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<H1 ALIGN="CENTER">Apache Core Features</h1>
These configuration parameters control the core Apache features, and are
always available.
<ul>
<li><A HREF="#accessconfig">AccessConfig</A>
<li><A HREF="#accessfilename">AccessFileName</A>
<li><A HREF="#addmodule">AddModule</A>
<li><A HREF="#allowoverride">AllowOverride</A>
<li><A HREF="#authname">AuthName</A>
<li><A HREF="#authtype">AuthType</A>
<li><A HREF="#bindaddress">BindAddress</A>
<li><A HREF="#clearmodulelist">ClearModuleList</A>
<li><A HREF="#defaulttype">DefaultType</A>
<li><A HREF="#directory">&lt;Directory&gt;</A>
<li><A HREF="#documentroot">DocumentRoot</A>
<li><A HREF="#errordocument">ErrorDocument</A>
<li><A HREF="#errorlog">ErrorLog</A>
<li><A HREF="#files">&lt;Files&gt;</A>
<li><A HREF="#group">Group</A>
<li><A HREF="#hostnamelookups">HostNameLookups</A>
<li><A HREF="#identitycheck">IdentityCheck</A>
<li><A HREF="#ifmodule">&lt;IfModule&gt;</A>
<li><A HREF="#keepalive">KeepAlive</A>
<li><A HREF="#keepalivetimeout">KeepAliveTimeout</A>
<li><A HREF="#limit">&lt;Limit&gt;</A>
<li><A HREF="#listen">Listen</A>
<li><A HREF="#location">&lt;Location&gt;</A>
<li><A HREF="#lockfile">LockFile</A>
<li><A HREF="#maxclients">MaxClients</A>
<li><A HREF="#maxkeepaliverequests">MaxKeepAliveRequests</a>
<li><A HREF="#maxrequestsperchild">MaxRequestsPerChild</A>
<li><A HREF="#maxspareservers">MaxSpareServers</A>
<li><A HREF="#minspareservers">MinSpareServers</A>
<li><A HREF="#options">Options</A>
<li><A HREF="#pidfile">PidFile</A>
<li><A HREF="#port">Port</A>
<li><A HREF="#require">require</A>
<li><A HREF="#resourceconfig">ResourceConfig</A>
<li><A HREF="#rlimitcpu">RLimitCPU</A>
<li><A HREF="#rlimitmem">RLimitMEM</A>
<li><A HREF="#rlimitnproc">RLimitNPROC</A>
<li><A HREF="#satisfy">Satisfy</A>
<li><A HREF="#scoreboardfile">ScoreBoardFile</A>
<li><A HREF="#sendbuffersize">SendBufferSize</A>
<li><A HREF="#serveradmin">ServerAdmin</A>
<li><A HREF="#serveralias">ServerAlias</A>
<li><A HREF="#servername">ServerName</A>
<li><A HREF="#serverpath">ServerPath</A>
<li><A HREF="#serverroot">ServerRoot</A>
<li><A HREF="#servertype">ServerType</A>
<li><A HREF="#startservers">StartServers</A>
<li><A HREF="#timeout">TimeOut</A>
<li><A HREF="#user">User</A>
<li><A HREF="#virtualhost">&lt;VirtualHost&gt;</A>
</ul>
<hr>
<A name="accessconfig"><h2>AccessConfig directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AccessConfig} directive&gt; -->
<strong>Syntax:</strong> AccessConfig <em>filename</em><br>
<strong>Default:</strong> <code>AccessConfig conf/access.conf</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The server will read this file for more directives after reading the
<A HREF="#resourceconfig">ResourceConfig</A> file. <em>Filename</em> is
relative to the <A HREF="#serverroot">ServerRoot</A>.
This feature can be disabled using:
<blockquote><code>AccessConfig /dev/null</code></blockquote>
Historically, this file only contained
<A HREF="#directory">&lt;Directory&gt;</A> sections; in fact it can now
contain any server directive allowed in the <em>server config</em> context.
<p><hr>
<A name="accessfilename"><h2>AccessFileName directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AccessFileName} directive&gt; -->
<strong>Syntax:</strong> AccessFileName <em>filename</em><br>
<strong>Default:</strong> <code>AccessFileName .htaccess</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
When returning a document to the client the server looks for an
access control file with this name in every directory of the path to
the document, if access control files are enabled for that directory.
For example:
<blockquote><code>AccessFileName .acl</code></blockquote>
before returning the document /usr/local/web/index.html, the
server will read /.acl, /usr/.acl, /usr/local/.acl and /usr/local/web/.acl
for directives, unless they have been disabled with
<blockquote><code>
&lt;Directory /&gt;<br>
AllowOverride None<br>
&lt;/Directory&gt;</code></blockquote><p><hr>
<A name="addmodule"><h2>AddModule directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AddModule} directive&gt; -->
<strong>Syntax:</strong> AddModule <em>module module ...</em><br>
<strong>Context:</strong> server config <br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> AddModule is only available in Apache 1.2 and later<p>
The server can have modules compiled in which are not actively in use.
This directive can be used to enable the use of those modules. The
server comes with a pre-loaded list of active modules; this list can
be cleared with the <A HREF="#clearmodulelist">ClearModuleList</A>
directive.<p><hr>
<A name="allowoverride"><h2>AllowOverride directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AllowOverride} directive&gt; -->
<strong>Syntax:</strong> AllowOverride <em>override override ...</em><br>
<strong>Default:</strong> <code>AllowOverride All</code><br>
<strong>Context:</strong> directory<br>
<strong>Status:</strong> core<p>
When the server finds an .htaccess file (as specified by
<A HREF="#accessfilename">AccessFileName</A>) it needs to know which
directives declared in that file can override earlier access information.<p>
<em>Override</em> can be set to <code>None</code>, in which case the server
will not read the file, <code>All</code> in which case the server will
allow all the directives, or one or more of the following:
<dl>
<dt>AuthConfig
<dd>
<!--%plaintext &lt;?INDEX {\tt AuthConfig} override&gt; -->
Allow use of the authorization directives
(<A HREF="mod_auth_dbm.html#authdbmgroupfile">AuthDBMGroupFile</A>,
<A HREF="mod_auth_dbm.html#authdbmuserfile">AuthDBMUserFile</A>,
<A HREF="mod_auth.html#authgroupfile">AuthGroupFile</A>,
<A HREF="#authname">AuthName</A>, <A HREF="#authtype">AuthType</A>,
<A HREF="mod_auth.html#authuserfile">AuthUserFile</A>,
<A HREF="#require">require</A>, etc.).
<dt>FileInfo
<dd>
<!--%plaintext &lt;?INDEX {\tt FileInfo} override&gt; -->
Allow use of the directives controlling document types
(<A HREF="mod_mime.html#addencoding">AddEncoding</A>,
<A HREF="mod_mime.html#addlanguage">AddLanguage</A>,
<A HREF="mod_mime.html#addtype">AddType</A>,
<A HREF="#defaulttype">DefaultType</A>,
<A HREF="#errordocument">ErrorDocument</A>,
<A HREF="mod_negotiation.html#languagepriority">LanguagePriority</A>, etc.).
