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Stack Clash Mitigation in GCC -- Background

Jeff Law

It has long been recognized that unconstrained growth of memory usage constitutes a potential denial of service vulnerability. Qualys has shown that such unconstrained growth can be combined with other vulnerabilities and exploited in ways that are more serious. Typically, the heap and stack of a process start at opposite ends of the unused address space and grow towards each other. This maximizes the flexibility to grow the regions over the course of execution of the program without apriori knowing...

VLAN filter support on bridge
Article

VLAN filter support on bridge

Hangbin Liu

This blog aims for Administrators who need to handle large numbers of VLANs in virtualization/namespaces with a bridge. With the VLAN filter, people don't need to create dozens of VLANs and bridges anymore. With only ONE bridge, you can control all VLANs. See more details in this blog. Bridge and VLAN Virtualization, Cloud, OpenStack, and Docker. These technologies are getting increasingly important and popular. But behind them, there are two indispensable features: Bridge and VLAN. A bridge is a way...

RESTful API
Article

Know how RESTful your API is: An Overview of the Richardson Maturity Model

Rahul Kumar

Most of the time, I see developers are bit confused about the term REST. For some enterprise application developers, the meaning of REST is JSON i.e. if they are using JSON in their application, which means they working on REST API, which is not true to some extent. Let's take a look what exactly a REST API is. Let's say we designed a REST API. How do we know how much Restful API is? Some developers call it "Not Restful...

.NET Core
Article

Using .NET Core 2.0 and RHEL in Linux Containers

Don Schenck

.NET Core 2.0 represents the maturation of the .NET Core development effort. This, the third release (previous releases being version 1.0 and 1.1), brings nearly 20,000 more APIs and a much richer and deeper developer experience. To put it in the vernacular, .NET Core is ready for prime time. This blog post will show you the critical steps and configurations necessary to use .NET Core 2.0 running on RHEL inside your Linux containers. The Challenge Beginning with .NET Core 2.0...

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On link modeling, network emulation and its impacts on applications

Marcelo Ricardo Leitner

In this blog post, I’ll guide you through the most important characteristics that define a 'link' in packet-switched networks, how they can impact your application, give some examples of real world parameters and how to use NetEm to emulate them. In every packet-switched network, you will notice characteristics that are intrinsic to them and that varies depends on the communication channels being used. Such characteristics are bandwidth, delay (including jitter), packet loss, packet corruption and reordering. Bandwidth probably is the...

Using API keys securely in your OpenShift microservices and applications
Article

Gluster for OpenShift - Part 1: Container-Ready Storage

davis phillips

OpenShift Container Platform (OCP) offers many different types of persistent storage. Persistent storage ensures that data should be insistent between builds and container migrations. When choosing a persistent storage backend to ensure that the backend supports the scaling, speed, dynamic provisioning, RWX/RWO support and redundancy that the project requires. Container-Ready Storage (CRS), or native Gluster for OCP, is defined by the concept of persistent volumes, which are OCP created objects that allow storage to be defined and then used by...

.NET Core
Article

Introduction to NuGet with .NET Core on RHEL

Dave Mulford

Introduction to NuGet with .NET Core NuGet is an open source package manager for the .NET Core ecosystem. For those familiar with Red Hat Enterprise Linux (RHEL), you can think of it as the “yum” for pulling libraries into your .NET Core project. Working with NuGet packages in .NET Core applications is accomplished primarily through your project’s .csproj file and the dotnet command-line interface. Repositories Just like RHEL, NuGet has its own repositories to get packages. By default, when the...

Configuring mKahaDB persistence storage for ActiveMQ
Article

Red Hat Releases New Development Tools

Bob Davis

I’m extremely pleased to announce the latest releases of our Red Hat developer tools, available on multiple platforms. The general theme of this release is expanded usability, product integration, expanded support for Middleware products in Development Suite, plus the brand new addition of Kompose and the DevTools channel for Red Hat Enterprise Linux. This collection of tools has been assembled into an easy-to-use installer to help software developers quickly and easily put together a development environment to create containerized enterprise...

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Announcing Red Hat Developer Studio 11.0.0.GA and JBoss Tools 4.5.0.Final for Eclipse Oxygen

Jeff Maury

JBoss Tools 4.5 and Red Hat JBoss Developer Studio 11.0 for Eclipse Oxygen are here waiting for you. Check it out! Installation JBoss Developer Studio comes with everything pre-bundled in its installer. Simply download it from our Red Hat Developers and run it like this: java -jar jboss-devstudio-.jar JBoss Tools or Bring-Your-Own-Eclipse (BYOE) JBoss Developer Studio requires a bit more: This release requires at least Eclipse 4.7 (Oxygen) but we recommend using the latest Eclipse 4.7 Oxygen JEE Bundle since...

