Internet Engineering Task Force (IETF)                  R. Fielding, Ed.
Request for Comments: 7231                                         Adobe
Obsoletes: 2616                                          J. Reschke, Ed.
Updates: 2817                                                 greenbytes
Category: Standards Track                                      June 2014
ISSN: 2070-1721


        Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

Abstract

    The Hypertext Transfer Protocol (HTTP) is a stateless application-
    level protocol for distributed, collaborative, hypertext information
    systems.  This document defines the semantics of HTTP/1.1 messages,
    as expressed by request methods, request header fields, response
    status codes, and response header fields, along with the payload of
    messages (metadata and body content) and mechanisms for content
    negotiation.

 
RFC 7231             HTTP/1.1 Semantics and Content            June 2014


6.6.3.  502 Bad Gateway

    The 502 (Bad Gateway) status code indicates that the server, while
    acting as a gateway or proxy, received an invalid response from an
    inbound server it accessed while attempting to fulfill the request.




Fielding & Reschke           Standards Track                   [Page 63]