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| author | Joshua Slive <slive@apache.org> | 2002-05-23 16:21:19 +0200 |
|---|---|---|
| committer | Joshua Slive <slive@apache.org> | 2002-05-23 16:21:19 +0200 |
| commit | 8ec75c12fa304b02449d12d3e6a834b836086fd7 (patch) | |
| tree | c8061830a61085b02ebd2dacbbca18bd8780c836 /docs/manual/mod/mod_file_cache.html | |
| parent | Add "-k start|startssl|restart|graceful|stop" support to httpd (diff) | |
| download | apache2-8ec75c12fa304b02449d12d3e6a834b836086fd7.tar.xz apache2-8ec75c12fa304b02449d12d3e6a834b836086fd7.zip | |
Thanks to Yoshiki, we seem to have an (at least temporary) solution to our
doc transformation problem.
As the first step, I'm removing all the .html files. They will be replaced
by language-specific files.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95238 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'docs/manual/mod/mod_file_cache.html')
| -rw-r--r-- | docs/manual/mod/mod_file_cache.html | 147 |
1 files changed, 0 insertions, 147 deletions
diff --git a/docs/manual/mod/mod_file_cache.html b/docs/manual/mod/mod_file_cache.html deleted file mode 100644 index 3ba27d0620..0000000000 --- a/docs/manual/mod/mod_file_cache.html +++ /dev/null @@ -1,147 +0,0 @@ -<html xmlns="http://www.w3.org/TR/xhtml1/strict"><head><!-- - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - This file is generated from xml source: DO NOT EDIT - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - --><title>mod_file_cache- Apache HTTP Server</title><link href="../style/manual.css" type="text/css" rel="stylesheet"/></head><body><blockquote><div align="center"><img src="../images/sub.gif" alt="[APACHE DOCUMENTATION]"/><h3>Apache HTTP Server Version 2.0</h3></div><h1 align="center">Apache Module mod_file_cache</h1><table cellspacing="1" cellpadding="0" bgcolor="#cccccc"><tr><td><table bgcolor="#ffffff"><tr><td valign="top"><span class="help">Description:</span></td><td>Caches a static list of files in memory</td></tr><tr><td><a href="module-dict.html#Status" class="help">Status:</a></td><td>Experimental</td></tr><tr><td><a href="module-dict.html#ModuleIdentifier" class="help">Module Identifier:</a></td><td>file_cache_module</td></tr></table></td></tr></table><h2>Summary</h2> - -<blockquote><table><tr><td bgcolor="#ffe5f5"> -This module should be used with care. You can easily - create a broken site using mod_file_cache, so read this - document carefully. -</td></tr></table></blockquote> - - <p><em>Caching</em> frequently requested files that change very - infrequently is a technique for reducing server load. - mod_file_cache provides two techniques for caching frequently - requested <em>static</em> files. Through configuration - directives, you can direct mod_file_cache to either open then - mmap()a file, or to pre-open a file and save the file's open - <em>file handle</em>. Both techniques reduce server load when - processing requests for these files by doing part of the work - (specifically, the file I/O) for serving the file when the - server is started rather than during each request.</p> - - <p>Notice: You cannot use this for speeding up CGI programs or - other files which are served by special content handlers. It - can only be used for regular files which are usually served by - the Apache core content handler.</p> - - <p>This module is an extension of and borrows heavily from the - mod_mmap_static module in Apache 1.3.</p> -<h2>Directives</h2><ul><li><a href="#cachefile">CacheFile</a></li><li><a href="#mmapfile">MMapFile</a></li></ul><h2>Using mod_file_cache</h2> - - <p><code><a href="mod_file_cache.html">mod_file_cache</a></code> caches a list of statically - configured files via <a href="#mmapfile" class="directive"><code class="directive">MMapFile</code></a> or <a href="#cachefile" class="directive"><code class="directive">CacheFile</code></a> directives in the - main server configuration.</p> - - <p>Not all platforms support both directives. For example, Apache - on Windows does not currently support the <a href="#mmapstatic" class="directive"><code class="directive">MMapStatic</code></a> directive, while - other platforms, like AIX, support both. You will receive an error - message in the server error log if you attempt to use an - unsupported directive. If given an unsupported directive, the - server will start but the file will not be cached. On platforms - that support both directives, you should experiment with both to - see which works best for you.</p> - -<h3>MmapFile Directive</h3> - - <p>The <a href="#mmapfile" class="directive"><code class="directive">MmapFile</code></a> - directive of <code><a href="mod_file_cache.html">mod_file_cache</a></code> maps a list of - statically configured files into memory through the system call - <code>mmap()</code>. This system call is available on most modern - Unix derivates, but not on all. There are sometimes - system-specific limits on the size and number of files that can be - mmap()d, experimentation is probably the easiest way to find - out.</p> - - <p>This mmap()ing is done once at server start or restart, - only. So whenever one of the mapped files changes on the - filesystem you <em>have</em> to restart the server (see the <a href="../stopping.html">Stopping and Restarting</a> - documentation). To reiterate that point: if the files are - modified <em>in place</em> without restarting the server you - may end up serving requests that are completely bogus. You - should update files by unlinking the old copy and putting a new - copy in place. Most tools such as <code>rdist</code> and - <code>mv</code> do this. The reason why this modules doesn't - take care of changes to the files is that this check would need - an extra <code>stat()</code> every time which is a waste and - against the intent of I/O reduction.