Aug 22, 2011, 12:53:05 AM (8 years ago)

Clarify one-year limit on Expires; addresses #290

1 edited


  • draft-ietf-httpbis/latest/p6-cache.html

    r1396 r1400  
    362362  }
    363363  @bottom-center {
    364        content: "Expires February 10, 2012";
     364       content: "Expires February 23, 2012";
    365365  }
    366366  @bottom-right {
    408408      <meta name="dct.creator" content="Reschke, J. F.">
    409409      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p6-cache-latest">
    410       <meta name="dct.issued" scheme="ISO8601" content="2011-08-09">
     410      <meta name="dct.issued" scheme="ISO8601" content="2011-08-22">
    411411      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
    412412      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 6 of the seven-part specification that defines the protocol referred to as &#34;HTTP/1.1&#34; and, taken together, obsoletes RFC 2616. Part 6 defines requirements on HTTP caches and the associated header fields that control cache behavior or indicate cacheable response messages.">
    434434            </tr>
    435435            <tr>
    436                <td class="left">Expires: February 10, 2012</td>
     436               <td class="left">Expires: February 23, 2012</td>
    437437               <td class="right">J. Mogul</td>
    438438            </tr>
    495495            <tr>
    496496               <td class="left"></td>
    497                <td class="right">August 9, 2011</td>
     497               <td class="right">August 22, 2011</td>
    498498            </tr>
    499499         </tbody>
    525525         in progress”.
    526526      </p>
    527       <p>This Internet-Draft will expire on February 10, 2012.</p>
     527      <p>This Internet-Draft will expire on February 23, 2012.</p>
    528528      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
    529529      <p>Copyright © 2011 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
    13591359</pre><div id="rfc.figure.u.14"></div>
    13601360      <p>For example</p>  <pre class="text">  Expires: Thu, 01 Dec 1994 16:00:00 GMT
    1361 </pre><div class="note" id="rfc.section.3.3.p.6">
     1361</pre><p id="rfc.section.3.3.p.6">A cache <em class="bcp14">MUST</em> treat other invalid date formats, especially including the value "0", as in the past (i.e., "already expired").
     1362      </p>
     1363      <div class="note" id="rfc.section.3.3.p.7">
    13621364         <p> <b>Note:</b> If a response includes a Cache-Control field with the max-age directive (see <a href="#cache-response-directive" title="Response Cache-Control Directives">Section&nbsp;3.2.2</a>), that directive overrides the Expires field. Likewise, the s-maxage directive overrides Expires in shared caches.
    13631365         </p>
    13641366      </div>
    1365       <p id="rfc.section.3.3.p.7">A server <em class="bcp14">SHOULD NOT</em> send Expires dates more than one year in the future.
    1366       </p>
    1367       <p id="rfc.section.3.3.p.8">A cache <em class="bcp14">MUST</em> treat other invalid date formats, especially including the value "0", as in the past (i.e., "already expired").
     1367      <p id="rfc.section.3.3.p.8">Historically, HTTP required the Expires field-value to be no more than a year in the future. While longer freshness lifetimes
     1368         are no longer prohibited, extremely large values have been demonstrated to cause problems (e.g., clock overflows due to use
     1369         of 32-bit integers for time values), and most caches will evict a response far sooner than that. Therefore, senders ought
     1370         not produce them.
    13681371      </p>
    13691372      <div id="rfc.iref.p.5"></div>
    20412044      </ul>
    20422045      <h2 id="rfc.section.C.17"><a href="#rfc.section.C.17">C.17</a>&nbsp;<a id="changes.since.15" href="#changes.since.15">Since draft-ietf-httpbis-p6-cache-15</a></h2>
    2043       <p id="rfc.section.C.17.p.1">None yet.</p>
     2046      <p id="rfc.section.C.17.p.1">Closed issues: </p>
     2047      <ul>
     2048         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/290">http://tools.ietf.org/wg/httpbis/trac/ticket/290</a>&gt;: "Motivate one-year limit for Expires"
     2049         </li>
     2050      </ul>
    20442051      <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>
    20452052      <p class="noprint"><a href="#rfc.index.A">A</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.E">E</a> <a href="#rfc.index.F">F</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.H">H</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.N">N</a> <a href="#rfc.index.O">O</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> <a href="#rfc.index.S">S</a> <a href="#rfc.index.V">V</a> <a href="#rfc.index.W">W</a>
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