Linux

(Photo credit by Crystalline Radical) Nowadays, while most people in our industry know about DVCS tools, such as Git and Mercurial, and what they can do, not all are aware that git can be used with SVN. It is, of course, quite a shame as on top of being the best way to learn how to use git - this feature also enables one to use all the nice tricks of DVCS (offline commit, local history rewriting, commit search, bisect...)...

Some months ago, I developed and released a small Puppet module for tuned-adm. As this tool is a nice feature of RHEL, I think it is only fair from me to advertise about it here, on the Red Hat developer blog. Quick overview of 'tuned-adm' (Photo credit: Accretion Disc) To make this brief, this command will take care of tuning the operating system for you, based on the usage you want to make of it. For instance, if you want...

The day before Red Hat Summit in Boston, we hosted a Red Hat Developer Exchange day - a one day technical event which covered some great topics across four tracks: DevOps, Programming on OpenShift, Languages and Tools, and Get more out of Red Hat Tools. The feedback on these was consistently great, so we hope you find them useful too! Track: DevOps DevOps in the Enterprise Choosing the Right Cloud Platform for You Monitoring and Metering: Baking Operational Goodness into...

As I mentioned here, Joe Mario and I delivered this session at Red Hat's Developer Exchange session in Boston. There were a lot of great questions and we hope you'll find this video-recorded session useful. Abstract: Now that you followed all the steps to make your application NUMA-aware, how do you know if you got it right, or if you shifted your performance problem elsewhere? In this session, Don and Joe will: discuss initial high level steps to verify correct...

A couple of months ago, Red Hat announced the beta 1 phases of both Red Hat Developer Toolset V2.0 and Red Hat Software Collections V1.0. Now, they are both in a beta 2 phase! Be sure to take a look at these tools if you haven't already - we've receive a huge amount of interest in them! Both offerings provide recent, stable versions of technologies that you've been asking for. At a high level, Developer Toolset is for gcc and...

If you have ever worked as a system administrator, you are familiar with developers constantly wanting to use the latest toolchains even to the point of wanting to roll their own packages. Of course, the challenge is, if you are running a production environment, introducing change is always risky. If the change being introduced is from an unknown source, the risk is even higher. As a result, many admins rely on companies like Red Hat to provide them some assurances...

As I discussed in an article entitled Red Enterprise Linux Release Speed, developers sometimes have a problem with how slow Red Hat's Enterprise Linux releases new versions of software. Well, the good news is, Software Collections are here. Software Collections provide Red Hat Enterprise Linux users with newer versions of programming languages and server daemons like python, perl, ruby, php, mysql, mariadb, etc. This is a quick start guide to help you get comfortable with both programming languages and server...

In order to test out the new Red Hat Software Collections (RHSCL, announcement) version of PHP 5.4, I decided to build out a Drupal 7 install using the php54 collection and the mysql55 collection. Overall, the activity was pretty much like a normal Drupal install. However, to use software collections you have to do a few things differently. Also, if you haven't used a software collection for a "service" (e.g. MySQL) before, the service setup is also a little different...

Official announcement : Red Hat Software Collections 1.0 Beta Now Available More information on Software Collections Software Collections Guide Stability addicts can keep quiet, PHP 5.3.3 is still the standard version provided with RHEL-6. We'll soon have an official and supported way to install PHP version 5.4, beside the system version, without any effect on installed components. The announcement tells us the life cycle will be 3 years. Warning: it's a beta version, published for evaluation purposes. Installation Activation of...

OpenStack is picking up a lot of steam these days, but getting it installed can be a hassle. Lots of puppet-based installers have popped up to automate this arduous task. Using Foreman, however, administrators can not only configure and install OpenStack using puppet, but provision & add new compute nodes at their fancy. The Foreman is a Ruby on Rails application that does configuration management with puppet and provisioning. We'll use both of these features to make using & administering...

This article will show you how to use two software collections of RHSCL 1.0 Beta for cutting edge development. We will create a Django 1.5 application (running on Python 3.3), that will use PostgreSQL 9.2 as a database. Installing Dependencies First off, we will install the required collections. If you haven't done so already, you need to subscribe to the correct RHN channel ( rhel-x86_64- variant-6-rhscl-1-beta, where variant is one of server, client or workstation). Now you should be able...

