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Hello world! Or Habr in English, v1.0

Reading time4 min
Views30K
This is the first post in our blog in 2019. And this is important for all of us: we are finally launching the English version of Habr! Actually it was ready in the middle of December, but — you know — releasing a new feature right before Christmas is like deploying on Friday afternoon. So we decided to do it in the beginning of 2019.


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Total votes 180: ↑178 and ↓2+176
Comments247

A small notebook for a system administrator

Reading time21 min
Views161K
I am a system administrator, and I need a small, lightweight notebook for every day carrying. Of course, not just to carry it, but for use it to work.

I already have a ThinkPad x200, but it’s heavier than I would like. And among the lightweight notebooks, I did not find anything suitable. All of them imitate the MacBook Air: thin, shiny, glamorous, and they all critically lack ports. Such notebook is suitable for posting photos on Instagram, but not for work. At least not for mine.

After not finding anything suitable, I thought about how a notebook would turn out if it were developed not with design, but the needs of real users in mind. System administrators, for example. Or people serving telecommunications equipment in hard-to-reach places — on roofs, masts, in the woods, literally in the middle of nowhere.

The results of my thoughts are presented in this article.

Figure to attract attention
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Total votes 91: ↑88 and ↓3+85
Comments57

Nginx's office is being searched due to Rambler Group's lawsuit. The complaintant press service confirmed the suit

Reading time5 min
Views17K
According to one of the employees Nginx's Moscow office is being searched due to the criminal case brought by Rambler Group (the official response of the company's press office to this issue and confirmation of claims against Nginx is below). The photo of the search warrant is provided as the evidence of the criminal case initiated on December 4, 2019 under Article 146 of the Criminal Code of the Russian Federation 'Violation of Author's and Neighboring Rights'.

Nginx search warrant


It is assumed the complaintant is Rambler, and the defendant is still an 'unidentified group of persons', and in the long run — the founder of Nginx, Igor Sysoyev.

The point of the claim: Igor started working on Nginx as an employee of Rambler and only after the tool became popular he founded a separate company and attracted investments.

It is not clear why Rambler revised its 'property' only 15 years later.
Total votes 78: ↑78 and ↓0+78
Comments4

Flightradar24 — how does it work?

Reading time4 min
Views122K
I’m going to hazard a guess and say that everyone whose friends or family have ever flown on a plane, have used Flightradar24 — a free and convenient service for tracking flights in real time.



But, if my friends are any indication, very few people know that the service is community-driven and is supported by a group of enthusiasts gathering and sending data. Even fewer people know that anyone can join the project — including you.

Let’s see how Flightradar and similar other services works.
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Total votes 80: ↑79 and ↓1+78
Comments12

Google Interviewing Process for Software Developer Role in 2020

Reading time6 min
Views83K

Hello! I just finished interviewing with Google and wanted to quickly catch you up on some interesting and frustrating steps of the process so that you can understand what to expect from Google interviews and the steps involved. I will also share some tips on how to prepare for the interview and mistakes to avoid.

If you’re looking for a success story, this is the wrong post for you. I actually failed the interviewing process, but the whole experience was pretty interesting for me and leads me on to another stage of my career. I will share more details on this at the end of the post. All names and identifying details have been changed to protect the privacy of Google employees.
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Total votes 71: ↑70 and ↓1+69
Comments9

How Protonmail is getting censored by FSB in Russia

Reading time10 min
Views8.4K

A completely routine tech support ticket has uncovered unexpected bans of IP addresses of Protonmail — a very useful service for people valuing their Internet freedoms — in several regions of Russia. I seriously didn’t want to sensationalize the headline, but the story is so strange and inexplicable I couldn’t resist.


TL;DR


Disclaimer: the situation is still developing. There might not be anything malicious, but most likely there is. I will update the post once new information comes through.


MTS and Rostelecom — two of the biggest Russian ISPs — started to block traffic to SMTP servers of the encrypted email service Protonmail according to an FSB request, with no regard for the official government registry of restricted websites. It seems like it’s been happening for a while, but no one paid special attention to it. Until now.


All involved parties have received relevant requests for information which they’re obligated to reply.


UPD: MTS has provided a scan of the FSB letter, which is the basis for restricting the access. Justification: the ongoing Universiade in Krasnoyarsk and “phone terrorism”. It’s supposed to prevent ProtonMail emails from going to emergency addresses of security services and schools.


UPD: Protonmail was surprised by “these strange Russians” and their methods for battling fraud abuse, as well as suggested a more effective way to do it — via abuse mailbox.


UPD: FSB’s justification doesn’t appear to be true: the bans broke ProtonMail’s incoming mail, rather than outgoing.


UPD: Protonmail shrugged and changed the IP addresses of their MXs taking them out of the blocking after that particular FSB letter. What will happen next is open ended question.


UPD: Apparently, such letter was not the only one and there is still a set of IP addresses of VOIP-services which are blocked without appropriate records in the official registry of restricted websites.