<dt>Indexes
<dd>
<!--%plaintext &lt;?INDEX {\tt Indexes} override&gt; -->
Allow use of the directives controlling directory indexing
(<A HREF="mod_dir.html#adddescription">AddDescription</A>,
<A HREF="mod_dir.html#addicon">AddIcon</A>,
<A HREF="mod_dir.html#addiconbyencoding">AddIconByEncoding</A>,
<A HREF="mod_dir.html#addiconbytype">AddIconByType</A>,
<A HREF="mod_dir.html#defaulticon">DefaultIcon</A>,
<A HREF="mod_dir.html#directoryindex">DirectoryIndex</A>,
<A HREF="mod_dir.html#fancyindexing">FancyIndexing</A>,
<A HREF="mod_dir.html#headername">HeaderName</A>,
<A HREF="mod_dir.html#indexignore">IndexIgnore</A>,
<A HREF="mod_dir.html#indexoptions">IndexOptions</A>,
<A HREF="mod_dir.html#readmename">ReadmeName</A>, etc.).
<dt>Limit
<dd>
<!--%plaintext &lt;?INDEX {\tt Limit} override&gt; -->
Allow use of the directives controlling host access (allow, deny and order).
<dt>Options
<dd>
<!--%plaintext &lt;?INDEX {\tt Options} override&gt; -->
Allow use of the directives controlling specific directory features
(<A HREF="#options">Options</A> and
<A HREF="mod_include.html#xbithack">XBitHack</A>).
</dl><p><hr>
<A name="authname"><h2>AuthName directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AuthName} directive&gt; -->
<strong>Syntax:</strong> AuthName <em>auth-domain</em><br>
<strong>Context:</strong> directory, .htaccess<br>
<strong>Override:</strong> AuthConfig<br>
<strong>Status:</strong> core<p>
This directive sets the name of the authorization realm for a directory.
This realm is given to the client so that the user knows which username and
password to send.
It must be accompanied by <A HREF="#authtype">AuthType</A> and
<A HREF="#require">require</A> directives, and directives such as
<A HREF="mod_auth.html#authuserfile">AuthUserFile</A> and
<A HREF="mod_auth.html#authgroupfile">AuthGroupFile</A> to work.<p><hr>
<A name="authtype"><h2>AuthType directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt AuthType} directive&gt; -->
<strong>Syntax:</strong> AuthType <em>type</em><br>
<strong>Context:</strong> directory, .htaccess<br>
<strong>Override:</strong> AuthConfig<br>
<strong>Status:</strong> core<p>
This directive selects the type of user authentication for a directory.
Only <code>Basic</code> is currently implemented.
<!--%plaintext &lt;?INDEX {\tt Basic} authentication scheme&gt; -->
It must be accompanied by <A HREF="#authname">AuthName</A> and
<A HREF="#require">require</A> directives, and directives such as
<A HREF="mod_auth.html#authuserfile">AuthUserFile</A> and
<A HREF="mod_auth.html#authgroupfile">AuthGroupFile</A> to work.<p><hr>
<A name="bindaddress"><h2>BindAddress directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt BindAddress} directive&gt; -->
<strong>Syntax:</strong> BindAddress <em>saddr</em><br>
<strong>Default:</strong> <code>BindAddress *</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
A Unix&#174; http server can either listen for connections to every
IP address of the server machine, or just one IP address of the server
machine. <em>Saddr</em> can be
<menu>
<li>*
<li>An IP address
<li>A fully-qualified Internet domain name
</menu>
If the value is *, then the server will listen for connections on
every IP address, otherwise it will only listen on the IP address
specified. <p>
This option can be used as an alternative method for supporting
<A HREF="../virtual-host.html">virtual hosts</A> instead of using
<A HREF="#virtualhost">&lt;VirtualHost&gt;</A> sections.
<p><strong>See Also:</strong>
<a href="../dns-caveats.html">DNS Issues</a><br>
<strong>See Also:</strong>
<a href="../bind.html">Setting which addresses and ports Apache uses</a></p>
<hr>
<A name="clearmodulelist"><h2>ClearModuleList directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ClearModuleList} directive&gt; -->
<strong>Syntax:</strong> ClearModuleList<br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> ClearModuleList is only available in Apache 1.2 and later<p>
The server comes with a built-in list of active modules. This
directive clears the list. It is assumed that the list will then be
re-populated using the <A HREF="#addmodule">AddModule</A> directive.<p><hr>
<A name="defaulttype"><h2>DefaultType directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt DefaultType} directive&gt; -->
<strong>Syntax:</strong> DefaultType <em>mime-type</em><br>
<strong>Default:</strong> <code>DefaultType text/html</code><br>
<strong>Context:</strong> server config, virtual host, directory, .htaccess<br>
<strong>Override:</strong> FileInfo<br>
<strong>Status:</strong> core<p>
There will be times when the server is asked to provide a document
whose type cannot be determined by its MIME types mappings.<p>
The server must inform the client of the content-type of the document, so in
the event of an unknown type it uses the <CODE>DefaultType</CODE>. For
example:
<blockquote><code>DefaultType image/gif</code></blockquote>
would be appropriate for a directory which contained many gif images
with filenames missing the .gif extension.<p><hr>
<A name="directory"><h2>&lt;Directory&gt; directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt Directory} section directive&gt; -->
<strong>Syntax:</strong> &lt;Directory <em>directory</em>&gt; ... &lt;/Directory&gt; <br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> Core. <p>
&lt;Directory&gt; and &lt;/Directory&gt; are used to enclose a group of
directives which will apply only to the named directory and sub-directories
of that directory. Any directive which is allowed in a directory
context may be used. <em>Directory</em> is either the full path to a directory,
or a wild-card string. In a wild-card string, `?' matches any single character,
and `*' matches any sequences of characters. Example:
<pre>
&lt;Directory /usr/local/httpd/htdocs&gt;
Options Indexes FollowSymLinks
&lt;/Directory&gt;
</pre>
<p><strong>Apache 1.2 and above:</strong>
Extended regular expressions can also be used, with the addition of the
<code>~</code> character. For example:</p>
<pre>
&lt;Directory ~ &quot;^/www/.*/[0-9]{3}&quot;&gt;
</pre>
would match directories in /www/ that consisted of three numbers.<p>
<p>If multiple directory sections match the directory (or its parents) containing
a document, then the directives are applied in the order of shortest match
first, interspersed with the directives from the
<A HREF="#accessfilename">.htaccess</A> files. For example, with
<blockquote><code>
&lt;Directory /&gt;<br>
AllowOverride None<br>
&lt;/Directory&gt;<br><br>
&lt;Directory /home/*&gt;<br>
AllowOverride FileInfo<br>
&lt;/Directory&gt;</code></blockquote>
for access to the document <code>/home/web/dir/doc.html</code> the
steps are:
<menu>
<li>Apply directive <code>AllowOverride None</code> (disabling
<code>.htaccess</code> files).
<li>Apply directive <code>AllowOverride FileInfo</code> (for directory
<code>/home/web</code>).
