mod_cache.html.en

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    authorization will <em>never</em> be cached.</p>

    <div class="example"><p><code>
      CacheIgnoreCacheControl On
    </code></p></div>

    <div class="warning"><h3>Warning:</h3>
       This directive will allow serving from the cache even if the client has
       requested that the document not be served from the cache.  This might
       result in stale content being served.
    </div>

<h3>See also</h3>
<ul>
<li><code class="directive"><a href="#cachestoreprivate">CacheStorePrivate</a></code></li>
<li><code class="directive"><a href="#cachestorenostore">CacheStoreNoStore</a></code></li>
</ul>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheIgnoreHeaders" id="CacheIgnoreHeaders">CacheIgnoreHeaders</a> <a name="cacheignoreheaders" id="cacheignoreheaders">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Do not store the given HTTP header(s) in the cache.
</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheIgnoreHeaders <var>header-string</var> [<var>header-string</var>] ...</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheIgnoreHeaders None</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>According to RFC 2616, hop-by-hop HTTP headers are not stored in
    the cache.  The following HTTP headers are hop-by-hop headers and thus
    do not get stored in the cache in <em>any</em> case regardless of the
    setting of <code class="directive">CacheIgnoreHeaders</code>:</p>

    <ul>
      <li><code>Connection</code></li>
      <li><code>Keep-Alive</code></li>
      <li><code>Proxy-Authenticate</code></li>
      <li><code>Proxy-Authorization</code></li>
      <li><code>TE</code></li>
      <li><code>Trailers</code></li>
      <li><code>Transfer-Encoding</code></li>
      <li><code>Upgrade</code></li>
    </ul>

    <p><code class="directive">CacheIgnoreHeaders</code> specifies additional HTTP
    headers that should not to be stored in the cache.  For example, it makes
    sense in some cases to prevent cookies from being stored in the cache.</p>

    <p><code class="directive">CacheIgnoreHeaders</code> takes a space separated list
    of HTTP headers that should not be stored in the cache. If only hop-by-hop
    headers not should be stored in the cache (the RFC 2616 compliant
    behaviour), <code class="directive">CacheIgnoreHeaders</code> can be set to
    <code>None</code>.</p>

    <div class="example"><h3>Example 1</h3><p><code>
      CacheIgnoreHeaders Set-Cookie
    </code></p></div>

    <div class="example"><h3>Example 2</h3><p><code>
      CacheIgnoreHeaders None
    </code></p></div>

    <div class="warning"><h3>Warning:</h3>
      If headers like <code>Expires</code> which are needed for proper cache
      management are not stored due to a
      <code class="directive">CacheIgnoreHeaders</code> setting, the behaviour of
      mod_cache is undefined.
    </div>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheIgnoreNoLastMod" id="CacheIgnoreNoLastMod">CacheIgnoreNoLastMod</a> <a name="cacheignorenolastmod" id="cacheignorenolastmod">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ignore the fact that a response has no Last Modified
header.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheIgnoreNoLastMod On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheIgnoreNoLastMod Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>Ordinarily, documents without a last-modified date are not cached.
    Under some circumstances the last-modified date is removed (during
    <code class="module"><a href="../mod/mod_include.html">mod_include</a></code> processing for example) or not provided
    at all. The <code class="directive">CacheIgnoreNoLastMod</code> directive
    provides a way to specify that documents without last-modified dates
    should be considered for caching, even without a last-modified date.
    If neither a last-modified date nor an expiry date are provided with
    the document then the value specified by the
    <code class="directive">CacheDefaultExpire</code> directive will be used to
    generate an expiration date.</p>

    <div class="example"><p><code>
      CacheIgnoreNoLastMod On
    </code></p></div>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheLastModifiedFactor" id="CacheLastModifiedFactor">CacheLastModifiedFactor</a> <a name="cachelastmodifiedfactor" id="cachelastmodifiedfactor">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The factor used to compute an expiry date based on the
LastModified date.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheLastModifiedFactor <var>float</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheLastModifiedFactor 0.1</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>In the event that a document does not provide an expiry date but does
    provide a last-modified date, an expiry date can be calculated based on
    the time since the document was last modified. The
    <code class="directive">CacheLastModifiedFactor</code> directive specifies a
    <var>factor</var> to be used in the generation of this expiry date
    according to the following formula:

    <code>expiry-period = time-since-last-modified-date * <var>factor</var>
    expiry-date = current-date + expiry-period</code>

    For example, if the document was last modified 10 hours ago, and
    <var>factor</var> is 0.1 then the expiry-period will be set to
    10*0.1 = 1 hour. If the current time was 3:00pm then the computed
    expiry-date would be 3:00pm + 1hour = 4:00pm.

    If the expiry-period would be longer than that set by
    <code class="directive">CacheMaxExpire</code>, then the latter takes
    precedence.</p>

    <div class="example"><p><code>
      CacheLastModifiedFactor 0.5
    </code></p></div>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheMaxExpire" id="CacheMaxExpire">CacheMaxExpire</a> <a name="cachemaxexpire" id="cachemaxexpire">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The maximum time in seconds to cache a document</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheMaxExpire <var>seconds</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheMaxExpire 86400 (one day)</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>The <code class="directive">CacheMaxExpire</code> directive specifies the maximum number of
    seconds for which cachable HTTP documents will be retained without checking the origin
    server. Thus, documents will be out of date at most this number of seconds. This maximum
    value is enforced even if an expiry date was supplied with the document.</p>

    <div class="example"><p><code>
      CacheMaxExpire 604800
    </code></p></div>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheStoreNoStore" id="CacheStoreNoStore">CacheStoreNoStore</a> <a name="cachestorenostore" id="cachestorenostore">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Attempt to cache requests or responses that have been marked as no-store.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheStoreNoStore On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheStoreNoStore Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>Ordinarily, requests or responses with Cache-Control: no-store header
       values will not be stored in the cache.  The
       <code class="directive">CacheStoreNoCache</code> directive allows this
       behavior to be overridden.  <code class="directive">CacheStoreNoCache</code> On
       tells the server to attempt to cache the resource even if it contains
       no-store header values.  Resources requiring authorization will
       <em>never</em> be cached.</p>

    <div class="example"><p><code>
      CacheStoreNoStore On
    </code></p></div>

    <div class="warning"><h3>Warning:</h3>
       As described in RFC 2616, the no-store directive is intended to
       "prevent the inadvertent release or retention of sensitive information
       (for example, on backup tapes)."  Enabling this option could store
       sensitive information in the cache.  You are hereby warned.
    </div>

<h3>See also</h3>
<ul>
<li><code class="directive"><a href="#cacheignorecachecontrol">CacheIgnoreCacheControl</a></code></li>
<li><code class="directive"><a href="#cachestoreprivate">CacheStorePrivate</a></code></li>
</ul>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="CacheStorePrivate" id="CacheStorePrivate">CacheStorePrivate</a> <a name="cachestoreprivate" id="cachestoreprivate">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Attempt to cache responses that the server has marked as private</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheStorePrivate On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheStorePrivate Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr>
</table>
    <p>Ordinarily, responses with Cache-Control: private header values will not
       be stored in the cache.  The <code class="directive">CacheStorePrivate</code>
       directive allows this behavior to be overridden.
       <code class="directive">CacheStorePrivate</code> On
       tells the server to attempt to cache the resource even if it contains
       private header values.  Resources requiring authorization will
       <em>never</em> be cached.</p>

    <div class="example"><p><code>
      CacheStorePrivate On
    </code></p></div>

    <div class="warning"><h3>Warning:</h3>
       This directive will allow caching even if the upstream server has
       requested that the resource not be cached.  This directive is only
       ideal for a 'private' cache.
    </div>

<h3>See also</h3>
<ul>
<li><code class="directive"><a href="#cacheignorecachecontrol">CacheIgnoreCacheControl</a></code></li>
<li><code class="directive"><a href="#cachestorenostore">CacheStoreNoStore</a></code></li>
</ul>
</div>
</div>
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