You may have seen references to " software collections" in this blog, but this is different. "Red Hat Software Collections", now in beta for the first time, is a collection of refreshed and supported web/dynamic languages and databases for Red Hat Enterprise Linux. Now you can have two versions of software on one OS, or refresh these languages and databases more frequently. See this list below! From the announcement: "Red Hat is pleased to announce the Beta release of Red...

A common performance related issue we are seeing is how certain instructions are causing bottlenecks. Sometimes it just doesn't make sense. Especially when it involves lots of threads or shared memory on NUMA systems. For quite awhile a bunch of us have been writing tools to help exploit features of the CPU to provide us insight to not only the instruction of the bottleneck but the data address too. See, the instruction is only half the picture. Having the data...

One common idiom in performance monitoring is how long did it take for a program to do something. For example you may want to know the time taken for database queries in PostgreSQL or just-in-time translations in a Java Virtual Machine. SystemTap and user-space markers in Linux packages make it much easier to determine the duration of those operations. The user-space markers compiled into Linux packages mark key points in the code where particular actions occur. The user-space markers also...

Red Hat has actively participated in the ISO group defining the C++ standard for many years, and continues to make a significant contribution. The Red Hat toolchain team was well-represented at the spring meeting of the standardization committee (technically JTC1/SC22/WG21) in Bristol, UK, last month: we had three people there for the full week, with one other visiting a couple of times during the week. In this article, Jason Merrill summarizes the main highlights and developments of interest to Red...

RPM Package Manager (RPM) was created to deliver software to workstations and servers. Besides being an efficient software delivery mechanism, RPM also provides security features that assist system administrators with managing their software and trusting the code that is going into their infrastructure. What is an RPM? RPM is a package management system that bundles software source code or binaries together for easy installation on a computer. These files are tracked and allow for easy installation, upgrading, and removal. Since...

WebSockets are a rising technology that solves one of the great needs of web development - full duplex communication between a browser (or a different client) and a server. Let's imagine a simple scenario - live web chat. In the past, you'd probably use AJAX and polling to make new posts appear in realtime. The downside is that implementing all that is not entirely easy and it tends to put a lot of strain on the server. This article will...

As I stare at this blank screen to start writing my first blog entry I have that same feeling that so many developers have when starting with an unfamiliar programming language or application. The developers in our group realize that it is not easy starting from nothing and we strive to make it easier to productively use SystemTap to investigate performance problems. A starting point for anyone's first use of SystemTap is the SystemTap Beginners Guide on the Red Hat...

Unfortunately, not every application is packaged for every distribution. What do you do when you can't find it packaged for Red Hat Enterprise Linux? If you are like most people, you give up or attempt to install it from source. What happens when installing from source goes badly? If you are like most people, you definitely give up. How do you keep up with application improvements or, perhaps more importantly, security fixes? If you are like most people, you periodically...

This technical article covers a subtlety in C++ array allocation and how we changed the GNU C++ compiler to deal with it properly. When a programmer writes T *p = new T[3]; the C++ compiler allocates room for at least three copies of objects of type T on the heap. These objects require 3 * sizeof(T) bytes. For this example, assume sizeof(T) is 12, then it is straightforward to allocate 36 bytes (for example, using malloc). But what happens if...

While Red Hat Enterprise Linux is known for its stability and flexibility, you might not think of it first when looking for the latest version of your web application framework. If you're a developer working with Ruby and Ruby on Rails, you probably want to take advantage of their new features. Sure, you can use RVM, but sometimes you just want to get supported system packages. Software Collections (often abbreviated as SCL) allows you to run more recent versions of...

Did you ever wish you had newer versions of the software on your Red Hat Enterprise Linux machines? You are probably not alone. Providing new versions of software in rpm is hard, because rpm supports only one version installed on your computer at a time. Multiple versions on one machine can conflict with each other or create unpredictable behaviour in applications that you might not have considered dependencies. Last year, we developed Software Collections to allow you to install newer...