<li>Apply any FileInfo directives in <code>/home/web/.htaccess</code>
</menu>
<P>
<STRONG>
Note that the default Apache access for &lt;Directory /&gt; is
<SAMP>Allow from All</SAMP>. This means that Apache will serve any file
mapped from an URL. It is recommended that you change this with a block
such as
</STRONG>
<PRE>
&lt;Directory /&gt;
Order Deny,Allow
Deny from All
&lt;/Directory&gt;
</PRE>
<P>
<STRONG>
and then override this for directories you <EM>want</EM> accessible.
See the
<A
HREF="../misc/security_tips.html"
>Security Tips</A>
page for more details.
</STRONG>
</P>
The directory sections typically occur in the access.conf file, but they
may appear in any configuration file. &lt;Directory&gt; directives cannot
nest, and cannot appear in a <A HREF="#limit">&lt;Limit&gt;</A> section.
<p><hr>
<A NAME="documentroot"><h2>DocumentRoot directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt DocumentRoot} directive&gt; -->
<strong>Syntax:</strong> DocumentRoot <em>directory-filename</em><br>
<strong>Default:</strong> <code>DocumentRoot
/usr/local/etc/httpd/htdocs</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
This directive sets the directory from which httpd will serve files.
Unless matched by a directive like Alias, the server appends the path
from the requested URL to the document root to make the path to the
document. Example:
<blockquote><code>DocumentRoot /usr/web</code></blockquote>
then an access to <code>http://www.my.host.com/index.html</code> refers
to <code>/usr/web/index.html</code>.
<P>There appears to be a bug in mod_dir which causes problems when the
DocumentRoot has a trailing slash (i.e. "DocumentRoot /usr/web/") so
please avoid that.
<p><hr>
<A name="errordocument"><h2>ErrorDocument directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ErrorDocument} directive&gt; -->
<strong>Syntax:</strong> ErrorDocument <em>error-code document</em><br>
<strong>Context</strong> server config, virtual host, directory, .htaccess<br>
<strong>Status:</strong> core<br>
<strong>Override:</strong> FileInfo<br>
<strong>Compatibility:</strong> The directory and .htaccess contexts
are only available in Apache 1.1 and later.<p>
In the event of a problem or error, Apache can be configured to do
one of four things,
<OL>
<LI>output a simple hardcoded error message
<LI>output a customized message
<LI>redirect to a local URL to handle the problem/error
<LI>redirect to an external URL to handle the problem/error
</OL>
<P>The first option is the default, while options 2-4 are configured
using the <CODE>ErrorDocument</CODE> directive, which is followed by
the HTTP response code and a message or URL.
<P><em>Messages</em> in this context begin with a single quote
(<code>"</code>), which does not form part of the message itself.
Apache will sometimes offer additional information regarding the
problem/error.
<P>URLs can begin with a slash (/) for local URLs, or be a full
URL which the client can resolve. Examples:
<blockquote><code>
ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br>
ErrorDocument 404 /cgi-bin/bad_urls.pl<br>
ErrorDocument 401 /subscription_info.html<br>
ErrorDocument 403 "Sorry can't allow you access today
</code></blockquote>
<P>Note that when you specify an <CODE>ErrorDocument</CODE> that
points to a remote URL (ie. anything with a method such as "http" in
front of it) Apache will send a redirect to the client to tell it
where to find the document, even if the document ends up being
on the same server.. This has several implications, the
most important being that <STRONG>if you use an "ErrorDocument 401"
directive then it must refer to a local document.</STRONG> This results
from the nature of the HTTP basic authentication scheme.
<P>See Also: <A HREF="../custom-error.html">documentation of customizable
responses.</A><p><hr>
<A name="errorlog"><h2>ErrorLog directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ErrorLog} directive&gt; -->
<strong>Syntax:</strong> ErrorLog <em>filename</em><br>
<strong>Default:</strong> <code>ErrorLog logs/error_log</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The error log directive sets the name of the file to which the server will log
any errors it encounters. If the filename does not begin with a slash (/)
then it is assumed to be relative to the <A HREF="#serverroot">ServerRoot</A>.
Example:
<blockquote><code>ErrorLog /dev/null</code></blockquote>
This effectively turns off error logging.<p>
SECURITY: See the <A HREF="../misc/security_tips.html">security tips</A>
document for details on why your security could be compromised if
the directory where logfiles are stored is writable by anyone other
than the user that starts the server.
<p><hr>
<A name="files"><h2>&lt;Files&gt;</h2></A>
<strong>Syntax:</strong> &lt;Files <em>filename</em>&gt;
... &lt;/Files&gt;<br>
<strong>Context:</strong> server config, virtual host, htaccess<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> only available in Apache
1.2 and above.<p>
<p>The &lt;Files&gt; directive provides for access control by
filename. It is comparable to the <a
href="#directory">&lt;Directory&gt;</a> directive and
<a href="#location">&lt;Location&gt;</a> directives. It
should be matched with a &lt;/Files&gt; directive. Directives that
apply to the filename given should be listed
within. <code>&lt;Files&gt;</code> sections are processed in the
order they appear in the configuration file, after the
&lt;Directory&gt; sections and <code>.htaccess</code> files are
read, but before &lt;Location&gt; sections.</p>
<p>The <em>filename</em> argument should include a filename, or a
wild-card string, where `?' matches any single character, and `*' matches any
sequences of characters. Extended regular expressions can also be used, with the addition of
the <code>~</code> character. For example:</p>
<pre>
&lt;Files ~ &quot;\.(gif|jpe?g|png)$&quot;&gt;
</pre>
would match most common Internet graphics formats.
<p>Note that unlike <a
href="#directory"><code>&lt;Directory&gt;</code></a> and <a
href="#location"><code>&lt;Location&gt;</code></a> sections,
<code>&lt;Files&gt;</code> sections can be used inside .htaccess
files. This allows users to control access to their own files, at a
file-by-file level. When used in an .htaccess file, if the
<em>filename</em> does not begin with a <code>/</code> character,
the directory being applied will be prefixed automatically.
<p> <hr>
<A name="group"><h2>Group directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt Group} directive&gt; -->
<strong>Syntax:</strong> Group <em>unix-group</em><br>
<strong>Default:</strong> <code>Group #-1</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The Group directive sets the group under which the server will answer requests.
In order to use this directive, the stand-alone server must be run initially
as root. <em>Unix-group</em> is one of:
<dl>
<dt>A group name
<dd>Refers to the given group by name.
<dt># followed by a group number.
<dd>Refers to a group by its number.
</dl>
It is recommended that you set up a new group specifically for running the
server. Some admins use user <code>nobody</code>, but this is not always
possible or desirable.<p>
Note: if you start the server as a non-root user, it will fail to change
to the specified group, and will instead continue to run as the group of the
original user. <p>
Special note: Use of this directive in &lt;VirtualHost&gt; requires a
properly configured <A HREF="../suexec.html">suEXEC wrapper</A>.
When used inside a &lt;VirtualHost&gt; in this manner, only the group
that CGIs are run as is affected. Non-CGI requests are still processed
as the group specified in the main Group directive.<p>
SECURITY: See <A HREF="#user">User</A> for a discussion of the security
considerations.<p><hr>
<A name="hostnamelookups"><h2>HostNameLookups directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt HostNameLookups} directive&gt; -->
<strong>Syntax:</strong> HostNameLookups <em>boolean</em><br>
<strong>Default:</strong> <code>HostNameLookups on</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
This directive enables DNS lookups so that host names can be logged.