</p> - - -<h3>CacheFile Directive</h3> - - <p>The <a href="#cachefile" class="directive"><code class="directive">CacheFile</code></a> - directive of <code><a href="mod_file_cache.html">mod_file_cache</a></code> opens an active - <em>handle</em> or <em>file descriptor</em> to the file (or files) - listed in the configuration directive and places these open file - handles in the cache. When the file is requested, the server - retrieves the handle from the cache and passes it to the - sendfile() (or TransmitFile() on Windows), socket API.</p> - - <p>Insert more details about sendfile API...</p> - - <p>This file handle caching is done once at server start or - restart, only. So whenever one of the cached files changes on - the filesystem you <em>have</em> to restart the server (see the - <a href="../stopping.html">Stopping and Restarting</a> - documentation). To reiterate that point: if the files are - modified <em>in place</em> without restarting the server you - may end up serving requests that are completely bogus. You - should update files by unlinking the old copy and putting a new - copy in place. Most tools such as <code>rdist</code> and - <code>mv</code> do this.</p> - - -<blockquote><table><tr><td bgcolor="#e0e5f5"><p align="center"><strong>Note</strong></p> Don't bother asking for a for a - directive which recursively caches all the files in a - directory. Try this instead... See the - <a href="core.html#include" class="directive"><code class="directive">Include</code></a> directive, and consider - this command: -<blockquote><table cellpadding="10"><tr><td bgcolor="#eeeeee"><code> - find /www/htdocs -type f -print \ <br> - | sed -e 's/.*/mmapfile &/' > /www/conf/mmap.conf -</code></td></tr></table></blockquote> -</td></tr></table></blockquote> - -<hr/><h2><a name="CacheFile">CacheFile</a> <a name="cachefile">Directive</a></h2><table cellpadding="1" cellspacing="0" border="0" bgcolor="#cccccc"><tr><td><table bgcolor="#ffffff"><tr><td><strong>Description: </strong></td><td/></tr><tr><td><a href="directive-dict.html#Syntax" class="help">Syntax:</a></td><td>CacheFile - <em>file-path</em> [<em>file-path</em>] ...</td></tr><tr><td><a href="directive-dict.html#Context" class="help">Context:</a></td><td>server config</td></tr><tr><td><a href="directive-dict.html#Status" class="help">Status:</a></td><td>Experimental</td></tr><tr><td><a href="directive-dict.html#Module" class="help">Module:</a></td><td>mod_file_cache</td></tr></table></td></tr></table> - <p>The <code class="directive">CacheFile</code> directive opens handles to - one or more files (given as whitespace separated arguments) and - places these handles into the cache at server startup - time. Handles to cached files are automatically closed on a server - shutdown. When the files have changed on the filesystem, the - server should be restarted to to re-cache them.</p> - - <p>Be careful with the <em>file-path</em> arguments: They have - to literally match the filesystem path Apache's URL-to-filename - translation handlers create. We cannot compare inodes or other - stuff to match paths through symbolic links <em>etc.</em> - because that again would cost extra <code>stat()</code> system - calls which is not acceptable. This module may or may not work - with filenames rewritten by <code><a href="mod_alias.html">mod_alias</a></code> or - <code><a href="mod_rewrite.html">mod_rewrite</a></code>.</p> - -<blockquote><table cellpadding="10"><tr><td bgcolor="#eeeeee"><p align="center"><strong>Example</strong></p><code> - CacheFile /usr/local/apache/htdocs/index.html -</code></td></tr></table></blockquote> -<hr/><h2><a name="MMapFile">MMapFile</a> <a name="mmapfile">Directive</a></h2><table cellpadding="1" cellspacing="0" border="0" bgcolor="#cccccc"><tr><td><table bgcolor="#ffffff"><tr><td><strong>Description: </strong></td><td/></tr><tr><td><a href="directive-dict.html#Syntax" class="help">Syntax:</a></td><td>MMapFile <em>file-path</em> [<em>file-path</em>] ...</td></tr><tr><td><a href="directive-dict.html#Context" class="help">Context:</a></td><td>server config</td></tr><tr><td><a href="directive-dict.html#Status" class="help">Status:</a></td><td>Experimental</td></tr><tr><td><a href="directive-dict.html#Module" class="help">Module:</a></td><td>mod_file_cache</td></tr></table></td></tr></table> - <p>The <code class="directive">MMapFile</code> directive maps one or more files - (given as whitespace separated arguments) into memory at server - startup time. They are automatically unmapped on a server - shutdown. When the files have changed on the filesystem at - least a HUP or USR1 signal should be send to the server to - re-mmap them.</p> - - <p>Be careful with the <em>file-path</em> arguments: They have - to literally match the filesystem path Apache's URL-to-filename - translation handlers create. We cannot compare inodes or other - stuff to match paths through symbolic links <em>etc.</em> - because that again would cost extra <code>stat()</code> system - calls which is not acceptable. This module may or may not work - with filenames rewritten by <code><a href="mod_alias.html">mod_alias</a></code> or - <code><a href="mod_rewrite.html">mod_rewrite</a></code>.</p> - -<blockquote><table cellpadding="10"><tr><td bgcolor="#eeeeee"><p align="center"><strong>Example</strong></p><code> - MMapFile /usr/local/apache/htdocs/index.html -</code></td></tr></table></blockquote> -<hr/></blockquote><h3 align="center">Apache HTTP Server Version 2.0</h3><a href="./"><img src="../images/index.gif" alt="Index"/></a><a href="../"><img src="../images/home.gif" alt="Home"/></a></body></html>
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