home *** CD-ROM | disk | FTP | other *** search
/ PC World 2006 July & August / PCWorld_2006-07-08_cd.bin / komunikace / apache / apache_2[1].2.2-win32-x86-no_ssl.msi / Data1.cab / _A359F4E5DA8175C920CC3F3A3416FCAA < prev    next >
Extensible Markup Language  |  2006-01-15  |  16KB  |  236 lines
  1. <?xml version="1.0" encoding="ISO-8859-1"?>
  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
  3. <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
  4.         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
  5.               This file is generated from xml source: DO NOT EDIT
  6.         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
  7.       -->
  8. <title>mod_mem_cache - Apache HTTP Server</title>
  9. <link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
  10. <link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
  11. <link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
  12. <link href="../images/favicon.ico" rel="shortcut icon" /></head>
  13. <body>
  14. <div id="page-header">
  15. <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>
  16. <p class="apache">Apache HTTP Server Version 2.2</p>
  17. <img alt="" src="../images/feather.gif" /></div>
  18. <div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
  19. <div id="path">
  20. <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 2.2</a> > <a href="./">Modules</a></div>
  21. <div id="page-content">
  22. <div id="preamble"><h1>Apache Module mod_mem_cache</h1>
  23. <div class="toplang">
  24. <p><span>Available Languages: </span><a href="../en/mod/mod_mem_cache.html" title="English"> en </a> |
  25. <a href="../ja/mod/mod_mem_cache.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
  26. <a href="../ko/mod/mod_mem_cache.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p>
  27. </div>
  28. <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Content cache keyed to URIs</td></tr>
  29. <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  30. <tr><th><a href="module-dict.html#ModuleIdentifier">ModuleáIdentifier:</a></th><td>mem_cache_module</td></tr>
  31. <tr><th><a href="module-dict.html#SourceFile">SourceáFile:</a></th><td>mod_mem_cache.c</td></tr></table>
  32. <h3>Summary</h3>
  33.  
  34.     <p>This module <em>requires</em> the service of <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>. It acts as a support module for <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> and provides a memory based storage manager.
  35.     <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code> can be configured to operate in two
  36.     modes: caching open file descriptors or caching objects in heap storage.
  37.     <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code> is most useful when used to cache locally
  38.     generated content or to cache backend server content for <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> configured for <code class="directive"><a href="../mod/mod_proxy.html#proxypass">ProxyPass</a></code> (aka <dfn>reverse proxy</dfn>).</p>
  39.  
  40.     <p>Content is stored in and retrieved from the cache using URI based
  41.     keys. Content with access protection is not cached.</p>
  42. </div>
  43. <div id="quickview"><h3 class="directives">Directives</h3>
  44. <ul id="toc">
  45. <li><img alt="" src="../images/down.gif" /> <a href="#mcachemaxobjectcount">MCacheMaxObjectCount</a></li>
  46. <li><img alt="" src="../images/down.gif" /> <a href="#mcachemaxobjectsize">MCacheMaxObjectSize</a></li>
  47. <li><img alt="" src="../images/down.gif" /> <a href="#mcachemaxstreamingbuffer">MCacheMaxStreamingBuffer</a></li>
  48. <li><img alt="" src="../images/down.gif" /> <a href="#mcacheminobjectsize">MCacheMinObjectSize</a></li>
  49. <li><img alt="" src="../images/down.gif" /> <a href="#mcacheremovalalgorithm">MCacheRemovalAlgorithm</a></li>
  50. <li><img alt="" src="../images/down.gif" /> <a href="#mcachesize">MCacheSize</a></li>
  51. </ul>
  52. <h3>See also</h3>
  53. <ul class="seealso">
  54. <li><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code></li>
  55. <li><code class="module"><a href="../mod/mod_disk_cache.html">mod_disk_cache</a></code></li>
  56. </ul></div>
  57.  
  58. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  59. <div class="directive-section"><h2><a name="MCacheMaxObjectCount" id="MCacheMaxObjectCount">MCacheMaxObjectCount</a> <a name="mcachemaxobjectcount" id="mcachemaxobjectcount">Directive</a></h2>
  60. <table class="directive">
  61. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The maximum number of objects allowed to be placed in the
  62. cache</td></tr>
  63. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheMaxObjectCount <var>value</var></code></td></tr>
  64. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheMaxObjectCount 1009</code></td></tr>
  65. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  66. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  67. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  68. </table>
  69.     <p>The <code class="directive">MCacheMaxObjectCount</code> directive sets the
  70.     maximum number of objects to be cached. The value is used to create the
  71.     open hash table. If a new object needs to be inserted in the cache and
  72.     the maximum number of objects has been reached, an object will be
  73.     removed to allow the new object to be cached. The object to be removed
  74.     is selected using the algorithm specified by <code class="directive"><a href="#mcacheremovalalgorithm">MCacheRemovalAlgorithm</a></code>.</p>
  75.  
