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Free Sun webinar: Make Applications Highly Available: Load Balancing GlassFish Clusters

Hi guys,
today I attended at my first SUN webinar. Hopefully it won't be my last one with SUN, because I really liked it. It started very amusing with a hint regarding questions about Oracle. So, if you have questions regarding the Oracle Sun deal, please go to or website. We won't respond on questions about this.

John Clingan, the GlassFish Group Product Manager, started this webinar with a presentation of the benefits of open source and keywords like: productivity focus, community and transparency, annual subscriptions, performance tuned and pay at point of value. Then he introduced the Sun GlassFish portfolio at a high level. The Enterprise Server, the Web Space Server (portal for website development and collaborative workspaces), Web Stack (a complete LAMP stack) and Glassfish ESB.

The main focus of this 1-hour webinar was on High Availability and Load Balancing with GlassFish V2.1. He quickly explained the features of the High Availability Database (HADB) with its 5-9s and the in-memory replication. If you want to have more information, I recommend reading the administration guide or this slideshow. After John, Shreedhar Ganapathy continued with his part about Load Balancing. He answered the question why Load Balancing is so important. If you want to meet business SLA's you have to have scalability to address any growth requirement. Fault tolerance is also very important to prevent any service degradation. Later he explained the GlassFish Load Balancing Plugin, which works with SunWebServer, Apache WebServer and Microsoft IIS.

Then it was time for the first demo. John showed us how to install Sun GlassFish Enterprise Server v2.1 with HADB on a Solaris platform. Apparently, it didn't work because of some problems while providing the path of the installed webserver. Therefore, this step was skipped and instead replaced with a demo deployment of a HA JSP Sample Application. The application was deployed on a cluster consisting of 2 instances. It showed us how to keep values in a HTTP session if one instance fails (they stopped one instance manually).

The last 10 minutes of the webinar were dedicated to questions: Here are some examples: I asked what makes GlassFish clustering and Load Balancing better than what IBM Websphere offers? Answer: It is much easier to install and support and administer through a centralized UI. In addition, it is the only Open Source App Server that supports 5 9s availability. Another question was: What will healthchecking actually do? Check if there are any exceptions thrown? Healthchecking checks, whether instances in a cluster are alive, dead or slow. What is a node agent or what is IIOP or even what is EJB ;) ? There were many different questions. As John couldn't answer all of them, he got support from other experts.

As already mentioned, I really enjoyed this webinar. The skill of the speakers is amazing. You can ask questions to the real GlassFish experts. Of course you can't teach a topic like this in only one hour, but the speakers did a great job in giving an overview. I have to admit that I still have to learn a lot about High Availability and clustered environments. Until now, I didn't care much about this topic as it didn't affect my work as a developer that much. But there's lots of great documentation to read....which I will start with....tomorrow..


  1. On the subject of load balancing, why not get the highest availability while not getting caught in high prices? Kemp’s got some great load balancers that are low priced and high in quality:

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