19.5.3. Install the mod_cluster Module Into Apache HTTP Server or JBoss Enterprise Web Server (Zip)


  • To perform this task, you must be using Apache HTTP Server installed in Red Hat Enterprise Linux 6, or JBoss Enterprise Web Server, or the standalone Apache HTTP Server included as a separate downloadable component of JBoss EAP 6.
  • If you need to install Apache HTTP Server in Red Hat Enterprise Linux 6, use the instructions from the Red Hat Enterprise Linux 6 Deployment Guide.
  • If you need to install the standalone Apache HTTP Server included as a separate downloadable component of JBoss EAP 6, refer to Section 19.3.2, “Install the Apache HTTP Server included with JBoss EAP 6 (Zip)”.
  • If you need to install JBoss Enterprise Web Server, use the instructions from the JBoss Enterprise Web Server Installation Guide.
  • Download the Webserver Connecter Natives package for your operating system and architecture from the Red Hat Customer Portal at https://access.redhat.com. This package contains the mod_cluster binary web server modules precompiled for your operating system. After you extract the archive, the modules are located in the EAP_HOME/modules/system/layers/base/native/lib/httpd/modules directory.
    The etc/ directory contains some example configuration files, and the share/ directory contains some supplemental documentation.
  • You must be logged in with administrative (root) privileges.


If you use a 64 bit system the mod_cluster binary web server modules will be located here: EAP_HOME/modules/system/layers/base/native/lib64/httpd/modules. You must use this path whenever you need access to the modules.

Procedure 19.7. Install the mod_cluster Module

  1. Determine your Apache HTTP Server configuration location.

    Your Apache HTTP Server configuration location will be different depending on whether you are using Red Hat Enterprise Linux's Apache HTTP Server, the standalone Apache HTTP Server included as a separate downloadable component with JBoss EAP 6, or the Apache HTTP Server available in JBoss Enterprise Web Server. It is one of the following three options, and is referred to in the rest of this task as HTTPD_HOME.
    • Apache HTTP Server - /etc/httpd/
    • JBoss EAP 6 Apache HTTP Server - This location is chosen by you, based on the requirements of your infrastructure.
    • JBoss Enterprise Web Server Apache HTTP Server - EWS_HOME/httpd/
  2. Copy the modules to the Apache HTTP Server modules directory.

    Copy the four modules (the files ending in .so) from the EAP_HOME/modules/system/layers/base/native/lib/httpd/modules directory of the extracted Webserver Natives archive to the HTTPD_HOME/modules/ directory.
  3. For JBoss Enterprise Web Server, disable the mod_proxy_balancer module.

    If you use JBoss Enterprise Web Server, the mod_proxy_balancer module is enabled by default. It is incompatible with mod_cluster. To disable it, edit the HTTPD_HOME/conf/httpd.conf and comment out the following line by placing a # (hash) symbol before the line which loads the module. The line is shown without the comment and then with it, below.
    LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
    # LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
    Save and close the file.
  4. Configure the mod_cluster module.

    The Webserver Natives archive contains a sample mod_cluster.conf file (EAP_HOME/modules/system/layers/base/native/etc/httpd/conf). This file can be used as a guide or copied and edited to create a HTTPD_HOME/httpd/conf.d/JBoss_HTTP.conf file.


    Using the name JBoss_HTTP.conf is an arbitrary convention in this document. The configuration file will be loaded, regardless of its name, if it is saved in the conf.d/ directory with the .conf extension.
    Add the following to your configuration file:
    LoadModule slotmem_module modules/mod_slotmem.so
    LoadModule manager_module modules/mod_manager.so
    LoadModule proxy_cluster_module modules/mod_proxy_cluster.so
    LoadModule advertise_module modules/mod_advertise.so
    This causes Apache HTTP Server to automatically load the modules that mod_cluster needs in order to function.
  5. Create a proxy server listener.

    Continue editing HTTPD_HOME/httpd/conf.d/JBoss_HTTP.conf and add the following minimal configuration, replacing the values in capital letters with suitable values for your environment.
    <VirtualHost IP_ADDRESS:PORT>  
    	  <Location />
              Order deny,allow
              Deny from all
              Allow from *.MYDOMAIN.COM
    	  KeepAliveTimeout 60
    	  MaxKeepAliveRequests 0
    	  EnableMCPMReceive On
    	  ManagerBalancerName mycluster
    	  ServerAdvertise On
    These directives create a new virtual server which listens on IP_ADDRESS:PORT, allows connections from MYDOMAIN.COM, and advertises itself as a balancer called mycluster. These directives are covered in detail in the documentation for Apache Web Server. To learn more about the ServerAdvertise and EnableMCPMReceive directives, and the implications of server advertisement, see Section 19.5.5, “Configure Server Advertisement Properties for Your mod_cluster-enabled Web Server”.
    Save the file and exit.
  6. Restart the Apache HTTP Server.

    The way to restart the Apache HTTP Server depends on whether you are using Red Hat Enterprise Linux's Apache HTTP Server or the Apache HTTP Server included in JBoss Enterprise Web Server. Choose one of the two methods below.
    • Red Hat Enterprise Linux 6 Apache HTTP Server

      Issue the following command:
      [root@host]# service httpd restart
    • JBoss Enterprise Web Server HTTP Server

      JBoss Enterprise Web Server runs on both Red Hat Enterprise Linux and Microsoft Windows Server. The method for restarting the Apache HTTP Server is different for each.
      • Red Hat Enterprise Linux

        In Red Hat Enterprise Linux, JBoss Enterprise Web Server installs its Apache HTTP Server as a service. To restart the Apache HTTP Server, issue the following two commands:
        [root@host ~]# service httpd stop
        [root@host ~]# service httpd start
      • Microsoft Windows Server

        Issue the following commands in a command prompt with administrative privileges:
        C:\> net stop httpd
        C:\> net start httpd

The Apache HTTP Server is now configured as a load balancer, and can work with the mod_cluster subsystem running JBoss EAP 6. To configure JBoss EAP 6 to be aware of mod_cluster, see Section 19.5.6, “Configure a mod_cluster Worker Node”.