Development

We have already presented Tarantool Cartridge that allows you to develop and pack distributed applications. Now let's learn how to deploy and control these applications. No panic, it's all under control! We have brought together all the best practices of working with Tarantool Cartridge and wrote an Ansible role, which will deploy the package to servers, start and join instances into replica sets, configure authorization, bootstrap vshard, enable automatic failover and patch cluster configuration.

Interesting, huh? Dive in, check details under the cut.

The AI Cup community and Mail.ru Group in collaboration with Codeforces.com invite you to the real battle! Get ready for the sleepless nights and calloused hands — take part in Russian AI Cup, which is one of the most challenging and vivid artificial intelligence programming competitions in the world. Believe us, managers of this madness did their best to create the game you'd want to play.

To become part of the competition, you need Internet access, computer, creativity, and enthusiasm for being a part of this extraordinary Cup. By the way, you might need some coffee. Welcome!

During the summer of 2019, Huawei gave a series of presentations announcing the Ark Compiler technology. The company claims that this open-source project will help developers make the Android system and third-party software much more fluent and responsive. By tradition, every new promising open-source project goes through PVS-Studio for us to evaluate the quality of its code.

Introduction

The Ark Compiler was first announced by Huawei at the launch of the new smartphone models P30 and P30 Pro. It is claimed that the Ark Compiler will improve the fluency of the Android system by 24% and response speed by 44%. Third-party Android applications will also gain a 60% speed-up after recompilation with the Ark Compiler. The open-source version of the project is called OpenArkCompiler; its source code is available on Gitee, a Chinese fork of GitHub.

Nowadays everyone knows about cloud services. Many companies have cracked this market segment and created their own cloud services of various purposes. Recently our team has also been interested in these services in terms of integrating the PVS-Studio code analyzer into them. Chances are, our regular readers have already guessed what type of project we will check this time. The choice fell on the code of Huawei cloud services.

This article continues the series of publications on usage of PVS-Studio in cloud systems. This time we'll look at the way the analyzer works along with GitLab CI, which is a product made by GitLab Inc. Static analyzer integration in a CI system allows detecting bugs right after the project build and is a highly effective way to reduce the cost of finding bugs.

Hi! Though the 2019 conference season is not over yet, we'd like to talk about the bug-finding challenges we offered to visitors at our booth during the past conferences. Starting with the fall of 2019, we've been bringing a new set of challenges, so we can now reveal the solutions to the previous tasks of 2018 and the first half of 2019 – after all, many of them came from previously posted articles, and we had a link or QR code with information about the respective articles printed on our challenge leaflets.

It is a new selection of tips and tricks about Python and programming from my Telegram-channel @pythonetc.

← Previous publications


If you want to iterate over several iterables at once, you can use the zip function (it has nothing to do with ZIP file format):

An online chatbot is a recent trend on the market. But how to interact with the clients that are offline? A significant percentage of people prefer to interact over the phone. And the business needs either a large staff of operators or a voice communication automating solution. We are offering a solution to reduce workload and costs (and will barely affect your developers’ busyness).

This is a guest post from the Orleans team. Orleans is a cross-platform framework for building distributed applications with .NET. For more information, see https://github.com/dotnet/orleans.

We are excited to announce the Orleans 3.0 release. A great number of improvements and fixes went in, as well as several new features, since Orleans 2.0. These changes were driven by the experience of many people running Orleans-based applications in production in a wide range of scenarios and environments, and by the ingenuity and passion of the global Orleans community that always strives to make the codebase better, faster, and more flexible. A BIG Thank You to all who contributed to this release in various ways!

A couple of reader alerts:

In order to (somewhat) simplify the description process and tighten the volume of the article we are going to write, it is essential to make a significant remark and state the primary constraint right away — everything we are going to tell you today on the practical side of the problematics is viable only in terms of TLS 1.3. Meaning that while your ECDSA certificate would still work in TLS 1.2 if you wish it worked, providing backwards compatibility, the description of the actual handshake process, cipher suits and client-server benchmarks covers TLS 1.3 only. Of course, this does not relate to the mathematical description of algorithms behind modern encryption systems.

This article was written by neither a mathematician nor an engineer — although those helped to find a way around scary math and reviewed this article. Many thanks to Qrator Labs employees.

(Elliptic Curve) Diffie-Hellman (Ephemeral)

The Diffie–Hellman legacy in the 21 century

Of course, this has started with neither Diffie nor Hellman. But to provide a correct timeline, we need to point out main dates and events.

There were several major personas in the development of modern cryptography. Most notably, Alan Turing and Claud Shannon both laid an incredible amount of work over the field of theory of computation and information theory as well as general cryptanalysis, and both Diffie and Hellman, are officially credited for coming up with the idea of public-key (or so-called asymmetric) cryptography (although it is known that in the UK there were made serious advances in cryptography that stayed under secrecy for a very long time), making those two gentlemen pioneers.

