Red Hat Enterprise Linux

PHP 7.2, Node.js 10, NGINX 1.14 and others now GA for RHEL

We are pleased to announce general availability Red Hat Software Collections 3.2, which adds these components to Red Hat Enterprise Linux 7:

  • PHP 7.2
  • Varnish Cache 6.0
  • MySQL 8.0
  • NGINX 1.14
  • Node.js 10
  • Git 2.18
  • Update of Apache HTTP server 2.4

These versions are available on Red Hat Enterprise Linux 7 (Devtools or RHSCL channel) for x86_64, s390x, aarch64, and ppc64le.  Read more details about each component in the “New Components details” section.

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Clang/LLVM 6.0, Go 1.10, and Rust 1.29 NOW GA for RHEL

Clang/LLVM 6.0, Go 1.10, and Rust 1.29 NOW GA for RHEL

We are pleased to announce general availability of these 3 compiler toolsets for Red Hat Enterprise Linux 7. These versions are now officially supported Red Hat offerings:

  • Clang/LLVM 6.0
  • Go 1.10
  • Rust 1.29

These toolsets can be installed from the Red Hat Enterprise Linux 7 Devtools channel.  See the “New compiler details” below to learn about the new features.

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Improved support information for RHEL on Azure: sosreport plugin updated

Improved support information for RHEL on Azure: sosreport plugin updated

Red Hat Enterprise Linux has a tool called sosreport that improves the ability to get support by collecting accurate current details of system information, configuration, and diagnostic information. The “sos” command is an excellent point to start the investigation when your system has an issue. In addition, the file generated by sosreport is usually a starting point when a Red Hat support engineer investigates. Even if you’re not an administrator but a developer, the sosreport is easy to use.  Just type “sos“ using sudo or as root.

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Reducing the startup overhead of SystemTap monitoring scripts with syscall_any tapset

Reducing the startup overhead of SystemTap monitoring scripts with syscall_any tapset

A number of the SystemTap script examples in the newly released SystemTap 4.0 available in Fedora 28 and 29 have reduced the amount of time required to convert the scripts into running instrumentation by using the syscall_any tapset.

This article discusses the particular changes made in the scripts and how you might also use this new tapset to make the instrumentation that monitors system calls smaller and more efficient. (This article is a follow-on to my previous article: Analyzing and reducing SystemTap’s startup cost for scripts.)

The key observation that triggered the creation of the syscall_any tapset was a number of scripts that did not use the syscall arguments. The scripts often used syscall.* and syscall.*.return, but they were only concerned with the particular syscall name and the return value. This type of information for all the system calls is available from the sys_entry and sys_exit kernel tracepoints. Thus, rather than creating hundreds of kprobes for each of the individual functions implementing the various system calls, there are just a couple of tracepoints being used in their place.

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How to create an Open Virtual Network distributed gateway router

How to create an Open Virtual Network distributed gateway router

In this article, I discuss external connectivity in Open Virtual Network (OVN), a subproject of Open vSwitch (OVS), using a distributed gateway router.

OVN provides external connectivity in two ways:

  • A logical router with a distributed gateway port, which is referred to as a distributed gateway router in this article
  • A logical gateway router

In this article, you will see how to create a distributed gateway router and an example of how it works.

Creating a distributed gateway router has some advantages over using a logical gateway router for the CMS (cloud management system):

  • It is easier to create a distributed gateway router because the CMS doesn’t need to create a transit logical switch, which is needed for a logical gateway router.
  • A distributed gateway router supports distributed north/south traffic, whereas the logical gateway router is centralized on a single gateway chassis.
  • A distributed gateway router supports high availability.

Note: The CMS can be OpenStack, Red Hat OpenShift, Red Hat Virtualization, or any other system that manages a cloud.

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Locating special folders in cross-platform .NET applications

Locating special folders in cross-platform .NET applications

.NET has APIs for locating special folders that can be used for application and user configuration and data storage. They provide a convenient, portable way to make cross-platform applications find the appropriate folders on different operating systems. We’ll look at how Environment.GetFolderPath, Path.GetTempPath, and Path.GetTempFileName behave on Linux.

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Migrating from Oracle JDK to OpenJDK on Red Hat Enterprise Linux: What you need to know

Migrating from Oracle JDK to OpenJDK on Red Hat Enterprise Linux: What you need to know

Oracle has announced that the Oracle JDK 8 builds released after Jan 2019 cease to be free for commercial use. GPL + Classpath Exception licensed (free for any use, subject to that license) are current made available by Oracle through http://jdk.java.net/11/. (See also Oracle’s blog entry & licensing).
An alternative is to use OpenJDK and effort is underway to make them fully interchangeable. A number of companies who are currently using Oracle JDK in production are making the decision to switch to OpenJDK or have already done so.

Andrew Haley (Red Hat’s Java Platform Lead Engineer) recently wrote a great article on the direction of OpenJDK.

In this article, I’ll discuss: the technical and support implications of the migration, what developers and operations teams need to know, and solutions to potential challenges.

I’ll go over the Red Hat support model and technical details of how to install, update, and run different OpenJDK versions on Red Hat Enterprise Linux (RHEL) 6 and 7 systems. I’ll also discuss the operations of Java applications (such as Red Hat JBoss Enterprise Application Platform (JBoss EAP) and other servers) on top of OpenJDK.

While this article is about OpenJDK on RHEL, I should also point out that OpenJDK for Windows can also be downloaded from developers.redhat.com. This lets you use the same JDK for Linux and Windows.

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How to manually copy SSH public keys to servers on Red Hat Enterprise Linux

How to manually copy SSH public keys to servers on Red Hat Enterprise Linux

We often use ssh-copy-id to copy ssh keys from our local Linux computers to RHEL servers in order to connect without typing in a password. This is not only for convenience; it enables you to script and automate tasks that involve remote machines.  Also, using ssh keys correctly is considered a best practice.  If you are conditioned to respond with your password every time you are prompted, you might not notice a prompt that isn’t legitimate (for example, spoofed).

What about when you can’t use ssh-copy-id or the target user ID doesn’t have a password (for example, an Ansible service user)? This article explains how to do it manually and avoid the common pitfall of forgetting to set the proper permissions.

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Analyzing and reducing SystemTap’s startup cost for scripts

Analyzing and reducing SystemTap’s startup cost for scripts

SystemTap is a powerful tool for investigating system issues, but for some SystemTap instrumentation scripts, the startup times are too long. This article describes how to analyze and reduce SystemTap’s startup costs for scripts.

We can use SystemTap to investigate this problem and provide some hard data on the time required for each of the passes that SystemTap uses to convert a SystemTap script into instrumentation. SystemTap has a set of probe points marking the start and end of passes from 0 to 5:

  • pass0: Parsing command-line arguments
  • pass1: Parsing scripts
  • pass2: Elaboration
  • pass3: Translation to C
  • pass4: Compilation of C code into kernel module
  • pass5: Running the instrumentation

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GCC 8 and tools now in beta for Red Hat Enterprise Linux 6 and 7

GCC 8 and tools now in beta for Red Hat Enterprise Linux 6 and 7

We are pleased to announce the immediate availability of Red Hat Developer Toolset 8 beta for Red Hat Enterprise Linux 6 and 7.  The key new components for this release are:

  • GCC 8.2.1
  • GDB 8.2
  • Updated components such as SystemTap, Valgrind, OProfile, and many more

Like other tools, these are installable via yum from the Red Hat Enterprise Linux 6 or 7 Devtools or RHSCL channel.  For more details, see the “New Features” section below.

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