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    <title>Server-Wide Configuration</title>
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      <h3>Apache HTTP Server</h3>
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    <h1 align="center">Server-Wide Configuration</h1>

    <p>This document explains some of the directives provided by
    the <a href="mod/core.html">core</a> server which are used to
    configure the basic operations of the server.</p>

    <ul>
      <li><a href="#identification">Server Identification</a></li>

      <li><a href="#locations">File Locations</a></li>

      <li><a href="#process">Process Creation</a></li>

      <li><a href="#network">Network Configuration</a></li>

      <li><a href="#resource">Limiting Resource Usage</a></li>
    </ul>
    <hr />

    <h2><a id="identification" name="identification">Server
    Identification</a></h2>

    <table border="1">
      <tr>
        <td valign="top"><strong>Related Directives</strong><br />
         <br />
         <a href="mod/core.html#servername">ServerName</a><br />
         <a href="mod/core.html#serveradmin">ServerAdmin</a><br />
         <a
        href="mod/core.html#serversignature">ServerSignature</a><br />
         <a
        href="mod/core.html#servertokens">ServerTokens</a><br />
         <a
        href="mod/core.html#usecanonicalname">UseCanonicalName</a><br />
         </td>
      </tr>
    </table>

    <p>The <code>ServerAdmin</code> and <code>ServerTokens</code>
    directives control what information about the server will be
    presented in server-generated documents such as error messages.
    The <code>ServerTokens</code> directive sets the value of the
    Server HTTP response header field.</p>

    <p>The <code>ServerName</code> and
    <code>UseCanonicalName</code> directives are used by the server
    to determine how to construct self-referential URLs. For
    example, when a client requests a directory, but does not
    include the trailing slash in the directory name, Apache must
    redirect the client to the full name including the trailing
    slash so that the client will correctly resolve relative
    references in the document.</p>
    <hr />

    <h2><a id="locations" name="locations">File Locations</a></h2>

    <table border="1">
      <tr>
        <td valign="top"><strong>Related Directives</strong><br />
         <br />
         <a
        href="mod/core.html#coredumpdirectory">CoreDumpDirectory</a><br />
         <a
        href="mod/core.html#documentroot">DocumentRoot</a><br />
         <a href="mod/core.html#errorlog">ErrorLog</a><br />
         <a href="mod/core.html#lockfile">Lockfile</a><br />
         <a href="mod/core.html#pidfile">PidFile</a><br />
         <a
        href="mod/core.html#scoreboardfile">ScoreBoardFile</a><br />
         <a href="mod/core.html#serverroot">ServerRoot</a><br />
         </td>
      </tr>
    </table>

    <p>These directives control the locations of the various files
    that Apache needs for proper operation. When the pathname used
    does not begin with a slash "/", the files are located relative
    to the <code>ServerRoot</code>. Be careful about locating files
    in paths which are writable by non-root users. See the <a
    href="misc/security_tips.html">security tips</a> documentation
    for more details.</p>
    <hr />

    <h2><a id="process" name="process">Process Creation</a></h2>

    <table border="1">
      <tr>
        <td valign="top"><strong>Related Directives</strong><br />
         <br />
         <a
        href="mod/core.html#bs2000account">BS2000Account</a><br />
         <a href="mod/core.html#group">Group</a><br />
         <a href="mod/core.html#maxclients">MaxClients</a><br />
         <a
        href="mod/core.html#maxrequestsperchild">MaxRequestsPerChild</a><br />
         <a
        href="mod/core.html#maxspareservers">MaxSpareServers</a><br />
         <a
        href="mod/core.html#minspareservers">MinSpareServers</a><br />
         <a href="mod/core.html#servertype">ServerType</a><br />
         <a
        href="mod/core.html#startservers">StartServers</a><br />
         <a
        href="mod/core.html#threadsperchild">ThreadsPerChild</a><br />
         <a href="mod/core.html#user">User</a><br />
         </td>
      </tr>
    </table>

    <p>When <code>ServerType</code> is set to its recommended value
    of <code>Standalone</code>, Apache 1.3 for Unix is a
    pre-forking web server. A single control process is responsible
    for launching child processes which listen for connections and
    serve them when they arrive. Apache always tries to maintain
    several <em>spare</em> or idle server processes, which stand
    ready to serve incoming requests. In this way, clients do not
    need to wait for a new child processes to be forked before
    their requests can be served.</p>

    <p>The <code>StartServers</code>, <code>MinSpareServers</code>,
    <code>MaxSpareServers</code>, and <code>MaxServers</code>
    regulate how the parent process creates children to serve
    requests. In general, Apache is very self-regulating, so most
    sites do not need to adjust these directives from their default
    values. Sites which need to serve more than 256 simultaneous
    requests may need to increase <code>MaxClients</code>, while
    sites with limited memory may need to decrease
    <code>MaxClients</code> to keep the server from thrashing
    (swapping memory to disk and back). More information about
    tuning process creation is provided in the <a
    href="misc/perf-tuning.html">performance hints</a>
    documentation.</p>

