rse 98/04/03 08:07:17
Modified: . STATUS
src CHANGES Configuration.tmpl
htdocs/manual/mod index.html directives.html
Added: htdocs/manual/mod mod_mmap_static.html
Log:
Although mod_mmap_static is an experimental module it works fine and already
is distributed with Apache it was not prepared the same way as the other
modules. Hence let us give it a first cut for a documentation and an
(disabled, of course) entry in the Configuration.tmpl file.
Dean: Feel free to fix both my english and my initial content in the
mod_mmap_static.html document. It's your baby, so you know
best what is missing.
Revision Changes Path
1.259 +1 -0 apache-1.3/STATUS
Index: STATUS
===================================================================
RCS file: /export/home/cvs/apache-1.3/STATUS,v
retrieving revision 1.258
retrieving revision 1.259
diff -u -r1.258 -r1.259
--- STATUS 1998/04/03 13:37:41 1.258
+++ STATUS 1998/04/03 16:07:10 1.259
@@ -137,6 +137,7 @@
* Martin's fix CONNECT proxy handling again
* Ralf's fallback strategy for DSO by trying to guess flags from Perl
* Ralf's add of the query (-q) option to apxs
+ * Ralf's initial doc and Configuration.tmpl entry for mod_mmap_static
Available Patches:
1.755 +6 -0 apache-1.3/src/CHANGES
Index: CHANGES
===================================================================
RCS file: /export/home/cvs/apache-1.3/src/CHANGES,v
retrieving revision 1.754
retrieving revision 1.755
diff -u -r1.754 -r1.755
--- CHANGES 1998/04/03 13:29:05 1.754
+++ CHANGES 1998/04/03 16:07:11 1.755
@@ -1,4 +1,10 @@
Changes with Apache 1.3b6
+
+ *) Add documentation file and src/Configuration.tmpl entry for the
+ experimental mod_mmap_static module. Because although it is and marked
as
+ an experimental one it is distributed and thus should be documented and
+ prepared for configuration the same way as all others modules.
+ [Ralf S. Engelschall]
*) Add query (-q) option to apxs support tool to be able to manually query
specific settings from apxs. This is needed for instance when you
1.93 +9 -0 apache-1.3/src/Configuration.tmpl
Index: Configuration.tmpl
===================================================================
RCS file: /export/home/cvs/apache-1.3/src/Configuration.tmpl,v
retrieving revision 1.92
retrieving revision 1.93
diff -u -r1.92 -r1.93
--- Configuration.tmpl 1998/04/03 13:38:35 1.92
+++ Configuration.tmpl 1998/04/03 16:07:13 1.93
@@ -347,6 +347,15 @@
# AddModule modules/standard/mod_so.o
+## mod_mmap_static lets you speedup the serving of a list of files
+## by mmap()ing them at server startup-time into memory and thus
+## avoiding a lot of I/O which is required on normal file serving.
+## This is an experimental feature. USE IT WITH CARE AND ALWAYS
+## REMMBER THAT WHENEVER ONE OF THESE FILES CHANGE THE SERVER HAS
+## TO BE RESTARTED MANUALLY TO SYNC WITH THE CHANGED FILE CONTENTS.
+
+# AddModule modules/experimental/mod_mmap_static.o
+
## mod_setenvif lets you set environment variables based on the HTTP header
## fields in the request; this is useful for conditional HTML, for example.
## Since it is also used to detect buggy browsers for workarounds, it
1.26 +2 -0 apache-1.3/htdocs/manual/mod/index.html
Index: index.html
===================================================================
RCS file: /export/home/cvs/apache-1.3/htdocs/manual/mod/index.html,v
retrieving revision 1.25
retrieving revision 1.26
diff -u -r1.25 -r1.26
--- index.html 1998/03/21 17:03:48 1.25
+++ index.html 1998/04/03 16:07:14 1.26
@@ -91,6 +91,8 @@
<DD>Determining document types using file extensions.
<DT><A HREF="mod_mime_magic.html">mod_mime_magic</A>
<DD>Determining document types using "magic numbers".
+<DT><A HREF="mod_mmap_static.html">mod_mmap_static</A>
+<DD>Mapping files into memory for faster serving.
<DT><A HREF="mod_negotiation.html">mod_negotiation</A>
<DD>Content negotiation.
<DT><A HREF="mod_proxy.html">mod_proxy</A>
1.43 +1 -0 apache-1.3/htdocs/manual/mod/directives.html
Index: directives.html
===================================================================
RCS file: /export/home/cvs/apache-1.3/htdocs/manual/mod/directives.html,v
retrieving revision 1.42
retrieving revision 1.43
diff -u -r1.42 -r1.43
--- directives.html 1998/03/21 17:03:47 1.42
+++ directives.html 1998/04/03 16:07:15 1.43
@@ -136,6 +136,7 @@
<LI><A HREF="mod_cern_meta.html#metasuffix">MetaSuffix</A>
<LI><A HREF="mod_mime_magic.html#mimemagicfile">MimeMagicFile</A>
<LI><A HREF="core.html#minspareservers">MinSpareServers</A>
+<LI><A HREF="mod_mmap_static.html#mmapfile">MMapFile</A>
<LI><A HREF="core.html#namevirtualhost">NameVirtualHost</A>
<LI><A HREF="mod_proxy.html#nocache">NoCache</A>
<LI><A HREF="core.html#options">Options</A>
1.1 apache-1.3/htdocs/manual/mod/mod_mmap_static.html
Index: mod_mmap_static.html
===================================================================
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>Apache module mod_mmap_static</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_mmap_static</H1>
<P>
This module is contained in the <CODE>mod_mmap_static.c</CODE> file, with
Apache 1.3 and later. It provides mmap()ing of a statically configured list
of frequently requested but not changed files. It is not compiled into the
server by default. To use <CODE>mod_mmap_static</CODE> you have to enable
the following line in the server build <CODE>Configuration</CODE> file:
<PRE>
AddModule modules/experimental/mod_mmap_static.o
</PRE>
</P>
<H2>Summary</H2>
<P>
This is an <STRONG>experimental</STRONG> module and should be used with
care. It maps a list of statically configured files (via
<CODE>MMapFile</CODE> directives in the main server configuration) into
memory through the system call <CODE>mmap()</CODE>. Although this system
call is not available on every platform, most of the modern Unix derivates
provide it. At least those ones conforming to the POSIX.4 definition. The
size of the mapable files usually has to be less then 2GB. But this is no
real restriction for documents on a webserver.
</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 by at least sending it a HUP or USR1 signal. 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 intend of I/O reduction.
</P>
<H2>Directives</H2>
<UL>
<LI><A HREF="#mmapfile">MMapFile</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>
<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_mmap_static
<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> Only available in Apache 1.3 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 etc. because that again would cost extra <CODE>stat()</CODE>
system calls which is not acceptable.
</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>
Example:
<PRE>
MMapFile /usr/local/apache/htdocs/index.html
</PRE>
<!--#include virtual="footer.html" -->
</BODY>
</HTML>
