Administration Section
Note: This is a translation of a public postmortem from the engineering blog of Preply. It describes an issue with conntrack in a Kubernetes cluster that led to partial downtime of certain production services. This article may be useful for those who want to learn a bit more about postmortems or prevent potential DNS issues in the future. This is not DNS It cannot be […]
Preface Just a week ago, I wrote a paper on the topic indicated in the title and found that, shall we say, there isn't much enlightening information available online. Mostly dry facts and setup instructions. Therefore, I decided to tweak the text a bit and post it as an article. What is FTP FTP (File Transfer Protocol) ā […]
The National Environmental Satellite, Data, and Information Service (NESDIS) has reduced its operating costs for managing Red Hat Enterprise Linux (RHEL) by 35% by transitioning from Puppet Enterprise to Ansible Tower. In this "how we did it" video, Systems Engineer Michael Rau explains the rationale behind this migration, shares useful tips, and discusses the experiences gained from the transition from […]
Good day everyone. I will start with a backstory about what prompted me to conduct this research, but first, I must warn you: all practical actions were performed with the consent of management structures. Any attempt to use this material for unauthorized access to restricted areas is a criminal offense. It all began when I was cleaning my desk, I […]
Chapters 1, 2, 3 Getting Started 3.1 Overview 3.2 Prerequisites 3.2.1 Downloading the ns-3 Release as a Source Archive 3.3 Downloading ns-3 Using Git 3.3.1 Downloading ns-3 with Bake 3.4 Building ns-3 3.4.1 Building with build.py 3.4.2 Building with Bake 3.4.3 Building with Waf 3.5 Testing ns-3 3.6 Running the Script 3.6.1 Arguments […]
Chapters 1, 2, Chapter 3 4 Concept Overview 4.1 Key Abstractions 4.1.1 Node 4.1.2 Application 4.1.3 Channel 4.1.4 Net Device 4.1.5 Topological Helpers 4.2 The First ns-3 Script 4.2.1 Boilerplate Code 4.2.2 Plug-in Modules 4.2.3 ns3 Namespace 4.2.4 Logging 4.2.5 Main Function 4.2.6 Using Topological Helpers 4.2.7 Using Application 4.2.8 Simulator […]
Chapters 1, 2, Chapter 3, Chapter 4 5 Configuration 5.1 Using the Logging Module 5.1.1 Logging Overview 5.1.2 Enabling Logging 5.1.3 Adding Logging to Your Code 5.2 Using Command Line Arguments 5.2.1 Overriding Default Attribute Values 5.2.2 Capturing Your Own Commands 5.3 Using the Tracing System 5.3.1 ASCII Tracing Parsing ASCII Traces 5.3.2 PCAP Tracing Chapter 5 […]
On November 27, 1923, American radio amateurs John Reinartz (John L. Reinartz, 1QP) and Fred Schnell (Fred H. Schnell, 1MO) conducted two-way transatlantic radio communication with French amateur operator LĆ©on Deloy (LĆ©on Deloy, F8AB) on a wavelength of about 100 m. This event had a significant impact on the development of the global amateur radio movement and shortwave communication. One of […]
Let me explain the title of the article right away. Initially, it was planned to provide good, reliable advice on speeding up the use of reflection with a simple but realistic example, but during benchmarking, it turned out that reflection does not work as slowly as I thought, while LINQ works slower than I could have imagined. In the end, I also made an error in the measurementsā¦ Details of this […]
Recently, David O'Brien launched his own company Xirus (https://xirus.com.au), focusing on Microsoft Azure Stack cloud products. They are designed for the consistent creation and deployment of hybrid applications in data centers, edge locations, remote offices, and the cloud. David trains individuals and companies on everything related to Microsoft Azure and Azure DevOps (formerly VSTS) and up to […]
This is the transcript of the presentation at DevopsConf 2019-10-01 and SPbLUG 2019-09-25. It tells the story of a project that used a custom configuration management system and why the migration to Ansible took 18 months. Day No -XXX: Before the beginning Initially, the infrastructure consisted of several standalone hosts managed by Hyper-V. Creating a virtual machine required numerous steps: putting the disks in the right […]
Today, for most companies and organizations, data is one of their strategic assets. With the expansion of analytics capabilities, the value of the data collected and accumulated by companies is continually increasing. There is often talk of the explosive, exponential growth of the volumes of corporate data generated. It is noted that 90% of all data has been created in the last two years. The growth of data volumes is accompanied by an increase in their […]