Unverified50% confidenceConceptExact time
In distributed systems, at-least-once delivery semantics means the sender guarantees the event is delivered at least once, but does not guarantee it is delivered only once.
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10/14/2026
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Related Claims
Unverified"Exactly-once" is a distributed systems semantic guarantee: even if a message is sent multiple times, the receiver will process it only once.80% similarUnverifiedThe one-time nonce (Number Used Once) mechanism attaches a random string to each authorization credential; after the server consumes it, the nonce is marked as used, and any subsequent request with the same nonce is rejected outright.66% similarUnverifiedIdempotency keys are a common means in distributed systems of preventing the same operation from being executed multiple times: the caller carries a globally unique identifier when initiating a request, the server deduplicates on that identifier, and on encountering a duplicate request with the same key it directly returns the first result without re-executing the side effects.66% similarUnverified即使消息显示送达，也不代表接收端一定会执行消息中的指令65% similarUnverifiedFor customer emails (receipts, status updates), at-least-once with deduplication hints is the correct trade-off, because missing a send is worse than a duplicate.64% similar
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