In what exactly?

Anyone who programs microcontrollers probably knows about FreeRTOS, or at least heard of this operating system. Amazon developers decided to enhance the abilities of this operating system to work with AWS Internet of Things services. This is how Amazon FreeRTOS appeared. We, developers of the PVS-Studio static code analyzer, were asked by mail and in comments to check these projects. Well, now get what you asked for. Keep reading to find out what came out of it.

Chapter 2.
(the link to Chapter 1)

The Art of Designing Road Networks

Transport problems of a city through the eyes of a Computer Scientist

If I were recommended an article with the title “The Art of Designing Road Networks,” I would immediately ask how many road networks were built with the participation of its author. I must admit, my professional activity was far from road construction and was recently associated with the design of microprocessors where I, among other responsibilities, was engaged in the resource consumption of data switching. At that time my table stood just opposite the panoramic window which opened up a beautiful view of the long section of the Volgograd Highway and part of the Third Transport Ring with their endless traffic jams from morning to evening, from horizon to horizon. One day, I had a sudden shock of recognition: “The complexities of the data switching process that I struggle with on a chip may be similar to the difficulties the cars face as they flow through the labyrinth of road network”.
Probably, this view from the outside and the application of methods that were not traditional for the area in question gave me a chance to understand the cause of traffic jams and make recommendations on how to overcome the problem in practice.

Most likely you've already heard about the famous exploit checkm8, which uses an unfixable vulnerability in the BootROM of most iDevices, including iPhone X. In this article, we'll provide a technical analysis of this exploit and figure out what causes the vulnerability.

While Stockholm was holding the 118th Nobel Week, I was sitting in our office, where we develop the PVS-Studio static analyzer, working on an analysis review of the ROOT project, a big-data processing framework used in scientific research. This code wouldn't win a prize, of course, but the authors can definitely count on a detailed review of the most interesting defects plus a free license to thoroughly check the project on their own.

Introduction

ROOT is a modular scientific software toolkit. It provides all the functionalities needed to deal with big data processing, statistical analysis, visualisation and storage. It is mainly written in C++. ROOT was born at CERN, at the heart of the research on high-energy physics. Every day, thousands of physicists use ROOT applications to analyze their data or to perform simulations.

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.

This article reviews the results of a second check of the Orchard project with the PVS-Studio static analyzer. Orchard is an open-source content manager system delivered as part of the ASP.NET Open Source Gallery under the non-profit Outercurve Foundation. Today's check is especially interesting because both the project and the analyzer have come a long way since the first check, and this time we'll be looking at new diagnostic messages and some nice bugs.

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.

Open Graph protocol is a web standard originally developed by Facebook that turns any webpage into a graph object with title, description, image and so on. Even though there is no direct correlation between OG meta tags and improved SEO rankings, it still drives more traffic to your webpage by making it more “attractive” in social networks (Facebook, Twitter, Linkedin, etc).

An example of a link shared in Twitter that has «og:image» and «og:title».

Adding OG (and not only) meta tags into your React app

Without further due let’s jump into newly created React app with create-react-app and OG meta tags to /public/index.html. It should look like something like this:

<!DOCTYPE html>
<html>
   <head>
      <meta charSet="utf-8"/>
      <meta http-equiv="x-ua-compatible" content="ie=edge"/>
      <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"/>
      <link rel="alternate" type="application/rss+xml" href="/rss.xml"/>
      <title>Awesome App</title>
      <meta property="og:title" content="Awesome app - the best app ever" />
      <meta property="og:type" content="website" />
      <meta property="og:image" content="https://picsum.photos/id/52/1200/600" />
      <meta property="og:description" content="Describe stuff here." />
      <meta property="og:url" content="yourawesomeapp.com" />
   </head>
   <body>
      <noscript>This app works best with JavaScript enabled.</noscript>
      <div id="root"></div>
   </body>
</html>

On October 7, 2019, Apple released a new version of its Mac operating system, macOS Catalina. Version 10.15 contains many changes and improvements. One of the significant is the complete phasing out of 32-bit applications. As a developer of such macOS apps, what can you do? That's right, port the app to the 64-bit platform. Will the application work properly from the first attempt? Perhaps, it's possible. Depends on the complexity and amount of the code. But most likely, developers will face a lot of non-obvious errors, which can previously detected using PVS-Studio.

Vue.js is a JavaScript library for building web interfaces. Combining with some other tools It also becomes a “framework”. Now, from our last blog, you already know that Vue.js is one of the top JavaScript frameworks and it is replacing Angular and React in many cases. This brings in the topic of this blog ‘Vue.js is good, but is it better than Angular or React?


In case you’ve never heard or used Vue.js before, you are probably thinking: Come on! yet another JavaScript framework! We get it. However, Vue.js is not new in the custom software development domain. It was first released in 2013 and now it has 130549 stars on Github and downloaded a number of times this year.