Wednesday, February 19, 2014
Book Review for "JBoss EAP6 High Availability"
JEE servers are all about "Enterprise" functionality. A big part of the value proposition is High Availability, meaning you can harden your servers so a failure won't deprive your clients of the ability to make use of your services. This book covers High Availability for the most recent version of Red Hat's commercial server, EAP 6.
The book is written in a very clear, well-illustrated manner that explains very plainly how to achieve load balancing and failover with EAP 6. The early chapters explain how to obtain and set up the JBoss App Server, which is advantageous if you haven't looked at the server lately. (It underwent a major re-write since the old 'heavy server' days.) The methods used to deploy applications have changed too, so these are also explained.
The third chapter is where clustering begins. This leads us to the only demerit apparent for this book: it's scope is constrained to web-tier clustering. (This means other clustering aspects, like messaging clustering and EJB clustering go undescribed.) The coverage it provides within it's scope is outstanding. You are given very explicit (and easy to understand) instructions on how to test and validate your cluster.
Web-tier clustering means you need a load balancer, and this book covers two of these well. Both of these are hosted in Apache httpd, so it is also covered from acquisition, compilation, configuration and validation points of view. (To repeat that: if you know absolutely nothing about httpd, this book will show you how to get it, compile it, and run it.) Once httpd is in place, you are given detailed coverage of mod_jk and mod_cluster, two load balancers that plug into httpd. Both are described simply and thoroughly.
There are two chapters for SSL, these again give you everything you need from A to Z. The author describes certificates, how they are used, how you can produce one, and how to configure your cluster to use it. Your efforts are validated through use of tools like WireShark (naturally, we are shown how to use WireShark to do this.) There isn't much left for the user to wonder about-- thorough, well-illustrated coverage is the order of the day.
The final chapter of the book describes JEE applications that are built for clustering. Not much exciting here, JEE makes it pretty easy.
The book has a good number of illustrations. These are simple and clear, exactly the kind of thing a knowledgeable colleague might sketch on a whiteboard. Except the lines are all perfect.
The final verdict? This is a really good book. The author has a knack for explaining things clearly and directly. If you wish to cluster web applications on JBoss EAP 6, this book should be on your shelf.
The book can be found here.