One of our long-time writers introduced us to Jaroslaw, a JBoss QA Engineer based in Poland, and mentioned that he’d been working on some documentation we might find interesting. And, boy, do we! This first piece de-mystifies the complex world of rules engines. Whether you call it Drools, or JBoss Rules, or JBoss Drools… you still might want to know what it does and how it functions in your technical environment. (Not to mention that it’s just all kinds of logical and interesting–if you like brainteaser word puzzles or abstract math questions, this qualifies as pleasure reading.)
This article is presented here in its entirety (with a trackback). The original can be found on Jaroslaw’s site. This article is also available in German and Polish.
Either you’re a developer, architect or a business analyst, it’s worth to get familiar at least with the first chapter of this article. It contains an introduction into the world of rule engines, which increase the readability of certain applications and make them easier to manage and to maintain. It applies to apps that take decisions, which depend on events or a state of some objects.
This article contains an introduction to rule engines, a description of an installation of Eclipse IDE and a guide how to configure Eclipse with the Drools Workbench plug-in. » Read more
This article is a follow-up to Red Hat Enterprise Linux 5.1 utilizes nested paging on AMD Barcelona Processor to improve performance of virtualized guests.
With new hardware releases, customers are faced with situations in which they want to take advantage of increased speeds but are forced to stay on older hardware because their operating environments are not supported on the newer hardware. Virtualizing their operating environment helps them get past this issue. Virtualization also helps them:
RHEL 5 virtualization lets customers virtualize their existing systems and take advantage of the benefits mentioned above. » Read more
Last month, I wrote about confining the user with SELinux. I explained that–as of Fedora 9–SELinux supports the concept of the confined user and comes with 5 confined user types defined.
These confined users are a great starting point, but what if you want to create a confined user with different privileges? » Read more
As computers become more and more powerful, as IT shops invest on reducing costs, as we become more and more energy efficient, it seems that nothing can go wrong with virtualization.
Red Hat Enterprise Linux allows the choice of two types of virtualization: full virt and paravirtualization. The difference is whether the guest operating system knows it is virtualized. Under a fully virtualized environment, there is a total abstraction of the hardware needed to run the guest OS. » Read more
by Steve “Ashcrow” Milner and Anderson Silva
In today’s world, web development is all about turnaround. Businesses want to maximize production outcome while minimizing development and production time. Small, lean development teams are increasingly becoming the normal large development departments. Enter Django: a popular Python web framework that invokes the RWAD (rapid web application development) and DRY (don’t repeat yourself) principles with clean, pragmatic design.
The phone rings. You pick it up, and it is the recruiter for your dream job. Your palms begin to sweat as the technical interview starts.
“You want to know the run-levels for Red Hat® Enterprise Linux® or Fedora®?” You pause, thinking. “Well, I use Linux every day, and I know single user mode is level 1…”. You stammer a bit, and say you’re drawing a blank for the rest. The recruiter thanks you in that “sorry” tone-of-voice, and hangs up the phone.
Let’s cross that question off the recruiter’s list forever. (Sorry, recruiters.) In this article, we cover how to create, use, modify, and ultimately master run-levels. Bookmark this page with your favorite bookmarking service, and rest easy about ever missing that interview question again.
Of course, there are more reasons to know about run-levels than just to pass an interview. Interacting with run-levels is quite useful once you get used to it. In this article we are going to cover the basics, and then go beyond that to create our own run-level that we write a script against. » Read more
To find the label of a partition, use this command:
# blkid -s LABEL /dev/
Replace with the name of the swap partition.
This command will also work with any other type of partition
One of the joys of software development is the ease with which you can create complex stuff out of thin air–or your own imagination. Creating new software may fulfill a need that could not otherwise be met. However, you can take advantage of a standardized way of doing things, so that you don’t have to start from scratch every single time. In the case of infrastructure software, using an established standard enables you to concentrate on your specific business needs, and not the supporting systems.
The seed of this article is actually a comment on the first article[1] in this series. In that first article, I described middleware as though it were plumbing. I chose to use this analogy as the term “middleware” is often misunderstood. My rationale for the plumbing analogy was that plumbing and middleware share these characteristics:
First, it’s mostly invisible. Second, it provides a standard way of doing things. Third, it ties together parts of complex systems. Fourth, and finally, it lets you worry about other things. » Read more
Contributing writer: Thomas Fitzsimmons
At the 2006 JavaOne conference, Sun announced plans to open source Java. This wasn’t exactly a surprise to those of us working on Java at Red Hat, given that there had been rumblings before. But this was a real announcement. We were immediately interested in learning exactly which license Sun would choose. Even if it was a legitimate open source license, it still might not allow us to combine our code with Sun’s.
We have been working on free Java for many years–most particularly through gcj, a project started at Cygnus in 1998 by a developer named Per Bothner. Gcj has been steadily improving over the years, but still wasn’t fully Java-compatible, partly because we couldn’t get permission to run the official Java compatibility test suite. We had also been working on GNU Classpath, which is GNU’s free replacement for the core Java class libraries from Sun. We were very curious to see the “official version.” » Read more
Hello, Red Hat Network Satellite users! We hope you’re excited about the recent release of Red Hat Network Satellite 5.1. Earlier, we gave you some details about the new Satellite exporter tool that allows you to easily populate content on disconnected RHN Satellites.
Another new feature introduced by Satellite 5.1 is multiple organization support. This feature allows you to partition your Satellite into different organizations, each with their own subscriptions, systems, and content. It provides Satellite administrators with a new way to control user and system access to resources on a Satellite server. For more details on multiple organization support, please refer to our whitepaper: RHN Satellite 5.1 Best Practices for Multiple Organizations (PDF download, ~700KB).
The Satellite Team would like to learn how we can improve this feature to better suit your needs–and we need your help. » Read more
