There are two supported protocols in Red Hat Enterprise Linux for synchronization of computer clocks over a network. The older and more well-known protocol is the Network Time Protocol (NTP). In its fourth version, NTP is defined by IETF in RFC 5905. The newer protocol is the Precision Time Protocol (PTP), which is defined in the IEEE 1588-2008 standard.
The reference implementation of NTP is provided in the ntp package. Starting with Red Hat Enterprise Linux 7.0 (and now in Red Hat Enterprise Linux 6.8) a more versatile NTP implementation is also provided via the chrony package, which can usually synchronize the clock with better accuracy and has other advantages over the reference implementation. PTP is implemented in the linuxptp package.
With two different protocols designed for synchronization of clocks, there is an obvious question as to which one is
Continue reading “Combining PTP with NTP to Get the Best of Both Worlds”
Paradoxically, there has never been a better or more confusing time to discuss which platform is most appropriate for a given workload. As we seek to solve problems around automation, continuous integration / continuous delivery, ease of upgrades, operational complexity, uptime, compliance, and many other complex issues – it quickly becomes clear that there are more than a few viable options. Making matters worse – there is too much focus on the “how” (to adopt a given platform) and not enough focus onthe “why”. To this end, I’d like to address more of the “why” in an attempt to better influence the “how”.
Continue reading “Choosing a Platform Based on Workload Characteristics”
Hello again! In this post I will be sharing some ideas about what you can do to solve a complex identity management challenge.
As the adoption of Identity Management (IdM) grows and especially in the case of heterogeneous environments where some systems are running Linux and user accounts are in the Active Directory (AD) – the question of renaming hosts becomes more and more relevant. Here is a set of requirements that we often hear from customers
Continue reading “I Really Can’t Rename My Hosts!”
In our first post defending the pet container, we looked at the challenge of complexity facing modern software stacks and one way that containers address this challenge through aggregation. In essence, the Docker “wrapper” consolidates the next level of the stack, much like RPM did at the component level, but aggregation is just the beginning of what the project provides.
If we take a step back and look at the Docker project in context, there are four aspects that contribute to its exceptional popularity:
- it simplifies the way users interact with the kernel, for features we have come to call Linux containers;
- it’s a tool and format for aggregate packaging of software stacks to be deployed into containers;
- it is a model for layering generations of changes on top of each other in a single inheritance model;
- it adds a transport for these aggregate packages.
Continue reading “In Defense of the Pet Container, Part 2: Wrappers, Aggregates and Models… Oh My!”
It’s been a busy few weeks for us on the Atomic Host team, and we’re excited to announce the release of Red Hat Enterprise Linux Atomic Host 7.2.5! This is a big one too. For those not familiar with our release cadence, we release a new version of Atomic Host every six weeks. This enables us to balance the reliability of Red Hat Enterprise Linux with exciting new features and capabilities from our Project Atomic upstream community in a production ready, supportable manor.
Now, let’s walk through some key new features in Atomic Host:
Continue reading “What’s New in Red Hat Enterprise Linux Atomic Host 7.2.5”
In November 2015, I blogged about the announcement to bring .NET to RHEL from the .NET Core upstream project to enterprise customers and developers, both as an RPM and as a Linux container. That was quite a moment for the industry and, quite frankly, for me as well, having participated in the discussions that led to the significant announcement with Microsoft. Since then, we have been in tight collaboration to make sure this day would actually arrive. Despite the usual challenges with a relatively new open source project, the project was
Continue reading “.NET Core on Red Hat Enterprise Linux”
As a Solutions Architect, I enjoy creating and adding custom configurations to my Red Hat Enterprise Virtualization(RHEV) environment using a feature called hooks. A hook is a custom script that executes at a certain point during a RHEV event. You can attach scripts to several events. To see the full list of RHEV hooks, do a directory listing of “/usr/libexec/vdsm/hooks” on a RHEV hypervisor and you will see the below list.
Continue reading “Using Hooks in Red Hat Enterprise Virtualization”
If you’re heading to DockerCon 16 next week in Seattle, connect with us to see why Fortune 500 organizations trust Red Hat for enterprise deployments. Red Hat subject matter experts will be onsite to walk you through real-world use cases for securely developing, deploying and managing container-based applications.
Attend the State of Container Security Session
Join two of Red Hat’s Docker contributors discussing the state of container security today. Senior Software Engineer Mrunal Patel and Thomas Cameron, Global Evangelist of Emerging Technology are presenting on how you can secure your containerized microservices without slowing down development.
Continue reading “Red Hat at DockerCon 16 in Seattle”
As a Solutions Architect with over 25 years of experience, I have participated in a large number of requests for information/proposals (RFI/RFP) and other technology evaluations. Often these evaluations include extended long and detailed lists of requirements and features. Due to my deep industry experience, I can easily recognize some patterns in how these lists are created. These lists are either based on the market leaders’ datasheets or information from 3rd party research documents that heavily draw from the market leaders’ datasheets. We can easily identify a circular loop of information which can lead to a few problems:
Continue reading “Don’t Be Fooled by the Feature List”
It’s been just over three years since Solomon Hykes presented the world with the (so far) most creative way to use the tar command: the Docker project. Not only does the project combine existing container-technologies and make them easier to use, but its well-timed introduction drove an unprecedented rate of adoption for new technology.
Did people run containers before the Docker project? Yes, but it was harder to do so. The broader community was favoring LXC, and Red Hat was working on a libvirt-based model for Red Hat Enterprise Linux. With OpenShift 2, Red Hat had already been running containers in production for several years – both in an online PaaS as well as on-premise for enterprise customers. The model pre-Docker however was fundamentally different from what we are seeing today: rather than enabling completely independent runtimes inside the containers, the approach in
Continue reading “In Defense of the Pet Container, Part 1: Prelude – The Only Constant is Complexity”