We’ve had wonderful participation in the Red Hat Enterprise Linux 8 Beta, and if you participated in it, we hope you found the numerous related articles helpful. But whether or not you’ve tried Red Hat Enterprise Linux 8 Beta, if you’re attending Red Hat Summit 2019 next month, here are two hands-on labs you’ll want to participate in.
Continue reading Two Red Hat Enterprise Linux 8 labs at Red Hat Summit 2019: Definitive RHEL Beta, Applications Streams
Red Hat Enterprise Linux 8 Beta ships a new tool, called Image Builder, that allows you to create custom Red Hat Enterprise Linux system images in a variety of formats. These include compatibility with major cloud providers and virtualization technologies available in the market. As a result, it enables you to quickly spin up new Red Hat Enterprise Linux (RHEL) systems in different platforms, according to your requirements. At this time, Image Builder is available as a Technology Preview Feature.
In this article, we’ll show how to set up Image Builder in Red Hat Enterprise Linux 8 Beta and create a couple of images to test its capabilities. To follow this tutorial, you will need two virtual machines running Red Hat Enterprise Linux 8 Beta. We’ll not cover Red Hat Enterprise Linux 8 Beta installation in this post. For more information, take a look at Get RHEL8 Beta.
Continue reading “Red Hat Enterprise Linux 8 Image Builder: Building custom system images”
Have you tried the Red Hat Enterprise Linux 8 (RHEL8) Beta yet? Read on to learn how to stand up a LAMP stack on top of RHEL8 Beta quickly, and play around with new features built into the operating system.
A LAMP stack is made up out of four main components, and some glue. The first main component in a LAMP stack is Linux. In my example, I’m using Red Hat Enterprise Linux 8 Beta for that, which gives me a secure operating system, a modern programming environment, and user-friendly set of tools to control it.
Continue reading “How to set up a LAMP stack quickly on Red Hat Enterprise Linux 8 Beta”
I’m pleased to introduce our new Red Hat Enterprise Linux 8 Beta cheat sheet for developers.
This document is intended for those of you who are:
- Already familiar with RHEL commands, but you want a quick reference for new RHEL 8 Beta ones
- New to RHEL, and want to start exploring RHEL 8
Here’s a sample of what you’ll have access to: common module commands.
Continue reading “Red Hat Enterprise Linux 8 Beta cheat sheet for developers”
OVN (Open Virtual Network) is a subcomponent of Open vSwitch (OVS). It allows for the expression of overlay networks by connecting logical routers and logical switches. Cloud providers and cloud management systems have been using OVS for many years as a performant method for creating and managing overlay networks.
Lately, OVN has come into its own because it is being used more in Red Hat products. The result has been an increased amount of scrutiny for real-world scenarios with OVN. This has resulted in new features being added to OVN. More importantly, this has led to tremendous changes to improve performance in OVN.
In this article, I will discuss two game-changing performance improvements that have been added to OVN in the past year, and I will discuss future changes that we may see in the coming year.
Continue reading “Performance improvements in OVN: Past and future”
Diving into XDP
In the first part of this series on XDP, I introduced XDP and discussed the simplest possible example. Let’s now try to do something less trivial, exploring some more-advanced eBPF features—maps—and some common pitfalls.
XDP is available in Red Hat Enterprise Linux 8 Beta, which you can download and run now.
Continue reading “Using eXpress Data Path (XDP) maps in RHEL 8 Beta: Part 2”
With Red Hat Enterprise Linux (RHEL) 8 Beta, two major versions of Java will be supported: Java 8 and Java 11. In this article, I’ll refer to Java 8 as JDK (Java Development Kit) 8 since we are focusing on the development aspect of using Java. JDK 8 and JDK 11 refer to Red Hat builds of OpenJDK 8 and OpenJDK 11 respectively. Through this article, you’ll learn how to install and run simple Java applications on RHEL 8 Beta, how to switch between two parallel installed major JDK versions via
alternatives and how to select one of the two JDKs on a per-application basis.
Continue reading “How to install Java 8 and 11 on Red Hat Enterprise Linux 8 Beta”
XDP: From zero to 14 Mpps
In past years, the kernel community has been using different approaches in the quest for ever-increasing networking performance. While improvements have been measurable in several areas, a new wave of architecture-related security issues and related counter-measures has undone most of the gains, and purely in-kernel solutions for some packet-processing intensive workloads still lag behind the bypass solution, namely Data Plane Development Kit (DPDK), by almost an order of magnitude.
But the kernel community never sleeps (almost literally) and the holy grail of kernel-based networking performance has been found under the name of XDP: the eXpress Data Path. XDP is available in Red Hat Enterprise Linux 8 Beta, which you can download and run now.
Continue reading “Achieving high-performance, low-latency networking with XDP: Part I”
Networks are fun to work with, but often they are also a source of trouble. Network troubleshooting can be difficult, and reproducing the bad behavior that is happening in the field can be painful as well.
Luckily, there are some tools that come to the aid: network namespaces, virtual machines,
netfilter. Simple network setups can be reproduced with network namespaces and
veth devices, while more-complex setups require interconnecting virtual machines with a software bridge and using standard networking tools, like
tc, to simulate the bad behavior. If you have an issue with ICMP replies generated because an SSH server is down,
iptables -A INPUT -p tcp --dport 22 -j REJECT --reject-with icmp-host-unreachable in the correct namespace or VM can do the trick.
This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, to troubleshoot complex network issues. eBPF is a fairly new technology and the project is still in an early stage, with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8 Beta, which you can download and run now.
Continue reading “Network debugging with eBPF (RHEL 8 Beta)”
TL;DR Of course we have Python! You just need to specify if you want Python 3 or 2 as we didn’t want to set a default. Give
yum install python3 and/or
yum install python2 a try. Or, if you want to see what we recommend you install
yum install @python36 or
yum install @python27. Read on for why:
For prior versions of Red Hat Enterprise Linux, and most Linux Distributions, users have been locked to the system version of Python unless they got away from the system’s package manager. While this can be true for a lot of tools (ruby, node, Perl, php) the Python use case is more complicated because so many Linux tools (like yum) rely on Python. In order to improve the experience for RHEL 8 users, we have moved the Python used by the system “off to the side” and we introduced the concept of Application Streams based on Modularity.
Continue reading “What, No Python in RHEL 8 Beta?”