The communication between the HTTP server and Geronimo can also be done via AJP connectors. By default, both Apache Geronimo distributions (Jetty and Tomcat) have already predefined one AJP13 connector listening on port 8009.

The Jakarta Tomcat Connector mod_jk module is provided as a connector from Apache Tomcat source. Both Jetty and Tomcat are fully compatible with this connector. This module is available when you download the Tomcat source, but you can also download it separately. See http://tomcat.apache.org/download-connectors.cgi for the proper version for your system.

In addition to mod_jk, you will require a workers.properties file, also available with the Apache Tomcat source distribution. This properties file tells the mod_jk plugin how to connect to the Geronimo server. For a detailed explanation on all the available options for configuring the Jakarta Tomcat Connector, visit http://tomcat.apache.org/connectors-doc/config/workers.html.

For practical purposes, the module mod_jk-apache-2.2.3.so for Windows and the workers.properties are included in the Attachments section in this article.

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Configure Apache HTTPd

Download the appropriate mod_jk for your platform from the Tomcat web site. For this particular example, rename it to mod_jk.so and copy it into the <httpd_home>\modules directory. Download and extract the workers.properties file from the Apache Tomcat source (alternatively, download it from the Attachments section) to the <httpd_home>\conf directory.

Edit the httpd.conf file located in the <httpd_home>\conf directory to load the Jakarta Tomcat Connector mod_jk module. Add the following lines at the end of the httpd.conf file.

Excerpt from httpd.conf

LoadModule jk_module modules/mod_jk.so			
# Loads the Jakarta Tomcat Connector module

JkWorkersFile <httpd_home>\conf\workers.properties
# Tells the module the location of the workers.properties file

JkLogFile     <httpd_home>\logs\mod_jk.log
# Specifies the location for this module's specific log file

JkLogLevel    info
# Sets the module's log level to info

JkMount /console/* ajp13
# Sets a mount point from a context to a Tomcat worker. In this case will allow access (forward the request) to the console.

JkMount will map anything behind /console/ to the worker ajp13. The name ajp13 is defined in the workers.properties file, which is described in the following section. You might need to add more JkMount directives depending on the applications you want to be accessed via the remote HTTPd.

In this example, the console has been enabled just for demonstration purposes. In a production environment, you do not want to have the console accessible from the other network (normally the Internet). Having the console accessible represents a big security exposure.

The rule is that everything should have restricted access. Normally, a firewall would be placed in between the HTTP and the application server (depending on the topology) and you should map just the minimum resources necessary to have your application working from the other side.

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Configure workers.properties

The workers.properties file, among other things, tells the HTTPd where the Geronimo server is, what version of AJP to use and the port where Geronimo is listening.

Edit the workers.properties file located in the <httpd_home>\conf directory to match your environment. The following example is an excerpt from the workers.properties file with just the variables you should focus on.

Minimum requirements for the workers.properties

worker.ajp13.type=ajp13
# Sets the version of AJP used. The AJP listeners defined in Geronimo are AJP v13.

worker.ajp13.host=localhost
# Specifies the location of the Geronimo server. Use default localhost for single-tier scenarios. Specify the
# hostname of the Geronimo server for multi-tier environments.

worker.ajp13.port=8009
# Both Tomcat and Jetty come with a predefined AJP13 listener on port 8009

From this example, note how the name of the worker is defined. Look at the variables definition worker.ajp13 , where ajp13 is the worker name you specified earlier in the httpd.conf file.

As the last step, stop and restart the Apache HTTPd to ensure these changes are loaded.

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Testing

For testing this configuration, make sure both Geronimo and HTTPd are up and running.

Check Geronimo connectivity by accessing http://localhost:8080/console , you should see the Geronimo Administration Console.
Check HTTPd connectivity by accessing http://localhost , you should see the Apache HTTPd welcome page.
Check the HTTPd - Geronimo request forwarding by accessing http://localhost/console/ , you shoud be redirected to the Geronimo Administration Console. Note that at the end of the URL, there is a "/", failing to include this / will result in a Not Found error triggered by the Jakarta Tomcat Connector module.

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