Having this directive set <code>on</code> also enables the use of names
in &lt;Limit&gt; blocks for access control.<p>
Heavily loaded sites should set this directive <code>off</code>, since DNS
lookups can take considerable amounts of time. The utility <i>logresolve</i>,
provided in the <i>/support</i> directory, can be used to look up host names
from logged IP addresses offline.<p><hr>
<A name="identitycheck"><h2>IdentityCheck directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt IdentityCheck} directive&gt; -->
<strong>Syntax:</strong> IdentityCheck <em>boolean</em><br>
<strong>Default:</strong> <code>IdentityCheck off</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
This directive enables RFC1413-compliant logging of the remote user name
for each connection, where the client machine runs identd or something similar.
This information is logged in the access log. <em>Boolean</em> is either
<code>on</code> or <code>off</code>.<p>
The information should not be trusted in any way except for rudimentary usage
tracking.<p>
Note that this can cause serious latency problems accessing your server
since every request requires one of these lookups to be performed. When
firewalls are involved each lookup might possibly fail and add 30 seconds
of latency to each hit. So in general this is not very useful on public
servers accessible from the Internet.
<p><hr>
<A NAME="ifmodule"><H2>&lt;IfModule&gt;</H2></A>
<b>Syntax:</b> &lt;IfModule [!]<i>module-name</i>&gt; <i>...</i>
&lt;/IfModule&gt;<br>
<b>Default:</b> None<br>
<b>Context:</b> all<br>
<b>Status:</b> Core
<strong>Compatibility:</strong> ScriptLog is only available in 1.2 and
later.<P>
<p>
The &lt;IfModule <i>test</i>&gt;...&lt;/IfModule&gt;
section is used to mark directives that are conditional. The
directives within an IfModule section are only
processed if the <i>test</i> is true. If <i>test</i>
is false, everything between the start and end markers
is ignored.<p>
The <i>test</i> in the &lt;IfModule&gt; section directive
can be one of two forms:
<ul>
<li><i>module name</i>
<li>!<i>module name</i>
</ul>
<p>In the former case, the directives between the start and end markers
are only processed if the module named <i>module name</i> is compiled
in to Apache. The second format reverses the test, and only processes
the directives if <i>module name</i> is <b>not</b> compiled in.
<p>The <i>module name</i> argument is a module name as given as the file
name of the module, at the time it was compiled. For example,
<code>mod_rewrite.c</code>.
<p>&lt;IfModule&gt; sections are nest-able, which can be used to implement
simple multiple-module tests.
<P> <hr>
<h2><a name="keepalive">KeepAlive</a></h2>
<strong>Syntax: (Apache 1.1)</strong> KeepAlive <em>max-requests</em><br>
<strong>Default: (Apache 1.1)</strong> <code>KeepAlive 5</code><br>
<strong>Syntax: (Apache 1.2)</strong> KeepAlive <em>on/off</em><br>
<strong>Default: (Apache 1.2)</strong> <code>KeepAlive On</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> Core<br>
<strong>Compatibility:</strong> KeepAlive is only available in Apache
1.1 and later.<p>
This directive enables
<a href="../keepalive.html">Keep-Alive</a>
support.
<p><strong>Apache 1.1</strong>: Set <em>max-requests</em>
to the maximum number of requests you want Apache to entertain per
request. A limit is imposed to prevent a client from hogging your
server resources. Set this to <code>0</code> to disable support.
<p><strong>Apache 1.2 and later</strong>: Set to "On" to enable
persistent connections, "Off" to disable. See also the <a
href="#maxkeepaliverequests">MaxKeepAliveRequests</a> directive.</p>
<h2><a name="keepalivetimeout">KeepAliveTimeout</a></h2>
<strong>Syntax:</strong> KeepAliveTimeout <em>seconds</em><br>
<strong>Default:</strong> <code>KeepAliveTimeout 15</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> Core<br>
<strong>Compatibility:</strong> KeepAliveTimeout is only available in Apache
1.1 and later.<p>
The number of seconds Apache will wait for a subsequent request before
closing the connection. Once a request has been received, the timeout
value specified by the <a
href="#timeout"><code>Timeout</code></a> directive
applies.
<hr>
<A name="listen"><h2>Listen</h2></A>
<strong>Syntax:</strong>
Listen [<em>IP address</em>:]<em>port number</em><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> Listen is only available in Apache
1.1 and later.<p>
<p>The Listen directive instructs Apache to listen to more than one IP
address or port; by default it responds to requests on all IP
interfaces, but only on the port given by the <a href="#port">Port</a>
directive.</p>
<p><strong>See Also:</strong>
<a href="../dns-caveats.html">DNS Issues</a><br>
<strong>See Also:</strong>
<a href="../bind.html">Setting which addresses and ports Apache uses</a><br>
<strong>See Also:</strong>
<a href="../misc/known_bugs.html#listenbug">Known Bugs</a></p>
<hr>
<A name="limit"><h2>&lt;Limit&gt; directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt Limit} section directive&gt; -->
<strong>Syntax:</strong>
&lt;Limit <em>method method</em> ... &gt; ... &lt;/Limit&gt;<br>
<strong>Context:</strong> any<br>
<strong>Status:</strong> core<p>
&lt;Limit&gt; and &lt;/Limit&gt; are used to enclose a group of
access control directives which will then apply only to the specified
access methods, where <em>method</em> is any valid HTTP method.
Any directive except another &lt;Limit&gt; or
<A HREF="#directory">&lt;Directory&gt;</A> may be used; the majority will be
unaffected by the &lt;Limit&gt;. Example:
<blockquote><code>
&lt;Limit GET POST&gt;<br>
require valid-user<br>
&lt;/Limit&gt;</code></blockquote>
If an access control directive appears outside a &lt;Limit&gt; directive,
then it applies to all access methods.<p><hr>
<h2><a name="location">&lt;Location&gt;</a></h2>
<strong>Syntax:</strong> &lt;Location <em>URL</em>&gt;
... &lt;/Location&gt;<br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> Location is only available in Apache
1.1 and later.<p>
<p>The &lt;Location&gt; directive provides for access control by
URL. It is comparable to the <a
href="#directory">&lt;Directory&gt;</a> directive, and
should be matched with a &lt;/Location&gt; directive. Directives that
apply to the URL given should be listed
within. <code>&lt;Location&gt;</code> sections are processed in the
order they appear in the configuration file, after the
&lt;Directory&gt; sections and <code>.htaccess</code> files are
read.</p>
<p>Note that, due to the way HTTP functions, <em>URL prefix</em>
should, save for proxy requests, be of the form <code>/path/</code>,
and should not include the <code>http://servername</code>. It doesn't
necessarily have to protect a directory (it can be an individual
file, or a number of files), and can include wild-cards. In a wild-card
string, `?' matches any single character, and `*' matches any
sequences of characters.
