Red Hat Enterprise Linux

Linux Containers combine well-established Linux kernel technologies such as namespaces, SELinux, cgroups and iptables with incredible ease of use and exceptional performance. For customers looking for the lowest possible network latencies and reduced CPU overhead coupled with the deployment advantages of Linux containers, Red Hat's new Accelerating Red Hat Enterprise Linux 7-based Linux Containers with Solarflare OpenOnload whitepaper provides installation, configuration and tuning guidance for Docker containers running on Red Hat Enterprise Linux with Solarflare OpenOnload network acceleration. The whitepaper...

In an earlier post, I talked about GCC (the GNU Compiler Collection), and work that I did to make the internals of GCC more robust for GCC 5. This post is about something more user-visible: as of GCC 5, GCC's code-generation backend can now be built as a shared library. When might you want to generate machine code? The primary reason is for speed: anything that parses an input format and repeatedly acts on it, such as language interpreter, or...

Now entering it's third year, the Red Hat Developer Toolset (DTS) is once again available for beta testing of a new point release, version 3.1. If you are unfamiliar with DTS, see Matt Newsome's (engineering lead) original introduction. Red Hat Developer Toolset 3.1 includes the latest, "stable open source C and C++ compilers and complementary development tools. Bridging developer productivity and production stability, Red Hat Developer Toolset 3.1 Beta is available through the Red Hat Enterprise Linux Developer Program and...

Backstory Red Hat's Performance Engineering team is responsible for the performance of many of Red Hat's products. We cover existing products such as RHEL, OpenStack Platform, OpenShift and RHEV, as well as newer products like Ceph and CloudForms. Although these days we contribute extensively to Red Hat's cloud offerings, Red Hat Enterprise Linux remains a core responsibility as the building block for our large ecosystem of customers and partners, plus much of Red Hat's growing product portfolio. Smoketest Surprise Some...

Here are excerpts from today's announcement - an ecosystem with container development tools to containerize and certify applications: "Red Hat today announced the launch of the first certified, end-to-end ecosystem program for Linux containers based on Docker, a key component of the company’s vision for containerized applications unveiled in March 2014. Leveraging Red Hat’s vast network of thousands of partners and independent software vendors (ISVs), this ecosystem program is designed to enable the design, development and delivery of certified, trusted...

The rise of the purpose-built Linux distribution Recently, several purpose-built distributions have been created specifically to run Linux containers. There seem to be more popping up every day. For our part, in April 2014 at the Red Hat Summit, Red Hat announced its intention to deliver a purpose-built, container-optimized version of Red Hat Enterprise Linux 7 called RHEL Atomic Host. After over a year in the making, we are excited that launch day has finally come! What's important to know...

White box testing? Traditional white box testing verifies the internal implementation details of the software under test. As of today the GNU C Library (glibc) has very little if any white box testing. The general policy has been that we implement standards conforming interfaces and that as such we need to test those interfaces. This is a good start, but we need to test more if we are going to cover all cases and configurations, and this includes more detailed...

Red Hat "has announced the general availability of Red Hat Enterprise Linux 7 Atomic Host, an operating system optimized for running the next generation of applications with Linux containers." "Based on RHEL, Red Hat Enterprise Linux Atomic Host enables enterprises to embrace a container-based architecture to take advantage of the benefits of development and deployment flexibility and simplified maintenance, without sacrificing performance, stability, security, or the value of Red Hat’s vast certified ecosystem. "For building and maintaining container infrastructure, Red...

This article was written by Red Hat's Siddharth Nagar, RHEL 7 product manager. "As product manager for Red Hat Enterprise Linux 7, part of my job is to ensure that the latest version of our flagship product adheres to our promise of stability, reliability, and security. In addition, as Red Hat Enterprise Linux 7 is Red Hat’s latest enterprise Linux platform, it also needs to incorporate new innovations in technology to help our customers gain business advantage, reduce costs, and...

If you are paying close attention to the growing 64-bit ARM ecosystem you may have already seen yesterday’s press release announcing several milestones for the Red Hat ARM Partner Early Access Program, that was announced in July of last year. While the release talks about the program at a high level, there are several takeaways that may affect the developer community in the near future. Fundamentally, the ARM Partner Early Access Program was launched to benefit hardware and software vendors...

Counting micro-nanoseconds? We are, because we know our customers are. Some of the world's largest stock exchanges including the Chicago Mercantile Exchange (CME), New York Stock Exchange (NYSE), E*TRADE, Union Bank, countless hedge funds and high-frequency trading shops run on Red Hat's products. In fact, the majority of the world's financial transactions are executed with Red Hat Enterprise Linux in the critical path. This encompasses some of our industry's most mission-critical, performance-sensitive workloads. We appreciate that the operating system needs...

