<?xml version="1.0"?>
<!DOCTYPE document [
  <!ENTITY project SYSTEM "project.xml">
]>
<document url="ajp.html">

  &project;

  <properties>
    <author email="remm@apache.org">Remy Maucherat</author>
    <author email="yoavs@apache.org">Yoav Shapira</author>
    <author email="arjaquith@mindspring.com">Andrew R. Jaquith</author>
    <title>The AJP Connector</title>
  </properties>

<body>


<section name="Introduction">

  <p>The <strong>AJP Connector</strong> element represents a
  <strong>Connector</strong> component that communicates with a web
  connector via the <code>AJP</code> protocol.  This is used for cases
  where you wish to invisibly integrate Tomcat 6 into an existing (or new)
  Apache installation, and you want Apache to handle the static content
  contained in the web application, and/or utilize Apache's SSL
  processing.</p>

  <p>This connector supports load balancing when used in conjunction with
  the <code>jvmRoute</code> attribute of the 
  <a href="engine.html">Engine</a>.</p>

<p>The native connectors supported with this Tomcat release are:
<ul>
<li>JK 1.2.x with any of the supported servers</li>
<li>mod_proxy on Apache httpd 2.x (included by default in Apache HTTP Server 2.2), 
with AJP enabled</li>
</ul>
</p>

<p><b>Other native connectors supporting AJP may work, but are no longer supported.</b></p>

</section>


<section name="Attributes">

  <subsection name="Common Attributes">

  <p>All implementations of <strong>Connector</strong>
  support the following attributes:</p>

  <attributes>

    <attribute name="allowTrace" required="false">
      <p>A boolean value which can be used to enable or disable the TRACE
      HTTP method. If not specified, this attribute is set to false.</p>
    </attribute>

    <attribute name="emptySessionPath" required="false">
      <p>If set to <code>true</code>, all paths for session cookies will be set
      to <code>/</code>. This can be useful for portlet specification implementations,
      but will greatly affect performance if many applications are accessed on a given
      server by the client.
      If not specified, this attribute is set to <code>false</code>.</p>
    </attribute>

    <attribute name="enableLookups" required="false">
      <p>Set to <code>true</code> if you want calls to
      <code>request.getRemoteHost()</code> to perform DNS lookups in
      order to return the actual host name of the remote client.  Set
      to <code>false</code> to skip the DNS lookup and return the IP
      address in String form instead (thereby improving performance).
      By default, DNS lookups are enabled.</p>
    </attribute>

    <attribute name="maxPostSize" required="false">
      <p>The maximum size in bytes of the POST which will be handled by
      the container FORM URL parameter parsing. The feature can be disabled by
      setting this attribute to a value less than or equal to 0.
      If not specified, this attribute is set to 2097152 (2 megabytes).</p>
    </attribute>

    <attribute name="maxSavePostSize" required="false">
      <p>The maximum size in bytes of the POST which will be saved/buffered by
      the container during FORM or CLIENT-CERT authentication. For both types
      of authentication, the POST will be saved/buffered before the user is
      authenticated. For CLIENT-CERT authentication, the POST is buffered for
      the duration of the SSL handshake and the buffer emptied when the request
      is processed. For FORM authentication the POST is saved whilst the user
      is re-directed to the login form and is retained until the user
      successfully authenticates or the session associated with the
      authentication request expires. The limit can be disabled by setting this
      attribute to -1. Setting the attribute to zero will disable the saving of
      POST data during authentication. If not specified, this attribute is set
      to 4096 (4 kilobytes).</p>
    </attribute>

    <attribute name="protocol" required="false">
      <p>This attribute value must be <code>AJP/1.3</code> to use the AJP
      handler.</p>
    </attribute>

    <attribute name="proxyName" required="false">
      <p>If this <strong>Connector</strong> is being used in a proxy
      configuration, configure this attribute to specify the server name
      to be returned for calls to <code>request.getServerName()</code>.
      See <a href="#Proxy Support">Proxy Support</a> for more
      information.</p>
    </attribute>

    <attribute name="proxyPort" required="false">
      <p>If this <strong>Connector</strong> is being used in a proxy
      configuration, configure this attribute to specify the server port
      to be returned for calls to <code>request.getServerPort()</code>.
      See <a href="#Proxy Support">Proxy Support</a> for more
      information.</p>
    </attribute>

    <attribute name="redirectPort" required="false">
      <p>If this <strong>Connector</strong> is supporting non-SSL
      requests, and a request is received for which a matching
      <code>&lt;security-constraint&gt;</code> requires SSL transport,
      Catalina will automatically redirect the request to the port
      number specified here.</p>
    </attribute>

    <attribute name="request.registerRequests" required="false">
      <p>This attribute controls request registration for JMX monitoring
      of the Connector.  It is enabled by default, but may be turned
      it off to save a bit of memory.</p>
    </attribute>

    <attribute name="scheme" required="false">
      <p>Set this attribute to the name of the protocol you wish to have
      returned by calls to <code>request.getScheme()</code>.  For
      example, you would set this attribute to "<code>https</code>"
      for an SSL Connector.  The default value is "<code>http</code>".
      See <a href="#SSL Support">SSL Support</a> for more information.</p>
    </attribute>