<p><strong>Apache 1.2 and above:</strong>
Extended regular expressions can also be used, with the addition of
the
<code>~</code> character. For example:</p>
<pre>
&lt;Location ~ &quot;/(extra|special)/data&quot;&gt;
</pre>
<p>would match URLs that contained the substring "/extra/data" or
"/special/data".</p>
<p>The <code>Location</code> functionality is especially useful when
combined with the <code><a
href="mod_mime.html#sethandler">SetHandler</a></code> directive. For example, to enable status requests, but allow them only
from browsers at foo.com, you might use:
<pre>
&lt;Location /status&gt;
SetHandler server-status
order deny,allow
deny from all
allow from .foo.com
&lt;/Location&gt;
</pre>
<hr>
<A NAME="lockfile"><H2>LockFile</H2></A>
<strong>Syntax:</strong> LockFile <em>filename</em><BR>
<strong>Default:</strong> <code>LockFile logs/accept.lock</code><BR>
<strong>Context:</strong> server config<BR>
<strong>Status:</strong> core<P>
The LockFile directive sets the path to the lockfile used when
Apache is compiled with either USE_FCNTL_SERIALIZED_ACCEPT or
USE_FLOCK_SERIALIZED_ACCEPT. This directive should normally be
left at its default value. The main reason for changing it is if
the <code>logs</code> directory is NFS mounted, since the lockfile
should be stored on a local disk if possible. The PID of the main
server process is automatically appended to the filename.
<P><HR>
<A name="maxclients"><h2>MaxClients</h2></A>
<!--%plaintext &lt;?INDEX {\tt MaxClients} directive&gt; -->
<strong>Syntax:</strong> MaxClients <em>number</em><br>
<strong>Default:</strong> <code>MaxClients 256</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The MaxClients directive sets the limit on the number of simultaneous
requests that can be supported; not more than this number of child server
processes will be created.<p><hr>
<A name="maxkeepaliverequests"><h2>MaxKeepAliveRequests</h2></A>
<strong>Syntax:</strong> MaxKeepAliveRequests <em>number</em><br>
<strong>Default:</strong> <code>MaxKeepAliveRequests 100</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> Only available in Apache
1.2 and later.
<p>The MaxKeepAliveRequests directive limits the number of requests
allowed per connection when <a href="#keepalive">KeepAlive</a> is
on. If it is set to "<code>0</code>", unlimited requests will be
allowed. We recommend that this setting be kept to a high value for
maximum server performance.
<A name="maxrequestsperchild"><h2>MaxRequestsPerChild directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt MaxRequestsPerChild} directive&gt; -->
<strong>Syntax:</strong> MaxRequestsPerChild <em>number</em><br>
<strong>Default:</strong> <code>MaxRequestsPerChild 0</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The MaxRequestsPerChild directive sets the limit on the number of requests
that an individual child server process will handle. After MaxRequestsPerChild
requests, the child process will die. If MaxRequestsPerChild is 0, then
the process will never expire.<p>
Setting MaxRequestsPerChild to a non-zero limit has two beneficial effects:
<ul>
<li>it limits the amount of memory that process can consume by (accidental)
memory leakage;
<li> by giving processes a finite lifetime, it helps reduce the
number of processes when the server load reduces.
</ul><p><hr>
<A name="maxspareservers"><h2>MaxSpareServers directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt MaxSpareServers} directive&gt; -->
<strong>Syntax:</strong> MaxSpareServers <em>number</em><br>
<strong>Default:</strong> <code>MaxSpareServers 10</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The MaxSpareServers directive sets the desired maximum number of <em>idle</em>
child server processes. An idle process is one which is not handling
a request. If there are more than MaxSpareServers idle, then the parent
process will kill off the excess processes.<p>
Tuning of this parameter should only be necessary on very busy sites.
Setting this parameter to a large number is almost always a bad idea.<p>
See also <A HREF="#minspareservers">MinSpareServers</A> and
<A HREF="#startservers">StartServers</A>.<p><hr>
<A name="minspareservers"><h2>MinSpareServers directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt MinSpareServers} directive&gt; -->
<strong>Syntax:</strong> MinSpareServers <em>number</em><br>
<strong>Default:</strong> <code>MinSpareServers 5</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The MinSpareServers directive sets the desired minimum number of <em>idle</em>
child server processes. An idle process is one which is not handling
a request. If there are fewer than MinSpareServers idle, then the parent
process creates new children at a maximum rate of 1 per second.<p>
Tuning of this parameter should only be necessary on very busy sites.
Setting this parameter to a large number is almost always a bad idea.<p>
See also <A HREF="#maxspareservers">MaxSpareServers</A> and
<A HREF="#startservers">StartServers</A>.<p><hr>
<A name="options"><h2>Options directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt Options} directive&gt; -->
<strong>Syntax:</strong> Options <em>[+|-]option [+|-]option ...</em><br>
<strong>Context:</strong> server config, virtual host, directory, .htaccess<br>
<strong>Override:</strong> Options<br>
<strong>Status:</strong> core<p>
The Options directive controls which server features are available in
a particular directory.
<p>
<em>option</em> can be set to <code>None</code>, in which case none of
the extra features are enabled, or one or more of the following:
<dl>
<dt>All
<dd>All options except for MultiViews.
<dt>ExecCGI
<dd>
<!--%plaintext &lt;?INDEX {\tt ExecCGI} option&gt; -->
Execution of CGI scripts is permitted.
<dt>FollowSymLinks
<dd>
<!--%plaintext &lt;?INDEX {\tt FollowSymLinks} option&gt; -->
The server will follow symbolic links in this directory.
<b>Note</b>: even though the server follows the symlink it does <i>not</i>
change the pathname used to match against <code>&lt;Directory&gt;</code>
sections.
<dt>Includes
<dd>
<!--%plaintext &lt;?INDEX {\tt Includes} option&gt; -->
Server-side includes are permitted.
<dt>IncludesNOEXEC
<dd>
<!--%plaintext &lt;?INDEX {\tt IncludesNOEXEC} option&gt; -->
Server-side includes are permitted, but the #exec command and
#include of CGI scripts are disabled.
<dt>Indexes
<dd>
<!--%plaintext &lt;?INDEX {\tt Indexes} option&gt; -->
If a URL which maps to a directory is requested, and the there is no
DirectoryIndex (e.g. index.html) in that directory, then the server will
return a formatted listing of the directory.
<dt>MultiViews
<dd>
<!--%plaintext &lt;?INDEX {\tt MultiViews} option&gt; -->
<A HREF="../content-negotiation.html">Content negotiated</A> MultiViews are
allowed.
<dt>SymLinksIfOwnerMatch
<dd>
<!--%plaintext &lt;?INDEX {\tt SymLinksIfOwnerMatch} option&gt; -->
The server will only follow symbolic links for which the target
file or directory is owned by the same user id as the link.
