email-marks-read"],"label":"Two independent domains (distributed KV, email) both attach mandatory side effects to read operations, showing that reads-with-side-effects is a cross-cutting pattern rather than a domain-specific quirk"},{"node":"kv-read-repair-on-get","truth_value":"IN","reason":"premise"},{"node":"email-service-get-email-marks-read","truth_value":"IN","reason":"premise"},{"node":"read-path-absorbs-consistency-and-computation-cost","truth_value":"IN","reason":"SL justification valid","antecedents":["lazy-read-time-evaluation-trades-write-simplicity-for-read-cost","kv-read-path-is-self-healing"],"label":"lazy eval (autocomplete decay, URL expiration, payment balance) defers computation to reads; KV read repair defers convergence to reads — the combined pattern reveals a systematic bias toward read-path complexity across the repo"},{"node":"lazy-read-time-evaluation-trades-write-simplicity-for-read-cost","truth_value":"IN","reason":"SL justification valid","antecedents":["autocomplete-decay-is-read-time","url-shortener-expiration-lazy","payment-balance-never-cached"],"label":"Three independent systems chose lazy evaluation, suggesting write-simplicity is the dominant concern in pedagogical implementations"},{"node":"autocomplete-decay-is-read-time","truth_value":"IN","reason":"premise"},{"node":"url-shortener-expiration-lazy","truth_value":"IN","reason":"premise"},{"node":"payment-balance-never-cached","truth_value":"IN","reason":"premise"},{"node":"kv-read-path-is-self-healing","truth_value":"IN","reason":"SL justification valid","antecedents":["kv-read-repair-on-get","kv-node-stores-sibling-versions"],"label":"Read repair + sibling detection make the read path an active consistency mechanism, not just a query"},{"node":"kv-node-stores-sibling-versions","truth_value":"IN","reason":"premise"}]}}