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It is easy to try a static code analyzer. But it requires skills to introduce it in the development of an old large project. If the approach is incorrect, the analyzer can add work, slow down development, and demotivate the team. Let's briefly discuss how to properly integrate static analysis into the development process and start using it as part of CI/CD.

Greetings to all!

As a matter of fact I haven't found so far any generalized guide on logging and monitoring of metrics from external systems to Kubernetes on the web. Here I want to share with you my own version. First of all it is supposed that you have already got working Prometheus and other services.

As an example I use third-party data for stateful service RDBMS PostgreSQL in a Docker container. In our company we also use the Helm package manager, and you'll find how it works below. You can see same examples in this article below. You can see same examples in this article below. For a complete solution we create a nested chart.

Even the most experienced and highly qualified system administrators often have only a vague idea of what exactly happens during the server startup process. So, let's look at this process in detail.

For any site, it is important to properly configure the HTTP headers. A lot of articles have been written on the subject of headings. Here we have summarized the lessons learned, the RFC documentation. Some of the headings are mandatory, some are obsolete, some can be confusing and contradictory. We did a parsing to automatically check the HTTP headers of the web server.

Correct HTTP headers increase security and trust in the site, including from search engines, can affect the site’s position in Yandex and Google, save server resources, reduce server load, thereby increasing the server response speed, which again affects the ranking of the site in the search, save money on payment powerful hosting, which may not be required for the site when configured correctly.

We are a team of independent developers. We have created a new messenger, the purpose of which is to solve the critical problems of the modern Internet and the modes of communication it provides. We see users become hostages to the services they have grown accustomed to and we see corporations exploiting their users and controlling them. And we don’t like it. We believe the Internet should be different.
In this Manifesto, we disclose our vision of the Internet and describe what we have done to make it better. If you share our ideas — join us. Together we can achieve more than each of us can alone.

There would be no TL;DR in this article, sorry.

Those have been three months that genuinely changed the world. An entire lifeline passed from February, 1, when the coronavirus pandemics just started to spread outside of China and European countries were about to react, to April, 30, when nations were locked down in quarantine measures almost all over the entire world. We want to take a look at the repercussions, cyclic nature of the reaction and, of course, provide DDoS attacks and BGP incidents overview on a timeframe of three months.

In general, there seems to be an objective pattern in almost every country’s shift into the quarantine lockdown.

Today, I am going to explain how to quickly deploy several virtual servers with different operating systems on a single physical server without much effort. This will enable any system administrator to manage the whole corporate IT infrastructure in a centralized manner and save a huge amount of resources.

There’s Gold in Them Thar Hills

Gold rushes can make people crazy. 1848 was enough of an indicator of that. When Sam Brannan announced to the world: ‘Gold! Gold! Gold from the American River!’, half the world’s population (or so it seemed to the tiny California population which lived there at the time) descended on the soon to be the newest state of the union.

San Francisco, before a small hamlet with a few hundred pioneers living there, became a centre of vice, murder and debauchery overnight.



Two hundred years before tulip mania hit Europe, and like in California with its argonauts or 49ers, it impoverished more than it made rich. In the early 2000s, too, the Dot.Com bubble created a speculative tendency in people when irrationality took over all reason.

In the last part we discussed evolution of the interrupt delivery process from the devices in the x86 system (PIC → APIC → MSI), general theory, and all the necessary terminology.

In this practical part we will look at how to roll back to the use of obsolete methods of interrupt delivery in Linux, and in particular we will look at Linux kernel boot options:

• pci=nomsi
• noapic
• nolapic

Also we will look at the order in which the OS looks for interrupt routing tables (ACPI/MPtable/$PIR) and what the impact is from the following boot options:

• pci=noacpi
• acpi=noirq
• acpi=off

You've probably used some combination of these options when one of the devices in your system hasn't worked correctly because of an interrupt problem. We'll go through these options and find out what they do and how they change the kernel '/proc/interrupts' interface output.

Hyperledger Fabric is an open-source blockchain platform from the Linux Foundation. With its help, you can create blockchain applications and control access and permissions for data in the blockchain. The most popular reason to use Hyperledger Fabric is to create a private blockchain network or set restrictions on what transactions each side can see.

The documentation of Hyperledger Fabric describes the creation of a blockchain network on one machine using Docker, where each member of the network is a separate container. But the process of setting up a network on several physical or virtual machines is not well described. Therefore, we decided to discuss this in the article.