</dl>
Normally, if multiple <code>Options</code> could apply to a directory,
then the most specific one is taken complete; the options are not
merged. However if <i>all</i> the options on the <code>Options</code>
directive are preceded by a + or - symbol, the options are
merged. Any options preceded by a + are added to the options
currently in force, and any options preceded by a - are removed from
the options currently in force. <P>
For example, without any + and - symbols:
<blockquote><code>
&lt;Directory /web/docs&gt; <br>
Options Indexes FollowSymLinks<br>
&lt;/Directory&gt;<br>
&lt;Directory /web/docs/spec&gt; <br>
Options Includes<br>
&lt;/Directory&gt;
</code></blockquote>
then only <code>Includes</code> will be set for the /web/docs/spec
directory. However if the second <code>Options</code> directive uses the +
and - symbols:<p>
<blockquote><code>
&lt;Directory /web/docs&gt; <br>
Options Indexes FollowSymLinks<br>
&lt;/Directory&gt;<br>
&lt;Directory /web/docs/spec&gt; <br>
Options +Includes -Indexes<br>
&lt;/Directory&gt;
</code></blockquote>
then the options <code>FollowSymLinks</code> and <code>Includes</code>
are set for the /web/docs/spec directory.
<hr>
<A name="pidfile"><h2>PidFile directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt PidFile} directive&gt; -->
<strong>Syntax:</strong> PidFile <em>filename</em><br>
<strong>Default:</strong> <code>PidFile logs/httpd.pid</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The PidFile directive sets the file to which the server records the
process id of the daemon. If the filename does not begin with a slash (/)
then it is assumed to be relative to the <A HREF="#serverroot">ServerRoot</A>.
The PidFile is only used in <A HREF="#servertype">standalone</A> mode.<p>
It is often useful to be able to send the server a signal, so that it closes
and then reopens its <A HREF="#errorlog">ErrorLog</A> and TransferLog, and
re-reads its configuration files. This is done by sending a SIGHUP (kill -1)
signal to the process id listed in the PidFile.<p>
The PidFile is subject to the same warnings about log file placement and
<a href="../misc/security_tips.html">security</a>.
<p><hr>
<A name="port"><h2>Port directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt Port} directive&gt; -->
<strong>Syntax:</strong> Port <em>number</em><br>
<strong>Default:</strong> <code>Port 80</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
<em>Number</em> is a number from 0 to 65535; some port numbers (especially below
1024) are reserved for particular protocols. See <code>/etc/services</code>
for a list of some defined ports; the standard port for the http protocol
is 80.<p>
The Port directive has two behaviors, the first of which is necessary for
NCSA backwards compatibility (and which is confusing in the context of
Apache).<p>
<ul>
<li>
In the absence of any <a href="#listen">Listen</a> or
<a href="#bindaddress">BindAddress</a> directives specifying a port number,
the Port directive sets the network port on which the server listens.
If there are any Listen or BindAddress directives specifying
<code>:number</code> then Port has no effect on what address the server
listens at.
<li>The Port directive
sets the <code>SERVER_PORT</code> environment variable (for
<a href="mod_cgi.html">CGI</a> and <a href="mod_include.html">SSI</a>),
and is used when the server must generate a URL that refers to itself
(for example when creating an external redirect to itself).
</ul>
In no event does a Port setting affect
what ports a <a href="#virtualhost">VirtualHost</a> responds on, the
VirtualHost directive itself is used for that.<p>
The primary behaviour of Port should be considered to be similar to that of
the <a href="#servername">ServerName</a> directive. The ServerName
and Port together specify what you consider to be the <i>canonical</i>
address of the server.<p>
Port 80 is one of Unix's special ports. All ports numbered
below 1024 are reserved for system use, i.e. regular (non-root) users cannot
make use of them; instead they can only use higher port numbers.
To use port 80, you must start the server from the root account.
After binding to the port and before accepting requests, Apache will change
to a low privileged user as set by the <A HREF="#user">User directive</A>.<p>
If you cannot use port 80, choose any other unused port. Non-root users
will have to choose a port number higher than 1023, such as 8000.<p>
SECURITY: if you do start the server as root, be sure
not to set <A HREF="#user">User</A> to root. If you run the server as
root whilst handling connections, your site may be open to a major security
attack.<p><hr>
<A name="require"><h2>require directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt require} directive&gt; -->
<strong>Syntax:</strong> require <em>entity-name entity entity...</em><br>
<strong>Context:</strong> directory, .htaccess<br>
<strong>Override:</strong> AuthConfig<br>
<strong>Status:</strong> core<p>
This directive selects which authenticated users can access a directory.
The allowed syntaxes are:
<ul>
<li>require user <em>userid userid ...</em><p>
Only the named users can access the directory.<p>
<li>require group <em>group-name group-name ...</em><p>
Only users in the named groups can access the directory.<p>
<li>require valid-user<p>
All valid users can access the directory.
</ul>
<p>
If <code>require</code> appears in a <A HREF="#limit">&lt;Limit&gt;</A>
section, then it restricts access to the named methods, otherwise
it restricts access for all methods. Example:
<blockquote><code>
AuthType Basic<br>
AuthName somedomain<br>
AuthUserFile /web/users<br>
AuthGroupFile /web/groups<br>
&lt;Limit GET POST&gt;<br>
require group admin<br>
&lt;/Limit&gt;
</code></blockquote>
Require must be accompanied by <A HREF="#authname">AuthName</A> and
<A HREF="#authtype">AuthType</A> directives, and directives such as
<A HREF="mod_auth.html#authuserfile">AuthUserFile</A> and
<A HREF="mod_auth.html#authgroupfile">AuthGroupFile</A> (to define users and
groups) in order to work correctly.<p><hr>
<A name="resourceconfig"><h2>ResourceConfig directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ResourceConfig} directive&gt; -->
<strong>Syntax:</strong> ResourceConfig <em>filename</em><br>
<strong>Default:</strong> <code>ResourceConfig conf/srm.conf</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The server will read this file for more directives after reading the
httpd.conf file. <em>Filename</em> is relative to the
<A HREF="#serverroot">ServerRoot</A>.
This feature can be disabled using:
<blockquote><code>ResourceConfig /dev/null</code></blockquote>
Historically, this file contained most directives except for server
configuration directives and <A HREF="#directory">&lt;Directory&gt;</A>
sections; in fact it can now contain any server directive allowed in the
<em>server config</em> context.<p>
See also <A HREF="#accessconfig">AccessConfig</A>.<p><hr>
<A name="rlimit"> </A>
<A name="rlimitcpu"><h2>RLimitCPU directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt RLimitCPU} directive&gt; -->
<strong>Syntax:</strong> RLimitCPU <em># or 'max'</em> <em>[# or 'max']</em><br>
<strong>Default:</strong> <code>Unset uses operating system defaults</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> RLimitCPU is only available in Apache 1.2 and later<p>
Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all
processes and the second parameter sets the maximum resource limit. Either parameter
can be a number, or <em>max</em> to indicate to the server that the limit should
be set to the maximum allowed by the operating system configuration. Raising the
maximum resource limit requires that the server is running as root, or in the initial
startup phase.<p>
CPU resource limits are expressed in seconds per process.<p>
See also <A HREF="#rlimitmem">RLimitMEM</A> or <A HREF="#rlimitnproc">RLimitNPROC</A>.<p><hr>
<A name="rlimitmem"><h2>RLimitMEM directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt RLimitMEM} directive&gt; -->
<strong>Syntax:</strong> RLimitMEM <em># or 'max'</em> <em>[# or 'max']</em><br>
<strong>Default:</strong> <code>Unset uses operating system defaults</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> RLimitMEM is only available in Apache 1.2 and later<p>
Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all
processes and the second parameter sets the maximum resource limit. Either parameter
can be a number, or <em>max</em> to indicate to the server that the limit should
be set to the maximum allowed by the operating system configuration. Raising the
maximum resource limit requires that the server is running as root, or in the initial
startup phase.<p>
Memory resource limits are expressed in bytes per process.<p>
See also <A HREF="#rlimitcpu">RLimitCPU</A> or <A HREF="#rlimitnproc">RLimitNPROC</A>.<p><hr>
<A name="rlimitnproc"><h2>RLimitNPROC directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt RLimitNPROC} directive&gt; -->
<strong>Syntax:</strong> RLimitNPROC <em># or 'max'</em> <em>[# or 'max']</em><br>
<strong>Default:</strong> <code>Unset uses operating system defaults</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> RLimitNPROC is only available in Apache 1.2 and later<p>
Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all
processes and the second parameter sets the maximum resource limit. Either parameter
can be a number, or <em>max</em> to indicate to the server that the limit should
be set to the maximum allowed by the operating system configuration. Raising the
maximum resource limit requires that the server is running as root, or in the initial
startup phase.<p>
Process limits control the number of processes per user.<p>
Note: If CGI processes are <b>not</b> running under userids other than the
web server userid, this directive will limit the number of processes that the
server itself can create. Evidence of this situation will be indicated by
<b><em>cannot fork</em></b> messages in the error_log.<p>
See also <A HREF="#rlimitmem">RLimitMEM</A> or <A HREF="#rlimitcpu">RLimitCPU</A>.
