mirror of
				https://github.com/apache/httpd.git
				synced 2025-11-03 17:53:20 +03:00 
			
		
		
		
	git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@732126 13f79535-47bb-0310-9956-ffa450edef68
		
			
				
	
	
		
			491 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
			
		
		
	
	
			491 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
<?xml version="1.0" encoding="ISO-8859-1"?>
 | 
						||
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 | 
						||
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
 | 
						||
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 | 
						||
              This file is generated from xml source: DO NOT EDIT
 | 
						||
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 | 
						||
      -->
 | 
						||
<title>mod_cache - Apache HTTP Server</title>
 | 
						||
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
 | 
						||
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
 | 
						||
<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
 | 
						||
<link href="../images/favicon.ico" rel="shortcut icon" /></head>
 | 
						||
<body>
 | 
						||
<div id="page-header">
 | 
						||
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
 | 
						||
<p class="apache">Apache HTTP Server Version 2.3</p>
 | 
						||
<img alt="" src="../images/feather.gif" /></div>
 | 
						||
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
 | 
						||
<div id="path">
 | 
						||
<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.3</a> > <a href="./">Modules</a></div>
 | 
						||
<div id="page-content">
 | 
						||
<div id="preamble"><h1>Apache Module mod_cache</h1>
 | 
						||
<div class="toplang">
 | 
						||
<p><span>Available Languages: </span><a href="../en/mod/mod_cache.html" title="English"> en </a> |
 | 
						||
<a href="../ja/mod/mod_cache.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
 | 
						||
<a href="../ko/mod/mod_cache.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p>
 | 
						||
</div>
 | 
						||
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Content cache keyed to URIs.</td></tr>
 | 
						||
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
 | 
						||
<tr><th><a href="module-dict.html#ModuleIdentifier">Module<EFBFBD>Identifier:</a></th><td>cache_module</td></tr>
 | 
						||
<tr><th><a href="module-dict.html#SourceFile">Source<EFBFBD>File:</a></th><td>mod_cache.c</td></tr></table>
 | 
						||
<h3>Summary</h3>
 | 
						||
 | 
						||
    <div class="warning">This module should be used with care and
 | 
						||
    can be used to circumvent <code class="directive"><a href="../mod/mod_authz_host.html#allow">Allow</a></code> and <code class="directive"><a href="../mod/mod_authz_host.html#deny">Deny</a></code> directives. You 
 | 
						||
    should not enable caching for any content to which you wish
 | 
						||
    to limit access by client host name, address or environment
 | 
						||
    variable.</div>  
 | 
						||
 | 
						||
    <p><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> implements an <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> compliant HTTP
 | 
						||
    content cache that can be used to cache either local or proxied content.
 | 
						||
    <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> requires the services of one or more storage
 | 
						||
    management modules. One storage management module is included in
 | 
						||
    the base Apache distribution:</p>
 | 
						||
    <dl>
 | 
						||
    <dt><code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code></dt>
 | 
						||
    <dd>implements a disk based storage manager.</dd>
 | 
						||
    </dl>
 | 
						||
 | 
						||
    <p>Content is stored in and retrieved from the cache using URI based keys. Content with
 | 
						||
    access protection is not cached.</p>
 | 
						||
    <p>Further details, discussion, and examples, are provided in the
 | 
						||
    <a href="../caching.html">Caching Guide</a>.</p>
 | 
						||
</div>
 | 
						||
<div id="quickview"><h3 class="directives">Directives</h3>
 | 
						||
<ul id="toc">
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachedefaultexpire">CacheDefaultExpire</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachedisable">CacheDisable</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheenable">CacheEnable</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheignorecachecontrol">CacheIgnoreCacheControl</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheignoreheaders">CacheIgnoreHeaders</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheignorenolastmod">CacheIgnoreNoLastMod</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheignorequerystring">CacheIgnoreQueryString</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachelastmodifiedfactor">CacheLastModifiedFactor</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachemaxexpire">CacheMaxExpire</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cacheminexpire">CacheMinExpire</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachestorenostore">CacheStoreNoStore</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#cachestoreprivate">CacheStorePrivate</a></li>
 | 
						||
</ul>
 | 
						||
<h3>Topics</h3>
 | 
						||
<ul id="topics">
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#related">Related Modules and Directives</a></li>
 | 
						||
<li><img alt="" src="../images/down.gif" /> <a href="#sampleconf">Sample Configuration</a></li>
 | 
						||
</ul><h3>See also</h3>
 | 
						||
<ul class="seealso">
 | 
						||
<li><a href="../caching.html">Caching Guide</a></li>
 | 
						||
</ul></div>
 | 
						||
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						||