    <attribute name="secure" required="false">
      <p>Set this attribute to <code>true</code> if you wish to have
      calls to <code>request.isSecure()</code> to return <code>true</code>
      for requests received by this Connector (you would want this on an
      SSL Connector).  The default value is <code>false</code>.</p>
    </attribute>

    <attribute name="URIEncoding" required="false">
      <p>This specifies the character encoding used to decode the URI bytes,
      after %xx decoding the URL. If not specified, ISO-8859-1 will be used.
      </p>
    </attribute>

    <attribute name="useBodyEncodingForURI" required="false">
      <p>This specifies if the encoding specified in contentType should be used
      for URI query parameters, instead of using the URIEncoding. This
      setting is present for compatibility with Tomcat 4.1.x, where the
      encoding specified in the contentType, or explicitely set using
      Request.setCharacterEncoding method was also used for the parameters from
      the URL. The default value is <code>false</code>.
      </p>
    </attribute>

    <attribute name="useIPVHosts" required="false">
      <p>Set this attribute to <code>true</code> to cause Tomcat to use
      the ServerName passed by the native web server to determine the Host
      to send the request to.  The default value is <code>false</code>.</p>
    </attribute>

    <attribute name="xpoweredBy" required="false">
      <p>Set this attribute to <code>true</code> to cause Tomcat to advertise
      support for the Srevlet specification using the header recommended in the
      specification.  The default value is <code>false</code>.</p>
    </attribute>

  </attributes>

  </subsection>

  <subsection name="Standard Implementation">

  <p>To use AJP, you
  must specify the protocol attribute (see above).</p>

  <p><strong>This implementation supports the AJP 1.3 protocol.</strong></p>

  <p>It supports the following additional attributes (in addition to the
  common attributes listed above):</p>

  <attributes>

    <attribute name="address" required="false">
      <p>For servers with more than one IP address, this attribute
      specifies which address will be used for listening on the specified
      port.  By default, this port will be used on all IP addresses
      associated with the server. A value of <code>127.0.0.1</code>
      indicates that the Connector will only listen on the loopback
      interface.</p>
    </attribute>

    <attribute name="backlog" required="false">
      <p>The maximum queue length for incoming connection requests when
      all possible request processing threads are in use.  Any requests
      received when the queue is full will be refused.  The default
      value is 10.</p>
    </attribute>

    <attribute name="bufferSize" required="false">
      <p>The size of the output buffer to use.  If less than or equal to zero,
         then output buffering is disabled.  The default value is -1
         (i.e. buffering disabled)</p>
    </attribute>

    <attribute name="connectionTimeout" required="false">
      <p>The number of milliseconds this <strong>Connector</strong> will wait,
      after accepting a connection, for the request URI line to be
      presented.  The default value is infinite (i.e. no timeout).</p>
    </attribute>

    <attribute name="minProcessors" required="false">
      <strong>deprecated</strong>
      <p>The minimum number of processors to start at initialization time.
      If not specified, this atttribute is set to 5.</p>
    </attribute>

    <attribute name="maxProcessors" required="false">
      <strong>deprecated</strong>
      <p>The maximum number of processors allowed. This should be
      set to a value that is greater than or equal to the maximum number
      of concurrent connections the remote web server can open to Tomcat 
      simultaneously. For example, if the web server is Apache 1.x or 2.x
      Tomcat's <code>maxProcessors</code> should be set to the 
      value of Apache's <code>maxClients</code> directive.</p>
      <p>A <code>maxProcessors</code> value of zero (0) signifies that 
      the number of processors is unlimited. If not specified, this
      atttribute defaults to 20.</p>
     </attribute>

    <attribute name="maxSpareThreads" required="false">
      <p>The maximum number of unused request processing threads that
      will be allowed to exist until the thread pool starts stopping the
      unnecessary threads.  The default value is 50.</p>
    </attribute>

    <attribute name="maxThreads" required="false">
      <p>The maximum number of request processing threads to be created
      by this <strong>Connector</strong>, which therefore determines the
      maximum number of simultaneous requests that can be handled.  If
      not specified, this attribute is set to 200.</p>
    </attribute>

    <attribute name="minSpareThreads" required="false">
      <p>The number of request processing threads that will be created
      when this <strong>Connector</strong> is first started.  The connector
      will also make sure it has the specified number of idle processing
      threads available. This attribute should be set to a value smaller
      than that set for <code>maxThreads</code>.  The default value is 4.</p>
    </attribute>

    <attribute name="port" required="true">
      <p>The TCP port number on which this <strong>Connector</strong>
      will create a server socket and await incoming connections.  Your
      operating system will allow only one server application to listen
      to a particular port number on a particular IP address.</p>
    </attribute>

    <attribute name="tcpNoDelay" required="false">
      <p>If set to <code>true</code>, the TCP_NO_DELAY option will be
      set on the server socket, which improves performance under most
      circumstances.  This is set to <code>true</code> by default.</p>
    </attribute>

    <attribute name="tomcatAuthentication" required="false">
      <p>If set to <code>true</code>, the authetication will be done in Tomcat. 
      Otherwise, the authenticated principal will be propagated from the native
      webaserver and used for authorization in Tomcat.  
      The default value is <code>true</code>.</p>
    </attribute>

  </attributes>

  </subsection>

</section>


<section name="Nested Components">

  <p>None at this time.</p>

</section>


</body>

</document>
