Kshitiz has a note on the new Java-based Converged Load Balancer that will be part of SailFin and GlassFish v2.1. The CLB handles both HTTP and SIP traffic and can be used with and without a hardware IP sprayer. Check Kshitiz's Detailed Writeup for details on load balancing algorithms and configuration options.

GlassFish doesn't trade enterprise features such as management and monitoring for Open Source. Masoud Kalali's recent article on java.net is a good illustration of this. It shows how the JMX-based administration infrastructure can be accessed to dynamically change the behavior of the HTTP load-balancer. The article first goes into what JMX and GlassFish AMX's are before introducing GlassFish v2's Management Rules mechanism. The rest is a detailed explanation of how to create and deploy the MBean to manage the weight of the load-balancer algorithm and the corresponding management rule.

Masoud had previously written detailed blog entries about:
- How to Secure GlassFish installation.
- GlassFish version 2 monitoring capabilities

GlassFish has had mod_jk support since GFv1; a common use case is where Apache httpd server is serving static pages and delegating to GlassFish for dynamic content.

The any-day-now GFv2 UR1 release also supports the case where httpd works as a load balancer to a cluster of GF instances, and Jan's latest note describes in detail how this works out.

Jan's entry not just describes how to configure httpd and GF but it also includes an architectural overview, explaining how jvmRoute works in the load balancer scheme used by httpd as well as how it was implemented. Check it out!

When it comes to clustering in an application server, defining the vocabulary is the first thing that needs to be done. This new article does this and much more. It defines key concepts for GlassFish such as Domain Administration Server (DAS), Node Agents, server instances, discusses deployment topologies, and explains how the Shoal and JXTA technologies are used to set up the cluster and replicate data in-memory. It also provides instructions on how to get the GlassFish "Cluster" profile running.

The second article explains how the application server can take advantage of the Zones technology built in Solaris 10 and OpenSolaris. It has a quick intro on what are Solaris zones and how they provide isolated environments for application instances. Propagation among zones can complicate installations and updates, so the article going into the details of installing and using the GlassFish application server in a global or a sparse zone. It also covers upgrading from previous versions of the software that may have come bundled with Solaris.

One of the key features in GlassFish v2 is clustering support. With greater power comes greater responsibility, so Prashanth has a detailed post on setting up and using the clustering, load-balancing and data replication features from the newly released GlassFish v2. Prashanth goes into the various options in terms of replication and load-balancing using either software (web servers) or hardware solutions. It also covers more advanced topics such as establishing a secure connection between the DAS (Domain Admin Server) and the web server. Shreedhar comments with interesting GMS/Shoal prerequisites like syncing machine clocks.

Update: The clustering features briefly described here are meant to give readers a feel for how this all works and is not intended to replace the product documentation
•  Sun Java System Application Server 9.1 High Availability Administration Guide
•  Sun Java System Application Server 9.1 Deployment Planning Guide
•  Sun Java System Application Server 9.1 HADB Commands Reference Manual.

A recent USERS thread asked about Load Balancers and GlassFish; from there and with a couple of additions: • Load Balancer Module Home Page • Daniel on Balancing with Mod_JK • Prashanth on BigIP - F5, a hardware appliance. • Sreeram and Jason on using Sun Secure Application Switch • Pankaj on using LB Plugin (which can be used with SJS Web Server) • More LB Plugin Info from Satish.

We are going to start an FAQ at the GlassFish Wiki for frequent questions like this; stay tuned.

On a different direction, one of Sailfin's improvements is integrated Load Balancer - see Milestone 1.

GlassFish is moving farther in the deployment level, with GlassFish v2's support for clustering and other enterprise-level features. A recent example of this is described by Prashanth where, triggered by questions at the JavaOne pavillion, he describes how to use a hardware appliance (Big-IP from F5 Networks) for load balancing. Prashanth's writeup is very detailed and explains how to configure Big-IP and also includes links to relevant GlassFish documents. Check it out!

It is JavaOne week and there will be many posts about the conference (and its preludes at CommunityOne) but I am going to also inject some general posts to balance it out a bit... So, talking about balancing, check out this post by Prashanth on the LoadBalancer Administration in GlassFish v2. Clustering and improved administration are part of the features in the next release, so this is very much apropos.

Now back to finishing my slides for GlassFish Day!

The GlassFish User Experience group is going through a number of topics to improve the usability of GlassFish. The meetings are open (like this one), minutes are posted, and then we hope action is taken :-).

Two weeks ago Satish presented on Load Balancing Administration (Minutes). After that he wrote two blogs describing Installing Load Balancer using the (APS) Installer and on Updating and Monitoring HTTP Load Balancer, and now has a Summarized the status of LB Administration. There is also a new Load Balancer Home Page. We hope all of this helps with Load Balancing ease of use, but send mail to the USERS mailing list if you have feedback to share.