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diff --git a/docs/manual/mod/mod_file_cache.html b/docs/manual/mod/mod_file_cache.html deleted file mode 100644 index 8e8b34325b..0000000000 --- a/docs/manual/mod/mod_file_cache.html +++ /dev/null @@ -1,268 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> -<HTML> - <HEAD> - <TITLE>Apache module mod_file_cache</TITLE> - </HEAD> -<!-- Background white, links blue (unvisited), navy (visited), red (active) --> - <BODY - BGCOLOR="#FFFFFF" - TEXT="#000000" - LINK="#0000FF" - VLINK="#000080" - ALINK="#FF0000" - > -<!--#include virtual="header.html" --> - <H1 ALIGN="CENTER">Module mod_file_cache</H1> - <P> - <STRONG>This module should be used with care. You can easily create a - broken site using mod_file_cache, so read this document - carefully.</STRONG> - </P> - - <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> - <CODE>mod_file_cache</CODE> is not compiled into the server by - default. To use <CODE>mod_file_cache</CODE> you have to enable the - following line in the server build <CODE>Configuration</CODE> file: - <PRE> - AddModule modules/experimental/mod_file_cache.o - </PRE> - </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>Summary</H2> - <P> - <CODE>mod_file_cache</CODE> caches a list of statically configured - files via <CODE>MMapFile</CODE> or <CODE>CacheFile</CODE> directives - in the main server configuration. - </P> - - <P> - Not all platforms support both directives. For - example, Apache on Windows does not currently support the MMapStatic - 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><CODE>MmapFile</CODE> Directive </H3> - <P> - The <CODE>MmapFile</CODE> directive of <CODE>mod_file_cache</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><CODE>CacheFile</CODE> Directive </H3> - <P> - The <CODE>CacheFile</CODE> directive of <CODE>mod_file_cache</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> - - <H2>Directives</H2> - <UL> - <LI><A HREF="#mmapfile">MMapFile</A> - </LI> - <LI><A HREF="#cachefile">CacheFile</A> - </LI> - </UL> - - <HR> - - <H2><A NAME="mmapfile">MMapFile</A></H2> - <P> - <A - HREF="directive-dict.html#Syntax" - REL="Help" - ><STRONG>Syntax:</STRONG></A> MMapFile <EM>filename</EM> [<em>filename</em>] ... - <BR> - <A - HREF="directive-dict.html#Default" - REL="Help" - ><STRONG>Default:</STRONG></A> <EM>None</EM> - <BR> - <A - HREF="directive-dict.html#Context" - REL="Help" - ><STRONG>Context:</STRONG></A> server-config - <BR> - <A - HREF="directive-dict.html#Override" - REL="Help" - ><STRONG>Override:</STRONG></A> <EM>Not applicable</EM> - <BR> - <A - HREF="directive-dict.html#Status" - REL="Help" - ><STRONG>Status:</STRONG></A> Experimental - <BR> - <A - HREF="directive-dict.html#Module" - REL="Help" - ><STRONG>Module:</STRONG></A> mod_file_cache - <BR> - <A - HREF="directive-dict.html#Compatibility" - REL="Help" - ><STRONG>Compatibility:</STRONG></A> Only in Apache 1.3 (via - mod_mmap_statis) or later. - - <P> - The <CODE>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>filename</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>mod_alias</CODE> or - <CODE>mod_rewrite</CODE>. - </P> - - Example: - - <PRE> - MMapFile /usr/local/apache/htdocs/index.html - </PRE> - -<hr> - - <H2><A NAME="cachefile">CacheFile</A></H2> - <P> - <A - HREF="directive-dict.html#Syntax" - REL="Help" - ><STRONG>Syntax:</STRONG></A> CacheFile <EM>filename</EM> [<em>filename</em>] ... - <BR> - <A - HREF="directive-dict.html#Default" - REL="Help" - ><STRONG>Default:</STRONG></A> <EM>None</EM> - <BR> - <A - HREF="directive-dict.html#Context" - REL="Help" - ><STRONG>Context:</STRONG></A> server-config - <BR> - <A - HREF="directive-dict.html#Override" - REL="Help" - ><STRONG>Override:</STRONG></A> <EM>Not applicable</EM> - <BR> - <A - HREF="directive-dict.html#Status" - REL="Help" - ><STRONG>Status:</STRONG></A> Experimental - <BR> - <A - HREF="directive-dict.html#Module" - REL="Help" - ><STRONG>Module:</STRONG></A> mod_file_cache - <BR> - <A - HREF="directive-dict.html#Compatibility" - REL="Help" - ><STRONG>Compatibility:</STRONG></A> Only available in Apache 2.0 or later. - - <P> - The <CODE>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>filename</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>mod_alias</CODE> or - <CODE>mod_rewrite</CODE>. - </P> - - Example: - - <PRE> - CacheFile /usr/local/apache/htdocs/index.html - </PRE> - - <P> - <STRONG>Note</STRONG>: 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">Include</A> directive, and consider this command: - <PRE> - find /www/htdocs -type f -print \ - | sed -e 's/.*/mmapfile &/' > /www/conf/mmap.conf - </PRE> - -<!--#include virtual="footer.html" --> - </BODY> -</HTML> |