The AJP Connector element represents a
Connector component that communicates with a web
connector via the AJP protocol. This is used for cases
where you wish to invisibly integrate Tomcat 5 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
This connector supports load balancing when used in conjunction with
the jvmRoute attribute of the
The native connectors supported with this Tomcat release are:
JK 1.2.x with any of the supported servers
mod_proxy on Apache httpd 2.x (included by default in Apache HTTP Server 2.2),
with AJP enabled
Other native connectors supporting AJP may work, but are no longer supported.
All implementations of Connector
support the following attributes:
A boolean value which can be used to enable or disable the TRACE
HTTP method. If not specified, this attribute is set to false.
If set to true, all paths for session cookies will be set
to /. 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 false.
Set to true if you want calls to
request.getRemoteHost() to perform DNS lookups in
order to return the actual host name of the remote client. Set
to false to skip the DNS lookup and return the IP
address in String form instead (thereby improving performance).
By default, DNS lookups are enabled.
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).
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).
This attribute value must be AJP/1.3 to use the AJP
If this Connector is being used in a proxy
configuration, configure this attribute to specify the server name
to be returned for calls to request.getServerName().
See Proxy Support for more
If this Connector is being used in a proxy
configuration, configure this attribute to specify the server port
to be returned for calls to request.getServerPort().
See Proxy Support for more
If this Connector is supporting non-SSL
requests, and a request is received for which a matching
<security-constraint> requires SSL transport,
Catalina will automatically redirect the request to the port
number specified here.
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.
Set this attribute to the name of the protocol you wish to have
returned by calls to request.getScheme(). For
example, you would set this attribute to "https"
for an SSL Connector. The default value is "http".
See SSL Support for more information.
Set this attribute to true if you wish to have
calls to request.isSecure() to return true
for requests received by this Connector (you would want this on an
SSL Connector). The default value is false.
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.
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 false.
Set this attribute to true 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 false.
Set this attribute to true to cause Tomcat to advertise
support for the Srevlet specification using the header recommended in the
specification. The default value is false.
To use AJP, you
must specify the protocol attribute (see above).
This implementation supports the AJP 1.3 protocol.
It supports the following additional attributes (in addition to the
common attributes listed above):
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 127.0.0.1
indicates that the Connector will only listen on the loopback
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 100.
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)
The number of milliseconds this Connector will wait,
after accepting a connection, for the request URI line to be
presented. The default value is infinite (i.e. no timeout).
The minimum number of processors to start at initialization time.
If not specified, this atttribute is set to 5.
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 maxProcessors should be set to the
value of Apache's maxClients directive.
A maxProcessors value of zero (0) signifies that
the number of processors is unlimited. If not specified, this
atttribute defaults to 20.
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.
The maximum number of request processing threads to be created
by this Connector, which therefore determines the
maximum number of simultaneous requests that can be handled. If
not specified, this attribute is set to 200.
The number of request processing threads that will be created
when this Connector 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 maxThreads. The default value is 4.
The TCP port number on which this Connector
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.
If set to true, the TCP_NO_DELAY option will be
set on the server socket, which improves performance under most
circumstances. This is set to true by default.
If set to true, 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 true.