Total votes 66: ↑64 and ↓2+62
Comments4

PVS-Studio 7.00

Reading time6 min
Views3.9K
PVS-Studio C#\Java\C++Today is an important day — after 28 releases of the sixth version we present our PVS-Studio 7.00, in which the key innovation is the support of the Java language. However, during 2018 we have acquired many other important changes related to C++, C#, infrastructure and support of coding standards. Therefore, we bring to your attention a note that sums up the major changes that have happened in PVS-Studio for the last time.
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Total votes 52: ↑51 and ↓1+50
Comments3

How we made landmark recognition in Cloud Mail.ru, and why

Reading time11 min
Views2.4K


With the advent of mobile phones with high-quality cameras, we started making more and more pictures and videos of bright and memorable moments in our lives. Many of us have photo archives that extend back over decades and comprise thousands of pictures which makes them increasingly difficult to navigate through. Just remember how long it took to find a picture of interest just a few years ago.

One of Mail.ru Cloud’s objectives is to provide the handiest means for accessing and searching your own photo and video archives. For this purpose, we at Mail.ru Computer Vision Team have created and implemented systems for smart image processing: search by object, by scene, by face, etc. Another spectacular technology is landmark recognition. Today, I am going to tell you how we made this a reality using Deep Learning.
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Total votes 45: ↑44 and ↓1+43
Comments0

A bot for Starcraft in Rust, C or any other language

Reading time12 min
Views43K

StarCraft: Brood War. This game means so much to me! And to many of you, I guess. So much, that I wonder if I should even give a link to its page on Wikipedia or not.


Once Halt sent me PM and offered to learn Rust. Like any ordinary people, we decided to start with hello world writing a dynamic library for Windows that could be loaded into StarCraft's address space and manage units.


The following article will describe the process of finding solutions and using technologies and techniques that will allow you to learn new things about Rust and its ecosystem. You may also be inspired to implement a bot using your favorite language, whether it be C, C++, Ruby, Python, etc.

Ready to roll out!
Total votes 45: ↑44 and ↓1+43
Comments3

Making Git for Windows work in ReactOS

Reading time10 min
Views4.7K

Good day to you! image


My name is Stanislav and I like to write code. This is my first english article on Habr which I made due to several reasons:



This article is an english version of my very first article on russian.


Let me introduce the main figures in this story who actually fixed the bug preventing Git from running in ReactOS — the French developer Hermès Bélusca-Maïto (or just Hermes with hbelusca nickname) and of course me (with x86corez nickname).


The story begins with the following messages from the ReactOS Development IRC channel:


Jun 03 18:52:56 <hbelusca> Anybody want to work on some small problem? If so, can someone figure out why this problem https://jira.reactos.org/browse/CORE-12931 happens on ReactOS? :D
Jun 03 18:53:13 <hbelusca> That would help having a good ROS self-hosting system with git support.
Jun 03 18:53:34 <hbelusca> (the git assertion part only).
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Total votes 44: ↑43 and ↓1+42
Comments1

Stack-based calculator on the Cyclone IV FPGA board

Reading time12 min
Views9.7K

Introduction


As first-year students of Innopolis University, we had an opportunity to make our own project in computer architecture. University suggested us several projects and we have chosen to make a stack-based calculator with reverse polish notation. One of the requirements for the project is to use FPGA board provided by the university.



As our board, we have chosen Cyclon IV. Therefore, we had to write code on hardware description language. In the course we have studied Verilog, so we have chosen it. Also, the university has additional modules for FPGA, such as numpad, thus we decided to use it in our project.

In this article, we want to share our knowledge about FPGA and Verilog, also provide you with a tutorial to repeat our project.
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Total votes 75: ↑58 and ↓17+41
Comments27

How to Make Emails and Not Mess Up: Practical Tips

Reading time23 min
Views3.1K


A developer, who first encountered generating emails, has almost no chance to write an application, that will do it correctly. Around 40% of emails, generated by corporate applications, are violating some form of standard, and due to this, there are problems with delivery and display. There are reasons for this: emails are technically more difficult than the web, and operating emails is regulated by a few hundred standards, as well as an uncountable number of generally accepted (and not as much) practices, whereas the email clients are more varied and unpredictable than browsers. Testing may significantly improve the situation, but materials that are dedicated to testing the email system, are practically non-existent.

Mail.ru regularly interacts with its users by email. In our projects, all the components responsible for generating emails and even individual mailings, are subject to mandatory testing. In this article, we will share our experience (learning from our mistakes).
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Total votes 40: ↑40 and ↓0+40
Comments2

Accelerating PHP connectors for Tarantool using Async, Swoole, and Parallel

Reading time6 min
Views2.2K


In the PHP ecosystem, there are currently two connectors for the Tarantool server: the official PECL extension tarantool/tarantool-php written in C, and tarantool-php/client written in PHP. I am the author of the latter one.

