7.6.1.1. Installing and Setting up a Load Balancer

Let us consider the installation of a load balancer based on Apache HTTP Server for Ubuntu 14.04.

  1. Install Apache HTTP Server and its mod_jk module:

    $ sudo apt-get install apache2 libapache2-mod-jk

  2. Replace the contents of the /etc/libapache2-mod-jk/workers.properties file with the following:

    workers.tomcat_home=
    workers.java_home=
    ps=/
    
    worker.list=tomcat1,tomcat2,loadbalancer,jkstatus
    
    worker.tomcat1.port=8009
    worker.tomcat1.host=host1
    worker.tomcat1.type=ajp13
    worker.tomcat1.connection_pool_timeout=600
    worker.tomcat1.lbfactor=1
    
    worker.tomcat2.port=8009
    worker.tomcat2.host=host2
    worker.tomcat2.type=ajp13
    worker.tomcat2.connection_pool_timeout=600
    worker.tomcat2.lbfactor=1
    
    worker.loadbalancer.type=lb
    worker.loadbalancer.balance_workers=tomcat1,tomcat2
    
    worker.jkstatus.type=status
  3. Add the lines listed below to /etc/apache2/sites-available/000-default.conf:

    <VirtualHost *:80>
    ...
        <Location /jkmanager>
            JkMount jkstatus
            Order deny,allow
            Allow from all
        </Location>
    
        JkMount /jkmanager/* jkstatus
        JkMount /app loadbalancer
        JkMount /app/* loadbalancer
    
    </VirtualHost>
  4. Restart the Apache HTTP service:

    $ sudo service apache2 restart