Our blockchain application is a service for storing the medical data of school and preschool children. The data must remain unchanged. It will be presented in the form of information on vaccination and on the patient's agreement with a particular doctor. The members of the network include Parents (an organization that represents the interests of parents), Hospital (a hospital which represents pediatricians with whom parents can enter into an agreement to care for their children) and Kindergarten (a kindergarten that can request health and vaccinations reports of a child from the hospital).

Fast SSDs are getting cheaper every year, but they are still smaller and more expensive than traditional HDD drives. But HDDs have much higher latency and are easily saturated. However, we want to achieve low latency for the storage system, and a high capacity too. There’s a well-known practice of optimizing performance for big and slow devices — caching. As most of the data on a disk is not accessed most of the time but some percentage of it is accessed frequently, we can achieve a higher quality of service by using a small cache.

Server hardware and operating systems have a lot of caches working on different levels. Linux has a page cache for block devices, a dirent cache and an inode cache on the filesystem layer. Disks have their own cache inside. CPUs have caches. So, why not add one more persistent cache layer for a slow disk?

To exclude some folder from the defender list can be used cmdlet Set-MpPreference
Manly, now you can stop reading, go to the PowerShell and update excludes:)
But if you are want to see how to perform this in more detail — welcome under the habrcut.

UPD: Added a script to add selected folder to excluded Defender locations (at the end of the post)

There was a custom configuration management solution.

I would like to share the story about a project. The project used to use a custom configuration management solution. Migration lasted 18 months. You can ask me 'Why?'. There are some answers below about changing processes, agreements and workflows.

It is the translation of my speech at DevOps-40 2020-03-18:

After the second commit, each code becomes legacy. It happens because the original ideas do not meet actual requirements for the system. It is not bad or good thing. It is the nature of infrastructure & agreements between people. Refactoring should align requirements & actual state. Let me call it Infrastructure as Code refactoring.

The basics of porting

Originally, Buildroot offers a limited number of packages. It makes sense — there is everything you need, but any other packages can be added.

To add a package, create 2 description files, an optional checksum file, and add a link to the package in the general package list. There are hooks at different stages of the build. At the same time, Buildroot can recognize the needed type of packages:

Scientists said they were able to return the state of a quantum computer a fraction of a second into the past, according to a university press release. The researchers, who are from the Moscow Institute of Physics and Technology, along with colleagues from the U.S. and Switzerland, also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study came out recently in Scientific Reports.

“This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time: from the past to the future,” commented the study’s lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.

While the researchers don’t expect you to take a trip back to the high school prom just yet, they added that the time reversal algorithm could prove useful for making quantum computers more precise.

“Our algorithm could be updated and used to test programs written for quantum computers and eliminate noise and errors,” Lebedev explained.

The researchers said that the work builds on some earlier work that recently garnered headlines.

“We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell’s demon,” Lesovik said. “The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time.”

Due to a rapid increase in remote work, we have decided to offer video conferencing. Like most of our services, it is free of charge. It is built on a reliable open-source solution, it is mostly based on WebRTC, which allows communicating in the browser by just clicking on a link. Below we’ll tell you more about its features and some of the problems we’ve run into.

The case: You fire up a professionally prepared Linux image at a cloud platform provider (Amazon, DO, Google, Azure, etc.) and it will run a kind of production level service moderately exposed to hacking attacks (non-targeted, non-advanced threats).

What would be the standard quick security related tuning to configure before you install the meat?

release: 2005, Ubuntu + CentOS (supposed to work with Amazon Linux, Fedora, Debian, RHEL as well)

We continue telling you about our cooperation with Innopolis University guys to develop Active Restore technology. It will allow users to start working as soon as possible after a failure. Today, we will talk about Native Windows applications, including details on their development and launch. Under the cut, you will find some information about our project, and a hands-on guide on developing native apps.

In just a few years, quantum computing and quantum information theory has gone from a fringe subject offered in small classes at odd hours in the corner of the physics building annex to a full complement of classes in well-funded programs being held at quantum centers and institutes at leading universities.

The question now for many would-be quantum computer students is not, “Are there universities that even offer classes in quantum computing,” but, rather, “Which universities are leaders at quantum computing research.”

We’ll look at some of the best right now:

The Institute for Quantum Computing — University of Waterloo

The University of Waterloo can proudly declare that, while many universities avoided offering quantum computing classes like cat adoption agencies avoided adoption applications from the Schrodinger family, this Canadian university went all in.

And it paid off.