    <p>While the parent process is usually started as root under
    Unix in order to bind to port 80, the child processes are
    launched by Apache as a less-privileged user. The
    <code>User</code> and <code>Group</code> directives are used to
    set the privileges of the Apache child processes. The child
    processes must be able to read all the content that will be
    served, but should have as few privileges beyond that as
    possible. In addition, unless <a href="suexec.html">suexec</a>
    is used, these directives also set the privileges which will be
    inherited by CGI scripts.</p>

    <p><code>MaxRequestsPerChild</code> controls how frequently the
    server recycles processes by killing old ones and launching new
    ones.</p>

    <p>Under Windows, Apache launches one control process and one
    child process. The child process creates multiple threads to
    serve requests. The number of threads is controlled by the
    <code>ThreadsPerChild</code> directive.</p>
    <hr />

    <h2><a id="network" name="network">Network
    Configuration</a></h2>

    <table border="1">
      <tr>
        <td valign="top"><strong>Related Directives</strong><br />
         <br />
         <a href="mod/core.html#bindaddress">BindAddress</a><br />
         <a href="mod/core.html#keepalive">KeepAlive</a><br />
         <a
        href="mod/core.html#keepalivetimeout">KeepAliveTimeout</a><br />
         <a href="mod/core.html#listen">Listen</a><br />
         <a
        href="mod/core.html#listenbacklog">ListenBackLog</a><br />
         <a
        href="mod/core.html#acceptfilter">AcceptFilter</a><br />
         <a href="mod/core.html#acceptmutex">AcceptMutex</a><br />
         <a
        href="mod/core.html#maxkeepaliverequests">MaxKeepAliveRequests</a><br />
         <a href="mod/core.html#port">Port</a><br />
         <a
        href="mod/core.html#sendbuffersize">SendBufferSize</a><br />
         <a href="mod/core.html#timeout">TimeOut</a><br />
         </td>
      </tr>
    </table>

    <p>When Apache starts, it connects to some port and address on
    the local machine and waits for incoming requests. By default,
    it listens to all addresses on the machine, and to the port as
    specified by the <code>Port</code> directive in the server
    configuration. However, it can be told to listen to more than
    one port, to listen to only selected addresses, or a
    combination. This is often combined with the <a
    href="vhosts/">Virtual Host</a> feature which determines how
    Apache responds to different IP addresses, hostnames and
    ports.</p>

    <p>There are two directives used to restrict or specify which
    addresses and ports Apache listens to. The
    <code>BindAddress</code> directive is used to restrict the
    server to listening to a single IP address. The
    <code>Listen</code> directive can be used to specify multiple
    IP addresses and/or Ports to which Apache will listen.</p>

    <p>The <code>ListenBackLog</code>, <code>SendBufferSize</code>,
    and <code>TimeOut</code> directives are used to adjust how
    Apache interacts with the network.<code>AcceptFilter</code>
    controls a BSD specific filter optimization. See the BSD
    section on <a href="misc/perf-bsd44.html">performance hints</a>
    documentation. <code>AcceptMutex</code> controls which accept
    mutex method will be used. For an explanation of what this is
    and why it's needed, see the <a
    href="misc/perf-tuning.html">performance tuning guide</a></p>

    <p>The <code>KeepAlive</code>, <code>KeepAliveTimeout</code>,
    and <code>MaxKeepAliveRequests</code> directives are used to
    configure how Apache handles persistent connections.</p>
    <hr />

    <h2><a id="resource" name="resource">Limiting Resource
    Usage</a></h2>

    <table border="1">
      <tr>
        <td valign="top"><strong>Related Directives</strong><br />
         <br />
         <a
        href="mod/core.html#limitrequestbody">LimitRequestBody</a><br />
         <a
        href="mod/core.html#limitrequestfields">LimitRequestFields</a><br />
         <a
        href="mod/core.html#limitrequestfieldsize">LimitRequestFieldsize</a><br />
         <a
        href="mod/core.html#limitrequestline">LimitRequestLine</a><br />
         <a href="mod/core.html#rlimitcpu">RLimitCPU</a><br />
         <a href="mod/core.html#rlimitmem">RLimitMEM</a><br />
         <a href="mod/core.html#rlimitnproc">RLimitNPROC</a><br />
         <a
        href="mod/core.html#threadstacksize">ThreadStackSize</a><br />
         </td>
      </tr>
    </table>

    <p>The <code>LimitRequest</code>* directives are used to place
    limits on the amount of resources Apache will use in reading
    requests from clients. By limiting these values, some kinds of
    denial of service attacks can be mitigated.</p>

    <p>The <code>RLimit</code>* directives are used to limit the
    amount of resources which can be used by processes forked off
    from the Apache children. In particular, this will control
    resources used by CGI scripts and SSI exec commands.</p>

    <p>The <code>ThreadStackSize</code> directive is used only on
    Netware to control the stack size.</p>
        <hr />

    <h3 align="CENTER">Apache HTTP Server</h3>
    <a href="./"><img src="images/index.gif" alt="Index" /></a>

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