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author | 2015-11-30 01:45:08 -0500 | |
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committer | 2015-11-30 01:45:08 -0500 | |
commit | e8ec7aa8e38a93f5b034ac74cebce5de23710317 (patch) | |
tree | aa031937bf856c1f8d6ad7877b8d2cb0224da5ef /rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en | |
parent | cc40af334e619bb549038238507407866f774f8f (diff) |
upload http
JIRA: BOTTLENECK-10
Change-Id: I7598427ff904df438ce77c2819ee48ac75ffa8da
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>
Diffstat (limited to 'rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en')
-rw-r--r-- | rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en b/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en new file mode 100644 index 00000000..8be49fbb --- /dev/null +++ b/rubbos/app/httpd-2.0.64/docs/manual/mod/mod_cache.html.en @@ -0,0 +1,387 @@ +<?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 2.0</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 2.0</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="../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>Experimental</td></tr> +<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>cache_module</td></tr> +<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_cache.c</td></tr></table> +<h3>Summary</h3> + + <div class="warning"> + This module is experimental. Documentation is still under development... + </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. Two storage management modules are 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> + + <dt><code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code></dt> + <dd>implements a memory based storage manager. + <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code> can be configured to operate in two + modes: caching open file descriptors or caching objects in heap storage. + <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code> can be used to cache locally generated content + or to cache backend server content for <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> when + configured using <code class="directive"><a href="../mod/mod_proxy.html#proxypass">ProxyPass</a></code> + (aka <dfn>reverse proxy</dfn>)</dd> + </dl> + + <p>Content is stored in and retrieved from the cache using URI based keys. Content with + access protection is not cached.</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="#cacheforcecompletion">CacheForceCompletion</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="#cachelastmodifiedfactor">CacheLastModifiedFactor</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#cachemaxexpire">CacheMaxExpire</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></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><li><code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_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#cachesize">CacheSize</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachegcinterval">CacheGcInterval</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#cacheexpirycheck">CacheExpiryCheck</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><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachetimemargin">CacheTimeMargin</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachegcdaily">CacheGcDaily</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachegcunused">CacheGcUnused</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachegcclean">CacheGcClean</a></code></li><li><code class="directive"><a href="../mod/mod_disk_cache.html#cachegcmemusage">CacheGcMemUsage</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcachesize">MCacheSize</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcachemaxobjectcount">MCacheMaxObjectCount</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcacheminobjectsize">MCacheMinObjectSize</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcachemaxobjectsize">MCacheMaxObjectSize</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcacheremovalalgorithm">MCacheRemovalAlgorithm</a></code></li><li><code class="directive"><a href="../mod/mod_mem_cache.html#mcachemaxstreamingbuffer">MCacheMaxStreamingBuffer</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 /> + CacheSize 256<br /> + CacheEnable disk /<br /> + CacheDirLevels 5<br /> + CacheDirLength 3<br /> + </span> + </IfModule> <br /> + <br /> + LoadModule mem_cache_module modules/mod_mem_cache.so<br /> + <IfModule mod_mem_cache.c><br /> + <span class="indent"> + CacheEnable mem /<br /> + MCacheSize 4096<br /> + MCacheMaxObjectCount 100<br /> + MCacheMinObjectSize 1<br /> + MCacheMaxObjectSize 2048<br /> + </span> + </IfModule><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>Experimental</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>Experimental</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> + +</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>Experimental</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> mem</code> + instructs <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> to use the memory based storage + manager implemented by <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code>. + <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>. + <var>cache_type</var> <code>fd</code> instructs + <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> to use the file descriptor cache implemented + by <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_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> + + <div class="example"><p><code> + CacheEnable mem /manual<br /> + CacheEnable fd /images<br /> + CacheEnable disk /<br /> + </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="CacheForceCompletion" id="CacheForceCompletion">CacheForceCompletion</a> <a name="cacheforcecompletion" id="cacheforcecompletion">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Percentage of document served, after which the server +will complete caching the file even if the request is cancelled.</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CacheForceCompletion <var>Percentage</var></code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>CacheForceCompletion 60</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>Experimental</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr> +</table> + <p>Ordinarily, if a request is cancelled while the response is being + cached and delivered to the client the processing of the response will + stop and the cache entry will be removed. The + <code class="directive">CacheForceCompletion</code> directive specifies a + threshold beyond which the document will continue to be cached to + completion, even if the request is cancelled.</p> + + <p>The threshold is a percentage specified as a value between + <code>1</code> and <code>100</code>. A value of <code>0</code> + specifies that the default be used. A value of <code>100</code> + will only cache documents that are served in their entirety. A value + between 60 and 90 is recommended.</p> + + <div class="example"><p><code> + CacheForceCompletion 80 + </code></p></div> + + <div class="warning"><h3>Note:</h3> + This feature is currently <em>not</em> implemented. + </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="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 the fact that the client requested the content not be +cached.</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>Experimental</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_cache</td></tr> +</table> + <p>Ordinarily, documents with no-cache or no-store header values will not be stored in 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 cache the document + even if it contains no-cache or no-store header values. Documents requiring authorization will + <em>never</em> be cached.</p> + + <div class="example"><p><code> + CacheIgnoreCacheControl 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="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>Experimental</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>Experimental</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>Experimental</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>Experimental</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> +<div class="bottomlang"> +<p><span>Available Languages: </span><a href="../en/mod/mod_cache.html" title="English"> en </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>
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