After 28 Years, HTTP Still Can’t Agree on What ‘Upstream’ Means
After 28 years, HTTP still can’t agree on what ‘upstream’ and ‘downstream’ mean. The terms are perspective-dependent — clients and servers see opposite directions as upstream. Implementations like Envoy embed conflicting interpretations, and no clean fix exists without breaking running systems. This isn’t just semantics; it’s the kind of ambiguity that silently causes bugs at 3 AM.