<p><hr>
<A name="satisfy"><h2>Satisfy</h2></A>
<!--%plaintext &lt;?INDEX {\tt Satisfy} directive&gt; -->
<strong>Syntax:</strong> Satisfy <em>'any' or 'all'</em><br>
<strong>Default:</strong> Satisfy all<br>
<strong>Context:</strong> directory, .htaccess<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> Satisfy is only available in Apache 1.2 and later<p>
Access policy if both allow and require used. The parameter can be
either <em>'all'</em> or <em>'any'</em>. This directive is only useful
if access to a particular area is being restricted by both
username/password <i>and</i> client host address. In this case the
default behavior ("all") is to require that the client passes the
address access restriction <i>and</i> enters a valid username and
password. With the "any" option the client will be granted access if
they either pass the host restriction or enter a valid username and
password. This can be used to password restrict an area, but to let
clients from particular addresses in without prompting for a password.
<p><hr>
<A name="scoreboardfile"><h2>ScoreBoardFile directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ScoreBoardFile} directive&gt; -->
<strong>Syntax:</strong> ScoreBoardFile <em>filename</em><br>
<strong>Default:</strong> <code>ScoreBoardFile logs/apache_status</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The ScoreBoardFile directive is required on some architectures to place
a file that the server will use to communicate between its children and
the parent. The easiest way to find out if your architecture requires
a scoreboard file is to run Apache and see if it creates the file named
by the directive. If your architecture requires it then you must ensure
that this file is not used at the same time by more than one invocation
of Apache.<p>
If you have to use a ScoreBoardFile then you may see improved speed by
placing it on a RAM disk. But be careful that you heed the same warnings
about log file placement and
<a href="../misc/security_tips.html">security</a>.<p>
Apache 1.2 and above:<p>
Linux 1.x users might be able to add <code>-DHAVE_SHMGET</code> to
the <code>EXTRA_CFLAGS</code> in your <code>Configuration</code>. This
might work with some 1.x installations, but won't work with all of
them.<p>
SVR4 users should consider adding <code>-DHAVE_SHMGET</code> to the
<code>EXTRA_CFLAGS</code> in your <code>Configuration</code>. This
is believed to work, but we were unable to test it in time for 1.2
release.<p>
<strong>See Also</strong>:
<a href="../stopping.html">Stopping and Restarting Apache</a></p>
<p><hr>
<A name="sendbuffersize"><h2>SendBufferSize directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt SendBufferSize} directive&gt; -->
<strong>Syntax:</strong> SendBufferSize <em>bytes</em><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The server will set the TCP buffer size to the number of bytes
specified. Very useful to increase past standard OS defaults on high
speed high latency (i.e. 100ms or so, such as transcontinental
fast pipes)
<p><hr>
<A name="serveradmin"><h2>ServerAdmin directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ServerAdmin} directive&gt; -->
<strong>Syntax:</strong> ServerAdmin <em>email-address</em><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The ServerAdmin sets the e-mail address that the server includes in any
error messages it returns to the client.<p>
It may be worth setting up a dedicated address for this, e.g.
<blockquote><code>ServerAdmin www-admin@foo.bar.com</code></blockquote>
as users do not always mention that they are talking about the server!<p><hr>
<A name="serveralias"><h2>ServerAlias directive</h2></A>
<strong>Syntax:</strong> ServerAlias <em>host1 host2 ...</em><br>
<strong>Context:</strong> virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> ServerAlias is only available in Apache
1.1 and later.<p>
The ServerAlias directive sets the alternate names for a host, for use
with
<a href="../host.html">Host-header based virtual hosts</a>.
<p><strong>See Also</strong>:
<a href="../vhosts-in-depth.html">In-depth description of Virtual Host matching</a></p>
<hr>
<A name="servername"><h2>ServerName directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ServerName} directive&gt; -->
<strong>Syntax:</strong> ServerName <em>fully-qualified domain name</em><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The ServerName directive sets the hostname of the server; this is only
used when creating redirection URLs. If it is not specified, then the
server attempts to deduce it from its own IP address; however this may
not work reliably, or may not return the preferred hostname. For example:
<blockquote><code>ServerName www.wibble.com</code></blockquote>
would be used if the canonical (main) name of the actual machine
were <code>monster.wibble.com</code>.<p>
<p><strong>See Also</strong>:
<a href="../dns-caveats.html">DNS Issues</a></p>
<hr>
<A name="serverpath"><h2>ServerPath directive</h2></A>
<strong>Syntax:</strong> ServerPath <em>pathname</em><br>
<strong>Context:</strong> virtual host<br>
<strong>Status:</strong> core<br>
<strong>Compatibility:</strong> ServerPath is only available in Apache
1.1 and later.<p>
The ServerPath directive sets the legacy URL pathname for a host, for
use with <a href="../host.html">Host-header based virtual hosts</a>.
<p><strong>See Also</strong>:
<a href="../vhosts-in-depth.html">In-depth description of Virtual Host matching</a></p>
<hr>
<A name="serverroot"><h2>ServerRoot directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ServerRoot} directive&gt; -->
<strong>Syntax:</strong> ServerRoot <em>directory-filename</em><br>
<strong>Default:</strong> <code>ServerRoot /usr/local/etc/httpd</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The ServerRoot directive sets the directory in which the server lives.
Typically it will contain the subdirectories <code>conf/</code> and
<code>logs/</code>. Relative paths for other configuration files are taken
as relative to this directory.<br>
See also <a href="../invoking.html">the <code>-d</code> option to httpd</a>.<p><hr>
<A name="servertype"><h2>ServerType directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt ServerType} directive&gt; -->
<strong>Syntax:</strong> ServerType <em>type</em><br>
<strong>Default:</strong> <code>ServerType standalone</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The ServerType directive sets how the server is executed by the system.