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Install .NET Core on RHEL in under 5 minutes, by Don Schenck.

Don Schenck

A lightning talk from Red Hat Summit 2017. Here is the transcription:

[00:11] I have a VM here. Let me just run the .NET command to show you. It's not there, so we're going to install .NET on RHEL. The first thing I'm going to do is become Super User, otherwise I have to type pseudo for every command and that's just a hassle.

[00:33] I'm just going to copy and paste the commands here. The point isn't that I type out every command, the point is that you see it's only a couple of commands to get it installed. The first thing I'll do is get my subscription manager attached to the correct pool of RPMs, that's the packages I pulled down.

[00:49] When you install .NET on RHEL you're getting the package from Red Hat. You're not getting it from Microsoft. We get the source code from Microsoft and then we build it to run on RHEL. Red Hat packages are, I like to say vetted. That is, we test them and make sure they work really well so you're not just pulling down software and hoping it works.

[01:12] Now I'm going to enable the repo. I've attached to it and now I have to enable it. Notice at the end where it says, "RHEL 7 Server..." There's also a work station, and there's also one for an HP [high performance] special computing thing that I'm not really familiar with. The point is you're probably going to use a RHEL server to install .NET.

[01:26] One of the cool things about the new .NET core as opposed to the old one is the new .NET is much smaller. Whereas before, when you installed .NET, you would drop in a DVD, or a CD, and wait forever for it install, and you would get 4 gigabytes of .NET. Now it's just a couple hundred megabytes.

[01:49] I'm going to YUM install this scl utils. It doesn't matter what they do. They just enable installation. Let's just leave it at that. There's nothing to do because I've done that before, but that's OK. It's better to have nothing to do than to skip the step.

[02:08] Now here's the actual install itself. I want you to notice it's just a command line and it's a YUM installed .NET core 1.1, which is version 1.1. It's going to go up to the inner webs and pull down everything it needs to install it.

[02:17] Your limiting factor here is going to be your Internet speed. Other than that, that's it for installing .NET. It really is that small and that fast. After it's installed, you have to enable it to be available in Bash. Once that's done, we'll bring it up and we'll see .NET.

[02:36] One final step here. In just a few minutes we went from not having .NET...I don't know if I can copy and paste here, bear with me.

[02:47] It's enabled. Now we should have .NET command available. There it is. We'll do a .NET new which will create a new program. The first time you do a .NET new it's going to run this little expand. That might be considered the final step of installing .NET, that's it. That's all you have to do to install .NET, that's it.

Thank you.

MACsec setup with NetworkManager
Article

What's new in MACsec: setting up MACsec using wpa_supplicant and (optionally) NetworkManager

Sabrina Dubroca

A few months ago, on this blog, we talked about MACsec. In this post, I want to introduce the work we've done since then. Since that work revolves around methods to configure MACsec, this will also act as a guide to configure it by two methods: wpa_supplicant alone, or NetworkManager with wpa_supplicant. If you read the previous MACsec post, you probably thought that this whole business of generating keys and creating "secure associations" isn't very convenient, especially given that you...

QinQ Performance
Article

Open vSwitch: QinQ Performance

Eric Garver

In a previous post, we introduced QinQ support for Open vSwitch. This post will investigate how QinQ performs relative to alternatives (VXLAN, GENEVE) in both throughput and CPU utilization. This will give us some understanding why we might consider QinQ over VXLAN or GENEVE. We're going to look at the following tunnel types and configurations: VXLAN-SW VXLAN in software only. No hardware offload. VXLAN-HW VXLAN with hardware offload. This includes UDP tunnel segmentation offload and receives side flow steering. GENEVE-SW...

The Evolution of Technology in the Context of Software Development
Article

The Evolution of Technology in the Context of Software Development & Design Process: Take-away from PatternFly Conference

Samir Dash

Last Sunday, I returned home, India, after attending a series of collaborative sessions in Raleigh, NC, with many designers and developers across Red Hat and the open-source community, at the UX Summit and the PatternFly Conference. The whole experience was inspiring, informative and at the same time thought provoking with many takeaways, out of which the most interesting for me was that cumulatively all the inspiring talks from the speakers of the conference were implicitly hinting towards a clue. How...

Red Hat CDK
Article

Running CDK 3.0 on Fedora 25

Brian Brock

Red Hat Container Development Kit (CDK) provides a Container Development Environment (CDE) that allows users to build a virtualized environment for OpenShift. This environment is similar to the user’s production environment and does not need other hardware or a physical cluster. CDK is designed to work on a single user’s desktop computer. The following instructions are to install and use CDK with Fedora 25, but can also be used for earlier versions of Fedora. A significant difference between CDK version...

