Changeset 493


Ignore:
Timestamp:
Mar 3, 2009, 10:21:25 PM (11 years ago)
Author:
mnot@…
Message:

tweak freshness intro

File:
1 edited

Legend:

Unmodified
Added
Removed
  • draft-ietf-httpbis/latest-roy/p6-cache.xml

    r492 r493  
    473473        <t>When a response is "fresh" in the cache, it can be used to satisfy subsequent
    474474          requests without contacting the origin server, thereby improving efficiency.</t>
    475         <t>The primary mechanism for avoiding requests is for an origin server to provide an
     475        <t>The primary mechanism for determining freshness is for an origin server to provide an
    476476          explicit expiration time in the future, using either the Expires header (<xref
    477477            target="header.expires" />) or the max-age response cache directive (<xref
     
    483483          stale, so that caches should validate it before using it for subsequent requests. <cref>This wording may cause confusion, because the response may still be served stale.</cref></t>
    484484        <t>Since origin servers do not always provide explicit expiration times, HTTP caches may
    485           assign heuristic expiration times when they are not specified, employing algorithms that
     485          also assign heuristic expiration times when they are not specified, employing algorithms that
    486486          use other header values (such as the Last-Modified time) to estimate a plausible
    487487          expiration time. The HTTP/1.1 specification does not provide specific algorithms, but does
    488488          impose worst-case constraints on their results.</t>
    489         <t>The calculation to determine if a response has expired is:</t>
     489        <t>The calculation to determine if a response is fresh is:</t>
    490490        <figure>
    491491          <artwork type="code">
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