<em>Type</em> is one of
<dl>
<dt>inetd
<dd>The server will be run from the system process inetd; the command to start
the server is added to <code>/etc/inetd.conf</code>
<dt>standalone
<dd>The server will run as a daemon process; the command to start the server
is added to the system startup scripts. (<code>/etc/rc.local</code> or
<code>/etc/rc3.d/...</code>.)
</dl>
Inetd is the lesser used of the two options. For each http
connection received, a new copy of the server is started from scratch;
after the connection is complete, this program exits. There is a high price to
pay per connection, but for security reasons, some admins prefer this option.
<p>
Standalone is the most common setting for ServerType since
it is far more efficient. The server is started once, and services all
subsequent connections. If you intend running Apache to serve a busy site,
standalone will probably be your only option.<p>
SECURITY: if you are paranoid about security, run in inetd mode. Security
cannot be guaranteed in either, but whilst most people are happy to use
standalone, inetd is probably least prone to attack.<p><hr>
<A name="startservers"><h2>StartServers directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt StartServers} directive&gt; -->
<strong>Syntax:</strong> StartServers <em>number</em><br>
<strong>Default:</strong> <code>StartServers 5</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The StartServers directive sets the number of child server processes created
on startup. As the number of processes is dynamically controlled depending
on the load, there is usually little reason to adjust this parameter.<p>
See also <A HREF="#minspareservers">MinSpareServers</A> and
<A HREF="#maxspareservers">MaxSpareServers</A>.<p><hr>
<A name="timeout"><h2>TimeOut directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt TimeOut} directive&gt; -->
<strong>Syntax:</strong> TimeOut <em>number</em><br>
<strong>Default:</strong> <code>TimeOut 300</code><br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> core<p>
The TimeOut directive currently defines the amount of time Apache will
wait for three things:
<OL>
<LI>The total amount of time it takes to receive a GET request.
<LI>The amount of time between receipt of TCP packets on a POST or
PUT request.
<LI>The amount of time between ACKs on transmissions of TCP packets
in responses.
</OL>
We plan on making these separately configurable at some point down the
road. The timer used to default to 1200 before 1.2, but has been
lowered to 300 which is still far more than necessary in most
situations. It is not set any lower by default because there may
still be odd places in the code where the timer is not reset when
a packet is sent.
<p><hr>
<A name="user"><h2>User directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt User} directive&gt; -->
<strong>Syntax:</strong> User <em>unix-userid</em><br>
<strong>Default:</strong> <code>User #-1</code><br>
<strong>Context:</strong> server config, virtual host<br>
<strong>Status:</strong> core<p>
The User directive sets the userid as which the server will answer requests.
In order to use this directive, the standalone server must be run initially
as root. <em>Unix-userid</em> is one of:
<dl>
<dt>A username
<dd>Refers to the given user by name.
<dt># followed by a user number.
<dd>Refers to a user by their number.
</dl>
The user should have no privileges which result in it being able to access
files which are not intended to be visible to the outside world, and
similarly, the user should not be able to execute code which is not
meant for httpd requests. It is recommended that you set up a new user and
group specifically for running the server. Some admins use user
<code>nobody</code>, but this is not always possible or desirable.<p>
Notes: If you start the server as a non-root user, it will fail to change
to the lesser privileged user, and will instead continue to run as
that original user. If you do start the server as root, then it is normal
for the parent process to remain running as root.<p>
Special note: Use of this directive in &lt;VirtualHost&gt; requires a
properly configured <A HREF="../suexec.html">suEXEC wrapper</A>.
When used inside a &lt;VirtualHost&gt; in this manner, only the user
that CGIs are run as is affected. Non-CGI requests are still processed
with the user specified in the main User directive.<p>
SECURITY: Don't set User (or <A HREF="#group">Group</A>) to
<code>root</code> unless you know exactly what you are doing, and what the
dangers are.<p><hr>
<A name="virtualhost"><h2>&lt;VirtualHost&gt; directive</h2></A>
<!--%plaintext &lt;?INDEX {\tt VirtualHost} section directive&gt; -->
<strong>Syntax:</strong> &lt;VirtualHost <em>addr</em>[:<em>port</em>] ...&gt; ...
&lt;/VirtualHost&gt; <br>
<strong>Context:</strong> server config<br>
<strong>Status:</strong> Core.<br>
<strong>Compatibility:</strong> Non-IP address-based Virtual Hosting only
available in Apache 1.1 and later.<br>
<strong>Compatibility:</strong> Multiple address support only available in
Apache 1.2 and later.<p>
&lt;VirtualHost&gt; and &lt;/VirtualHost&gt; are used to enclose a group of
directives which will apply only to a particular virtual host.
Any directive which is allowed in a virtual host context may be used.
When the server receives a request for a document on a particular virtual
host, it uses the configuration directives enclosed in the &lt;VirtualHost&gt;
section. <em>Addr</em> can be
<menu>
<li>The IP address of the virtual host
<li>A fully qualified domain name for the IP address of the virtual host.
</menu> Example:
<blockquote>
<code>
&lt;VirtualHost 10.1.2.3&gt; <br>
ServerAdmin webmaster@host.foo.com <br>
DocumentRoot /www/docs/host.foo.com <br>
ServerName host.foo.com <br>
ErrorLog logs/host.foo.com-error_log <br>
TransferLog logs/host.foo.com-access_log <br>
&lt;/VirtualHost&gt;
</code></blockquote>
Each VirtualHost must correspond to a different IP address or a
different host name for the server, in the latter case the server
machine must be configured to accept IP packets for multiple
addresses. (If the machine does not have multiple network interfaces,
then this can be accomplished with the <code>ifconfig alias</code>
command (if your OS supports it), or with kernel patches like <A
HREF="../misc/vif-info.html">VIF</A> (for SunOS(TM) 4.1.x)).<p>
The special name <code>_default_</code> can be specified in which case
this virtual host will match any IP address that is not explicitly listed
in another virtual host. In the absence of any _default_ virtual host
the "main" server config, consisting of all those definitions outside
any VirtualHost section, is used when no match occurs.<p>
You can specify a <code>:port</code> to change the port that is matched.
If unspecified then it defaults to the same port as the most recent
<code><a href="#port">Port</a></code> statement of the main server. You
may also specify <code>:*</code> to match all ports on that address.
(This is recommended when used with <code>_default_</code>.)<p>
<strong>SECURITY</strong>: See the
<A HREF="../misc/security_tips.html">security tips</A>
document for details on why your security could be compromised if
the directory where logfiles are stored is writable by anyone other
than the user that starts the server.
<p><strong>See also:</strong>
<A HREF="../dns-caveats.html">Warnings about DNS and Apache</a><br>
<strong>See also:</strong>
<A HREF="../virtual-host.html">Information on Virtual Hosts.
(multihome)</A><br>
<strong>See also:</strong>
<a href="../host.html">Non-IP address-based Virtual Hosts</a><br>
<strong>See also:</strong>
<a href="../vhosts-in-depth.html">In-depth description of Virtual Host matching</a>
</p>
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