How does IHS load balancing work?
IHS or the IBM HTTP Server is an apache HTTP server implementation with a topping of IBM configuration. IHS is not a part of WebSphere but you can install it separately and add it to WebSphere, that way you can manage it using the WebSphere console.
In addition to all the function of a webserver, IHS can also be used to as a load balancer which means you can use IHS to spread the traffic evenly across all your JVMs and in case a JVM crashes or is otherwise down, traffic won’t be routed to that JVM.
For IHS to do the load balancing it should have the understanding of the clusters, JVMs that are there in those clusters, virtual hosts, context roots, etc. and since IHS is not a part of WebSphere there needs to be a way for it to do that, this is where the plugin comes in. The plugin is basically an xml file that has details of the clusters and it members, virtual hosts associated to the applications on the clusters and a lot of other details. By default this file is updated every minute to keep the latest configurations updated.
The plugin has to be installed separately and should be linked to the IHS. If you use the launch pad to install the plugin, it takes care of associating the plugin to the IHS, if you are installing it manually you need to make sure you link it to the IHS.
That’s it for today!
Until next time!