"Even bad code can function. But if code isn’t clean, it can bring a development organization to its knees" -- Clean Code We spent 10 times more time reading code than writing it. Thus keeping code clean is essential for maintainability and company growth, but doing it by hand can be tedious. Let's take a look at some of the clean code practices and how we can use Eclipse to re-factor code faster. Change inline comments to sub method calls...

Last time we discussed de-duplicating some code. Today let us look into the effectiveness of refactored code, Java 8 support and moving/renaming code. But hold on, aren't method calls expensive? I took a course on compilers in University and did some research on the matter. In 1996 Java in-lining might have made sense. But nowadays the overhead that methods generate is relatively negligible, also the JVM is quite smart in optimizing bytecode by in-lining methods that make sense to in-line...

The GNU C++ team works hard to avoid breaking ABI compatibility between releases, including between different -std= modes. But some new complexity requirements in the C++11 standard require ABI changes to several standard library classes to satisfy, most notably to std::basic_string and std::list. And since std::basic_string is used widely, much of the standard library is affected. Many users routinely rebuild all their code when they change compilers; such users will be unaffected by this change. Code built with an earlier...

What is rebase-helper used for? Rebase-helper automates a lot of manual tasks when a new upstream version of a package is released. How to install rebase-helper on RHEL 7 system? Use this COPR repository where RPM package is already created. http://copr-fe.cloud.fedoraproject.org/coprs/phracek/rebase-helper_EPEL/ Download the repo file and install rebase-helper via yum command. yum install rebase-helper Rebase-helper performs several tasks during the rebase: Downloads an archive with the new sources Tries to apply all downstream patches: If a patch does not apply...

Not too soon after people start using Atomic images, the question of customization soon follows. It is a natural progression for most people when they use Atomic. There are a number of different ways to accomplish using custom images not withstanding using docker and containers. The Atomic tool called ' rpm-ostree-toolbox' is emerging as the best tool for customizing Atomic. The 'rpm-ostree-toolbox' main command is actually a wrapper (much like virsh) for three subcommands: treecompose, imagefactory, and installer. With these...

Have you wanted to use software collections but found packaging has kept you at bay? Tried rebuilding a package only to find it give you weird errors you've not seen before? In this blog post we'll learn how to configure and use mock to build RPM packages for the Python 2.7 Software Collection. Along the way we'll learn why we can't use standard mock configurations, and what makes Software Collections (SCL) mock configurations different. For readers unfamiliar with mock, I'll...

One feedback I got from my blog post on Understanding malloc behavior using Systemtap userspace probes was that I should have included an example script to explain how this works. Well, better late than never, so here's an example script. This script prints some diagnostic information during a program run and also logs some information to print out a summary at the end. I'll go through the script a few related probes at a time. global sbrk, waits, arenalist, mmap_threshold...

Use cases In Red Hat Enterprise Linux we support a variety of different versions of PHP. Sometimes users find they need to run a legacy application, requiring an older version of PHP, on a newer version of RHEL. Developers may want to develop an application on their Fedora Workstation and deploy it on a RHEL server or ensure it will be compatible with all available PHP versions in enterprise distributions. This example can be easily adapted for all PHP versions...

This is a continuation to The ARM Arc Part 1 published in July. It all started in 2012 when the Fedora ARM community decided to move from the legacy ARMv5 software floating point ABI to the new ARMv7 hard float ABI. The move meant better performing code, native atomic operations, threading support, and other modern OS features becoming available to ARM software developers on a general purpose OS. Doing the work required a way to bootstrap a new architecture, which...

Earlier this year I was asked to bootstrap our core tools (compiler, assembler, linker, and libraries) from the ground up, to help the rest of the team in providing enough infrastructure for bootstrapping an entire OS to POWER8 little endian. Since I spend most of my days working on the upstream development of the GNU Compiler Collection (GCC), prior to this project I hadn't actually worked much with either RHEL's development processes or RPM as a whole. So leading our...

I like to work with open source code. But it is not always possible. Sometimes you have to deal with proprietary code. And sometimes you have to distribute it. I like to distribute software as RPM package because it allows me to put together patches, post-install scripts and configuration files. But how can I create and distribute proprietary software without violating license? The answer is " nosrc.rpm". For example - let assume that you want to distribute Oracle Database Server...

As Software Collections are getting popular, there are more and more people asking how they can build their own collections and/or extend collections in RHSCL. In this article, I will demonstrate how to extend python27 collection from RHSCL 1.2, adding a simple Python extension library. (Note that the same steps can be applied to the python33 collection.) I'm going to work on a RHEL 6 machine throughout this whole tutorial. I'm assuming that readers have basic knowledge of RPM building...