In this article I would like to share the results of performance testing of both these libraries and show how you can achieve 3x-5x performance improvement (on synthetic tests!) with minimal changes in code.
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Total votes 39: ↑39 and ↓0+39
Comments0

The best is the enemy of the good

Reading time11 min
Views1.2K

Picture 6

This article is the story how we once decided to improve our internal SelfTester tool that we apply to test the quality of the PVS-Studio analyzer. The improvement was simple and seemed to be useful, but got us into some troubles. Later it turned out that we'd better gave up the idea.
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Total votes 43: ↑41 and ↓2+39
Comments0

Counting Bugs in Windows Calculator

Reading time11 min
Views42K

A few days ago, Microsoft made the source code of their Windows Calculator publicly available. Calculator is an application that has traditionally shipped with every Windows version. A number of Microsoft projects went open-source over the recent years, but this time the news was covered even by non-IT media on the very first day. Well, it's a popular yet tiny program in C++. Despite its size, we still managed to find a number of suspicious fragments in its code using the PVS-Studio static analyzer.
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Total votes 44: ↑41 and ↓3+38
Comments2

System in Package, or What's Under Chip Package Cover?

Reading time7 min
Views5.1K
Transistor feature size is decreasing despite constant rumors about the death of Moore’s law and the fact that industry is really close to physical limits of miniaturisation (or even went through them with some clever technology tricks). Moore’s law, however, created user’s appetite for innovation, which is hard to handle for the industry. That’s why modern microelectronic products aren’t just feature size scaled, but also employ a number of other features, often even more complicated than chip scaling.


Disclaimer: This article is a slightly updated translation of my own piece published on this very site here. If you're Russian-speaking, you may want to check the original. If you're English-speaking, it's worth noting that English is not my native language, so I'll be very grateful for the feedback if you find something weird in the text.
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Total votes 38: ↑38 and ↓0+38
Comments0

Tarantool Data Grid: Architecture and Features

Reading time6 min
Views2.1K


In 2017, we won the competition for the development of the transaction core for Alfa-Bank's investment business and started working at once. (Vladimir Drynkin, Development Team Lead for Alfa-Bank's Investment Business Transaction Core, spoke about the investment business core at HighLoad++ 2018.) This system was supposed to aggregate transaction data in different formats from various sources, unify the data, save it, and provide access to it.

In the process of development, the system evolved and extended its functions. At some point, we realized that we created something much more than just application software designed for a well-defined scope of tasks: we created a system for building distributed applications with persistent storage. Our experience served as a basis for the new product, Tarantool Data Grid (TDG).

I want to talk about TDG architecture and the solutions that we worked out during the development. I will introduce the basic functions and show how our product could become the basis for building turnkey solutions.
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Total votes 39: ↑38 and ↓1+37
Comments0

Contextual Emotion Detection in Textual Conversations Using Neural Networks

Reading time10 min
Views3.7K

Nowadays, talking to conversational agents is becoming a daily routine, and it is crucial for dialogue systems to generate responses as human-like as possible. As one of the main aspects, primary attention should be given to providing emotionally aware responses to users. In this article, we are going to describe the recurrent neural network architecture for emotion detection in textual conversations, that participated in SemEval-2019 Task 3 “EmoContext”, that is, an annual workshop on semantic evaluation. The task objective is to classify emotion (i.e. happy, sad, angry, and others) in a 3-turn conversational data set.
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Total votes 37: ↑37 and ↓0+37
Comments0

2019 National Internet Segments Reliability Research & Report

Reading time9 min
Views3.5K


This report explains how the outage of a single AS can affect the connectivity of the impacted region with the rest of the world, especially when it is the dominant ISP on the market. Internet connectivity at the network level is driven by interaction between autonomous systems (AS’s). As the number of alternate routes between AS’s increases, so goes the fault-resistance and stability of the internet across the network. Although some paths inevitably become more important than others, establishing as many alternate routes as possible is the only viable way to ensure an adequately robust system.

The global connectivity of any AS, regardless of whether it is a minor provider or an international giant, depends on the quantity and quality of its paths to Tier-1 ISPs. Usually, Tier-1 implies an international company offering global IP transit service over connections to other Tier-1 providers. But there is no guarantee that such connectivity will be maintained. Only the market can motivate them to peer with other Tier-1’s to deliver the highest quality service. Is that enough? We explore this question in the IPv6 section below. For many ISPs at all levels, losing connection to just one Tier-1 peer would likely render them unreachable in some parts of the world.

Measuring Internet Reliability


Let’s examine a case where an AS experiences significant network degradation. We want to answer the following question: “How many AS’s in the region would lose connectivity with Tier-1 operators and their global availability along with it?”
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Total votes 37: ↑36 and ↓1+35
Comments2

Tarantool Kubernetes Operator

Reading time10 min
Views1.8K


Kubernetes has already become a de-facto standard for running stateless applications, mainly because it can reduce time-to-market for new features. Launching stateful applications, such as databases or stateful microservices, is still a complex task, but companies have to meet the competition and maintain a high delivery rate. So they create a demand for such solutions.

We want to introduce our solution for launching stateful Tarantool Cartridge clusters: Tarantool Kubernetes Operator, more under the cut.
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Total votes 34: ↑34 and ↓0+34
Comments0
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