<div class="section">
 | 
						||
<h2><a name="related" id="related">Related Modules and Directives</a></h2>
 | 
						||
    <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code></li></ul></td><td><ul><li><code class="directive"><a href="../mod/mod_disk_cache.html#cacheroot">CacheRoot</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachedirlevels">CacheDirLevels</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachedirlength">CacheDirLength</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cacheminfilesize">CacheMinFileSize</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachemaxfilesize">CacheMaxFileSize</a></code></li></ul></td></tr></table>
 | 
						||
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 | 
						||
<div class="section">
 | 
						||
<h2><a name="sampleconf" id="sampleconf">Sample Configuration</a></h2>
 | 
						||
    <div class="example"><h3>Sample httpd.conf</h3><p><code>
 | 
						||
      #<br />
 | 
						||
      # Sample Cache Configuration<br />
 | 
						||
      #<br />
 | 
						||
      LoadModule cache_module modules/mod_cache.so<br />
 | 
						||
      <br />
 | 
						||
      <IfModule mod_cache.c><br />
 | 
						||
      <span class="indent">
 | 
						||
        LoadModule disk_cache_module modules/mod_disk_cache.so<br />
 | 
						||
        <IfModule mod_disk_cache.c><br />
 | 
						||
        <span class="indent">
 | 
						||
          CacheRoot c:/cacheroot<br />
 | 
						||
          CacheEnable disk  /<br />
 | 
						||
          CacheDirLevels 5<br />
 | 
						||
          CacheDirLength 3<br />
 | 
						||
        </span>
 | 
						||
        </IfModule> <br />
 | 
						||
        <br />
 | 
						||
        # When acting as a proxy, don't cache the list of security updates<br />
 | 
						||
        CacheDisable http://security.update.server/update-list/<br />
 | 
						||
      </span>
 | 
						||
      </IfModule>
 | 
						||
    </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="CacheDefaultExpire" id="CacheDefaultExpire">CacheDefaultExpire</a> <a name="cachedefaultexpire" id="cachedefaultexpire">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The default duration to cache a document when no expiry date is specified.</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheDefaultExpire <var>seconds</var></code></td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheDefaultExpire 3600 (one hour)</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">CacheDefaultExpire</code> directive specifies a default time,
 | 
						||
    in seconds, to cache a document if neither an expiry date nor last-modified date are provided
 | 
						||
    with the document. The value specified with the <code class="directive">CacheMaxExpire</code>
 | 
						||
    directive does <em>not</em> override this setting.</p>
 | 
						||
 | 
						||
    <div class="example"><p><code>
 | 
						||
      CacheDefaultExpire 86400
 | 
						||
    </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="CacheDisable" id="CacheDisable">CacheDisable</a> <a name="cachedisable" id="cachedisable">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Disable caching of specified URLs</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheDisable <var> url-string</var></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">CacheDisable</code> directive instructs
 | 
						||
    <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> to <em>not</em> cache urls at or below
 | 
						||
    <var>url-string</var>.</p>
 | 
						||
 | 
						||
    <div class="example"><h3>Example</h3><p><code>
 | 
						||
      CacheDisable /local_files
 | 
						||
    </code></p></div>
 | 
						||
 | 
						||
    <p> The <code>no-cache</code> environment variable can be set to 
 | 
						||
    disable caching on a finer grained set of resources.</p>
 | 
						||
 | 
						||
<h3>See also</h3>
 | 
						||
<ul>
 | 
						||
<li><a href="../env.html">Environment Variables in Apache</a></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="CacheEnable" id="CacheEnable">CacheEnable</a> <a name="cacheenable" id="cacheenable">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enable caching of specified URLs using a specified storage
 | 
						||
manager</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheEnable <var>cache_type</var> <var>url-string</var></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">CacheEnable</code> directive instructs
 | 
						||
    <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> to cache urls at or below
 | 
						||
    <var>url-string</var>. The cache storage manager is specified with the
 | 
						||
    <var>cache_type</var> argument. 
 | 
						||
    <var>cache_type</var> <code>disk</code> instructs
 | 
						||
    <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> to use the disk based storage manager
 | 
						||
    implemented by <code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code>.</p>
 | 
						||
    <p>In the event that the URL space overlaps between different
 | 
						||
    <code class="directive">CacheEnable</code> directives (as in the example below),
 | 
						||
    each possible storage manager will be run until the first one that
 | 
						||
    actually processes the request. The order in which the storage managers are
 | 
						||
    run is determined by the order of the <code class="directive">CacheEnable</code>
 | 
						||
    directives in the configuration file.</p>
 | 
						||
 | 
						||
    <p>When acting as a forward proxy server, <var>url-string</var> can
 | 
						||
    also be used to specify remote sites and proxy protocols which 
 | 
						||
    caching should be enabled for.</p>
 | 
						||
 
