Hypertext Transfer Protocol (HTTP): Caching
draft-fielding-httpbis-http-cache-00

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00

Network Working Group                                   R. Fielding, Ed.
Internet-Draft                                                     Adobe
Obsoletes: 7234 (if approved)                         M. Nottingham, Ed.
Intended status: Standards Track                                  Fastly
Expires: September 6, 2018                               J. Reschke, Ed.
                                                              greenbytes
                                                           March 5, 2018

              Hypertext Transfer Protocol (HTTP): Caching
                  draft-fielding-httpbis-http-cache-00

Abstract

   The Hypertext Transfer Protocol (HTTP) is a stateless application-
   level protocol for distributed, collaborative, hypertext information
   systems.  This document defines HTTP caches and the associated header
   fields that control cache behavior or indicate cacheable response
   messages.

   This document obsoletes RFC 7234.

Editorial Note

   This note is to be removed before publishing as an RFC.

   _This is a temporary document for the purpose of planning the
   revisions of RFCs 7230 to 7235.  This is not yet an official work
   item of the HTTP Working Group._

   Discussion of this draft takes place on the HTTP working group
   mailing list (ietf-http-wg@w3.org), which is archived at
   <http://lists.w3.org/Archives/Public/ietf-http-wg/>.

   Errata for RFC 7234 have been collected at <https://www.rfc-
   editor.org/errata_search.php?rfc=7234>, and an additional issues list
   lives at <https://github.com/httpwg/http11bis/issues>.

   The changes in this draft are summarized in Appendix D.1.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute

Fielding, et al.        Expires September 6, 2018               [Page 1]
Internet-Draft                HTTP Caching                    March 2018

   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 6, 2018.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Conformance and Error Handling  . . . . . . . . . . . . .   4
     1.2.  Syntax Notation . . . . . . . . . . . . . . . . . . . . .   5
       1.2.1.  Delta Seconds . . . . . . . . . . . . . . . . . . . .   5
   2.  Overview of Cache Operation . . . . . . . . . . . . . . . . .   5
   3.  Storing Responses in Caches . . . . . . . . . . . . . . . . .   6
     3.1.  Storing Incomplete Responses  . . . . . . . . . . . . . .   7
     3.2.  Storing Responses to Authenticated Requests . . . . . . .   7
     3.3.  Combining Partial Content . . . . . . . . . . . . . . . .   8

Fielding, et al.        Expires September 6, 2018               [Page 2]
Internet-Draft                HTTP Caching                    March 2018

   4.  Constructing Responses from Caches  . . . . . . . . . . . . .   8
     4.1.  Calculating Secondary Keys with Vary  . . . . . . . . . .  10
     4.2.  Freshness . . . . . . . . . . . . . . . . . . . . . . . .  11