7.4.1.1. 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