 | 
						||
    <div class="example"><p><code>
 | 
						||
      # Cache proxied url's<br />
 | 
						||
      CacheEnable  disk  /<br /><br />
 | 
						||
      # Cache FTP-proxied url's<br />
 | 
						||
      CacheEnable  disk  ftp://<br /><br />
 | 
						||
      # Cache content from www.apache.org<br />
 | 
						||
      CacheEnable  disk  http://www.apache.org/<br />
 | 
						||
    </code></p></div>
 | 
						||
 | 
						||
    <p> The <code>no-cache</code> environment variable can be set to 
 | 
						||
    disable caching on a finer grained set of resources.</p>
 | 
						||
 | 
						||
 | 
						||
<h3>See also</h3>
 | 
						||
<ul>
 | 
						||
<li><a href="../env.html">Environment Variables in Apache</a></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="CacheIgnoreCacheControl" id="CacheIgnoreCacheControl">CacheIgnoreCacheControl</a> <a name="cacheignorecachecontrol" id="cacheignorecachecontrol">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ignore request to not serve cached content to client</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheIgnoreCacheControl On|Off</code></td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheIgnoreCacheControl 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 containing a Cache-Control: no-cache or
 | 
						||
    Pragma: no-cache header value will not be served from the cache.  The
 | 
						||
    <code class="directive">CacheIgnoreCacheControl</code> directive allows this
 | 
						||
    behavior to be overridden.  <code class="directive">CacheIgnoreCacheControl</code>
 | 
						||
    On tells the server to attempt to serve the resource from the cache even
 | 
						||
    if the request contains no-cache header values.  Resources requiring
 | 
						||
    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="CacheIgnoreQueryString" id="CacheIgnoreQueryString">CacheIgnoreQueryString</a> <a name="cacheignorequerystring" id="cacheignorequerystring">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ignore query string when caching</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheIgnoreQueryString On|Off</code></td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheIgnoreQueryString 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 with query string parameters are cached separately
 | 
						||
    for each unique query string. This is according to RFC 2616/13.9 done only
 | 
						||
    if an expiration time is specified. The 
 | 
						||
    <code class="directive">CacheIgnoreQueryString</code> directive tells the cache to
 | 
						||
    cache requests even if no expiration time is specified, and to reply with 
 | 
						||
    a cached reply even if the query string differs. From a caching point of
 | 
						||
    view the request is treated as if having no query string when this 
 | 
						||
    directive is enabled.</p>
 | 
						||
 | 
						||
    <div class="example"><p><code>
 | 
						||
      CacheIgnoreQueryString 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="CacheMinExpire" id="CacheMinExpire">CacheMinExpire</a> <a name="cacheminexpire" id="cacheminexpire">Directive</a></h2>
 | 
						||
<table class="directive">
 | 
						||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The minimum time in seconds to cache a document</td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheMinExpire <var>seconds</var></code></td></tr>
 | 
						||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheMinExpire 0</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">CacheMinExpire</code> directive specifies the minimum number of
 | 
						||
    seconds for which cachable HTTP documents will be retained without checking the origin
 | 
						||
    server. This is only used if no valid expire time was supplied with the document.</p>
 | 
						||
 | 
						||
 | 
						||
    <div class="example"><p><code>
 | 
						||
      CacheMinExpire 3600
 | 
						||
    </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>
 | 
						||
<div class="bottomlang">
 | 
						||
<p><span>Available Languages: </span><a href="../en/mod/mod_cache.html" title="English"> en </a> |
 | 
						||
<a href="../ja/mod/mod_cache.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
 | 
						||
<a href="../ko/mod/mod_cache.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p>
 | 
						||
</div><div id="footer">
 | 
						||
<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
 | 
						||
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
 | 
						||
</body></html> |