  76.     <div class="example"><h3>Example</h3><p><code>
  77.       MCacheMaxObjectCount 13001
  78.     </code></p></div>
  79.  
  80. </div>
  81. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  82. <div class="directive-section"><h2><a name="MCacheMaxObjectSize" id="MCacheMaxObjectSize">MCacheMaxObjectSize</a> <a name="mcachemaxobjectsize" id="mcachemaxobjectsize">Directive</a></h2>
  83. <table class="directive">
  84. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The maximum size (in bytes) of a document allowed in the
  85. cache</td></tr>
  86. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheMaxObjectSize <var>bytes</var></code></td></tr>
  87. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheMaxObjectSize 10000</code></td></tr>
  88. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  89. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  90. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  91. </table>
  92.     <p>The <code class="directive">MCacheMaxObjectSize</code> directive sets the
  93.     maximum allowable size, in bytes, of a document for it to be considered
  94.     cacheable.</p>
  95.  
  96.     <div class="example"><h3>Example</h3><p><code>
  97.       MCacheMaxObjectSize 6400000
  98.     </code></p></div>
  99.  
  100.     <div class="note"><h3>Note</h3>
  101.       <p>The value of <code class="directive">MCacheMaxObjectSize</code> must be
  102.       greater than the value specified by the <code class="directive"><a href="#mcacheminobjectsize">MCacheMinObjectSize</a></code> directive.</p>
  103.     </div>
  104.  
  105. </div>
  106. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  107. <div class="directive-section"><h2><a name="MCacheMaxStreamingBuffer" id="MCacheMaxStreamingBuffer">MCacheMaxStreamingBuffer</a> <a name="mcachemaxstreamingbuffer" id="mcachemaxstreamingbuffer">Directive</a></h2>
  108. <table class="directive">
  109. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximum amount of a streamed response to buffer in memory
  110. before declaring the response uncacheable</td></tr>
  111. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheMaxStreamingBuffer <var>size_in_bytes</var></code></td></tr>
  112. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheMaxStreamingBuffer the smaller of 100000 or MCacheMaxObjectSize</code></td></tr>
  113. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  114. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  115. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  116. </table>
  117.     <p>The <code class="directive">MCacheMaxStreamingBuffer</code> directive
  118.     specifies the maximum number of bytes of a streamed response to
  119.     buffer before deciding that the response is too big to cache.
  120.     A streamed response is one in which the entire content is not
  121.     immediately available and in which the <code>Content-Length</code>
  122.     may not be known. Sources of streaming responses include proxied
  123.     responses and the output of CGI scripts. By default, a streamed
  124.     response will <em>not</em> be cached unless it has a
  125.     <code>Content-Length</code> header. The reason for this is to
  126.     avoid using a large amount of memory to buffer a partial response
  127.     that might end up being too large to fit in the cache.
  128.     The <code class="directive">MCacheMaxStreamingBuffer</code> directive allows
  129.     buffering of streamed responses that don't contain a
  130.     <code>Content-Length</code> up to the specified maximum amount of
  131.     space. If the maximum buffer space is reached, the buffered
  132.     content is discarded and the attempt to cache is abandoned.</p>
  133.  
  134.     <div class="note"><h3>Note:</h3>
  135.       <p>Using a nonzero value for <code class="directive">MCacheMaxStreamingBuffer</code> 
  136.       will not delay the transmission of the response to the client.
  137.       As soon as <code class="module"><a href="../mod/mod_mem_cache.html">mod_mem_cache</a></code> copies a block of streamed
  138.       content into a buffer, it sends the block on to the next output
  139.       filter for delivery to the client.</p>
  140.     </div>
  141.  
  142.     <div class="example"><p><code>
  143.       # Enable caching of streamed responses up to 64KB:<br />
  144.       MCacheMaxStreamingBuffer 65536
  145.     </code></p></div>
  146.  