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Red Hat JBOSS BRMS
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Your first Business Rules application on OpenShift: from Zero to Hero in 30 minutes

Duncan Doyle

In a previous blog post, we explained how to deploy an existing JBoss BRMS/Drools rules project onto an OpenShift DecisionServer. We created a decision/business-rules microservice on OpenShift Container Platform that was implemented by a BRMS application. The polyglot nature of a microservice architecture allowed us to use the best implementation (a rules engine) for this given functionality (business rules execution) in our architecture. The project we used was an existing rules project that was available on GitHub. We did however...

Red Hat Enterprise Linux
Article

Running HPC workloads across multiple architectures with Red Hat Enterprise Linux

Adrian Reber

In this article, I want to provide some background details about our recently developed demonstration video - “ Running Game of Life across multiple architectures with Red Hat Enterprise Linux “. This video shows the Game of Life running in a heterogeneous environment using three 64-bit hardware architectures: aarch64 (ARM v8-A), ppc64le (IBM Power little endian) and x86_64 (Intel Xeon). If you are not familiar with the rules of this cellular automaton, they are worth checking out via the reference...

Speed and the kernel datapath
Article

The need for speed and the kernel datapath - recent improvements in UDP packets processing

Paolo Abeni

Networking hardware is becoming crazily fast, 10Gbs NICs are entry-level for server h/w, 100Gbs cards are increasingly popular and 200Gbs are already surfacing. While the Linux kernel is striving to cope with such speeds with large packets and all kind of aggregation, ISPs are requesting much more demanding workload with NFV and line rate packet processing even for 64 bytes packets. Is everything lost and are we all doomed to rely on some kernel bypass solution? Possibly, but let's first...

DotNET Core process image
Article

Writing a Linux daemon in C#

Takayoshi Tanaka

When you want to run .NET Core process as a daemon on Red Hat Enterprise Linux, you can create a custom systemd unit. Today I'll write about two examples of custom systemd unit for .NET Core. The one is a oneshot type for running a .NET Core console application and the other is a simple type for running an ASP.NET Core Web application. Oneshot type with a console application Building an app You can use dotnet run in systemd with...

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S-RAMP Milestone 2 Screencast

Red Hat Developer Program

S-RAMP is an emerging OASIS standard for a Service Oriented Architecture repository (and accompanying protocol for accessing that repository).

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Reproducible development to live applications with Java and Red Hat CDK

Red Hat Developer Program

Andrew Lee Rubinger, Principle Software Engineer, Red Hat, Lalatendu Mohanty, Sr. Software Engineer, Red Hat share inights in the breakout session from Red Hat Summit 2017. Red Hat Container Development Kit (CDK) provides a ready-to-use development environment for developing microservices on Red Hat OpenShift Container Platform. In this session, we will design a small microservices application using Angular2 served through Eclipse Vert.x for front-end environments and REST over HTTP and Java API for RESTful Web Services (JAX-RS) via WildFly Swarm for back-end environments. We’ll also bootstrap the environment using CDK. This live-coding experience will walk you through setting up a new containerized environment from scratch and using it to develop a functional application in 50 minutes. Learn more: https://www.redhat.com/en/summit/2017/agenda/sessions

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2012 Red Hat Summit: Achieving top network performance

Red Hat Developer Program

In this session, Mark Wagner reviews enhancements in Red Hat Enterprise Linux 6 and show attendees how to take advantage of them in their environments. Mark uses test results from Red Hat's performance lab to highlight the various differences, advantages, and tradeoffs for many technologies, including Kernel-based Virtual Machine (KVM) virtualization technology, 10Gbit Ethernet, Infiniband, FCoE, Packet Flow Control, and RDMA. Mark also presents guidelines and tools for planning and tuning network configurations for low latency and high throughput. He covers the differences between tuning for baremetal, a KVM guest, a Red Hat Storage file system, and NFS. He also touches upon some tricks developers can use when writing network-based applications.

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2012 Red Hat Summit: Part1; Performance Analysis & Tuning of Red Hat Enterprise Linux

Red Hat Developer Program

In this two-hour session, Douglas Shakshober (Shak) and Larry Woodman will explore the system performance analysis and tuning necessary to maximize the performance of systems running Red Hat Enterprise Linux 5 and 6. They will focus on large systems that run the most common applications such as database servers, Internet servers, and various financial applications on a variety of the common hardware platforms.