By Jacob Orshalick
The concept of conversations has been popularized recently by a rush of frameworks providing more fine-grained control over state management. The age old issue of maintaining state throughout web interactions with a user has been a constant difficulty for developers. While the HTTP Session provides a manner of maintaining state between requests for a specific user, it is shared throughout the user’s interaction with the application. This can lead to hard to debug situations as data is shared between potentially unrelated sections of the application and is a constant source of memory leaks. Conversations offer an alternative to this approach that allows state to be scoped to a unit of work and automatically handles memory cleanup when a conversation is no longer in use.
This tip article is edited and republished from the original source.
by Andrew Oliver
In Java Performance Tuning on Linux Servers, Andrew Oliver covered some general and network performance tuning issues for JEE apps running on Linux. He now looks at issues for applications in the data layer. Lower level database issues, the higher level server application persistence model, and the interactions between the two are discussed. As before, it is assumed the application is “transactional” in nature. Most web applications, including client server and business applications fall in this space. (Messaging, analytical and ETL-type applications require different strategies, and different choices).
This how-to article was edited and republished from the original source.
by Rik van Riel
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Caution |
This HOWTO is for testing purposes only. The RHEL4 Xen paravirtualized kernels are ready, but there is no installer support yet. This temporary HOWTO describes how to turn a fully virtualized RHEL4 guest into a paravirt Xen guest. Proper installation of RHEL4 guests will be available in Anaconda sometime around the end of April 2007. |
This tutorial article was originally published here.
Following on the lab tutorial teaching how to install a Xen guest, this second lab tutorial dives into live migration. It teaches you how to move an executing workload from one node to another:
Xen Live Migration (PDF, 96KiB)
This second in a series was written by Eugene Teo.
This tutorial article was originally published here.
Learn how to install various versions of Red Hat Enterprise Linux and even some other operating systems as guests in the RHEL 5 Xen virtualization environment.
Xen Guest Installation (PDF, 121 KiB)
This virtualization lab was written by Eugene Teo.
This chapter excerpt was republished from this location.
by Andrew Hudson, Paul Hudson
© Copyright Pearson Education. All rights reserved.
In This Chapter
Xen is a powerful new virtualization system that enables you to run
multiple operating systems on one computer. If you have ever used
virtualization software such as VMware or Virtual PC, you have an idea how
Xen works, except that it is faster, more powerful and, of course,
completely free.
This chapter contains an introduction to the world of Xen: how it differs
from normal virtualization solutions, how you can install it on your
Fedora machine, and how to get it configured to best suit your
environment.
This article was republished from this location.
by Rik van Riel
This is a fair, and often-heard question.
On the other side, there are virtualization fanatics, who run four virtual machines on their desktop and feel the same about virtualization as they felt about the color monitor or the sound card years ago - they can never go back to computing without it, but they can’t quite explain why somebody else should care about virtualization.
This article aims to describe why some people want virtualization, and why some other people absolutely need virtualization.
This interview is edited and republished from the original source.
A Dev Fu Interview with Andrew Overholt and Bryan Che
On 30 August 2006, Red Hat released version 3 of it’s Eclipse-based Red Hat Developer Suite of developer tools, the latest in a line of Red Hat Eclipse-based IDEs that goes back for several years. To find out more about the developer suite, what it does, how to get it, and why you’d want to we talked to Andrew Overholt, a Senior Software Engineer on The Eclipse Team, and Bryan Che, Product Manager for Developers at Red Hat. Here’s what they had to say.
This tip article has been edited and republished from the original source.
by Michael Juntao Yuan
LAMP and Java EE are two important middleware stacks for developing web applications. LAMP stands for Linux, Apache, MySQL, and PHP. They are all open source software included in Red Hat Enterprise Linux system. Java EE stands for Java Enterprise Edition. Red Hat chooses the open source JBoss Application Server (JBoss AS), which is an implementation of Java EE, as its official middleware stack.
This interview was edited and republished from the original location.
A Dev Fu Interview with Sacha Labourey
Back in April, Red Hat’s announcement of its intent to acquire JBoss began a lot of speculation about what this acquisition meant to both the companies, and to the industry as a whole. Now, three months after the transaction closed, Red Hat is announcing a combined offering of Red Hat Enterprise Linux and JBoss middleware called the Red Hat Application Stack. To find out more, we sat down with Sacha Labourey, Chief Technology Officer at JBoss, a division of Red Hat, to get his view on the Red Hat Application Stack offering and Red Hat’s acquisition of JBoss. Here’s what he had to say.
