Simple HTTP clustering without WAS Network Deployment
JonMarshall 1000009QM4 Visits (1856)
"I need to do clustering with WebSphere Application Server, therefore I need WebSphere Application Server Network Deployment. Right?"
Well, not quite.
There was a little change to the licensing terms and conditions that was sneaked in with the release of WAS v18.104.22.168 fixpak.
This allows the WAS (base) and WAS Express products to use what we've come to call "Simple HTTP Load balancing and failover". It is more manual work than with WAS ND, but can provide a more cost effective solution if not using all of the WAS ND high end function.
We're used clustering being available in WAS Network Deployment. This provides the Deployment Manager, which provides a central point of administration to manage a distributed environment and clustered application servers. The clustering of application servers allows for the load balancing and failover of HTTP, EJB, Transactional and Messaging workloads.
By comparison, the Simple HTTP load balancing and failover is just manually configuring the web server plugin to provide HTTP routing to 2 or more standalone WebSphere Application Servers.
There is no centralised administration (although the v7 features admin agent and job manager provide a neat option here), there is no centralised deployment of applications, and so on.
To do this, we need to consider some licensing terms (groan!) and then the mechanics of manually configuring it.
<EDIT Oct 14th 2013>The following licensing restrictions are removed as of WAS v8.5.5. It is now permitted for an unlimited number of profiles to be load balanced across WAS base, Express and Liberty core as stated in the anno
How to configure it
That's enough licensing. It is dead easy to configure and you can find that well described in the InfoCenter
The key steps are to configure session affinity and then to merge the plugin configuration files from the various application server profiles. WebSphere provides the pluginMerge tool to do that for you