  147. </div>
  148. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  149. <div class="directive-section"><h2><a name="MCacheMinObjectSize" id="MCacheMinObjectSize">MCacheMinObjectSize</a> <a name="mcacheminobjectsize" id="mcacheminobjectsize">Directive</a></h2>
  150. <table class="directive">
  151. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The minimum size (in bytes) of a document to be allowed in the
  152. cache</td></tr>
  153. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheMinObjectSize <var>bytes</var></code></td></tr>
  154. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheMinObjectSize 0</code></td></tr>
  155. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  156. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  157. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  158. </table>
  159.     <p>The <code class="directive">MCacheMinObjectSize</code> directive sets the
  160.     minimum size in bytes of a document for it to be considered
  161.     cacheable.</p>
  162.  
  163.     <div class="example"><h3>Example</h3><p><code>
  164.       MCacheMinObjectSize 10000
  165.     </code></p></div>
  166.  
  167. </div>
  168. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  169. <div class="directive-section"><h2><a name="MCacheRemovalAlgorithm" id="MCacheRemovalAlgorithm">MCacheRemovalAlgorithm</a> <a name="mcacheremovalalgorithm" id="mcacheremovalalgorithm">Directive</a></h2>
  170. <table class="directive">
  171. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The algorithm used to select documents for removal from the
  172. cache</td></tr>
  173. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheRemovalAlgorithm LRU|GDSF</code></td></tr>
  174. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheRemovalAlgorithm GDSF</code></td></tr>
  175. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  176. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  177. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  178. </table>
  179.     <p>The <code class="directive">MCacheRemovalAlgorithm</code> directive specifies
  180.     the algorithm used to select documents for removal from the cache.
  181.     Two choices are available:</p>
  182.  
  183.     <dl>
  184.       <dt><code>LRU</code> (Least Recently Used)</dt>
  185.       <dd><code>LRU</code> removes the documents that have not been accessed
  186.       for the longest time.</dd>
  187.  
  188.       <dt><code>GDSF</code> (GreadyDual-Size)</dt>
  189.       <dd><code>GDSF</code> assigns a priority to cached documents based
  190.       on the cost of a cache miss and the size of the document. Documents
  191.       with the lowest priority are removed first.</dd>
  192.     </dl>
  193.  
  194.     <div class="example"><h3>Example</h3><p><code>
  195.       MCacheRemovalAlgorithm GDSF<br />
  196.       MCacheRemovalAlgorithm LRU
  197.     </code></p></div>
  198.  
  199. </div>
  200. <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  201. <div class="directive-section"><h2><a name="MCacheSize" id="MCacheSize">MCacheSize</a> <a name="mcachesize" id="mcachesize">Directive</a></h2>
  202. <table class="directive">
  203. <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>The maximum amount of memory used by the cache in
  204. KBytes</td></tr>
  205. <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MCacheSize <var>KBytes</var></code></td></tr>
  206. <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MCacheSize 100</code></td></tr>
  207. <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
  208. <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
  209. <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_mem_cache</td></tr>
  210. </table>
  211.     <p>The <code class="directive">MCacheSize</code> directive sets the maximum
  212.     amount of memory to be used by the cache, in KBytes (1024-byte units).
  213.     If a new object needs to be inserted in the cache and the size of the
  214.     object is greater than the remaining memory, objects will be removed
  215.     until the new object can be cached. The object to be removed is
  216.     selected using the algorithm specified by <code class="directive"><a href="#mcacheremovalalgorithm">MCacheRemovalAlgorithm</a></code>.</p>
  217.  
  218.     <div class="example"><h3>Example</h3><p><code>
  219.       MCacheSize 700000
  220.     </code></p></div>
  221.  
  222.     <div class="note"><h3>Note</h3>
  223.       <p>The <code class="directive">MCacheSize</code> value must be greater than
  224.       the value specified by the <code class="directive"><a href="#mcachemaxobjectsize">MCacheMaxObjectSize</a></code> directive.</p>
  225.     </div>
  226.  
  227. </div>
  228. </div>
  229. <div class="bottomlang">
  230. <p><span>Available Languages: </span><a href="../en/mod/mod_mem_cache.html" title="English"> en </a> |
  231. <a href="../ja/mod/mod_mem_cache.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
  232. <a href="../ko/mod/mod_mem_cache.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p>
  233. </div><div id="footer">
  234. <p class="apache">Copyright 1995-2006 The Apache Software Foundation or its licensors, as applicable.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
  235. <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>
  236. </body></html>