Hadoop is divided into different modules, each of which delivers a distinct task crucial for a computer system and is uniquely designed for big data analytics. Apache Software Foundation developed this incredible platform. It is extensively utilized by worldwide developers to build big data Hadoop solutions amazingly and easily.

Big data offers several perks, some of them are; examining root causes of failures, recognizing the potential of data-driven marketing, improving and enhancing customer engagement, and much more. By offering multiple solutions in a single stream it helps in lowering the cost of the organization.

In various industries such as Retail, Manufacturing, Financial insurance, Education, Transportation, Agriculture, Healthcare, Energy, etc big data is utilized and that’s why it’s demand is expanding day by day. The Global Hadoop Market is envisioned to grow to $84.6 billion by 2021, with an expected CAGR of 63.4%.

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.

This is a post about first steps and first pitfalls in modernization of old enterprise application using "supersonic subatomic java" quarkus as it is positioned by RedHat.

Initial setup

In the end of 2019 I was invited to work in a project in our company, where an old monolithic application should be split into micro-services. Basic reasoning behind this decision was, that framework which is used in application is near to it's end-of-life. The application should be rewritten in any case. If it should be rewritten in any case, why not to split it into micro-services?

Since last 10 years, I was working mostly with java and we had in the project specialists with java knowledge, we have decided to give java-based frameworks a try for back-end functionality.
OK, let's use spring-cloud for that purpose, was our first thought. But then, we have had a look onto quarkus, which has been released in the end of 2019. We have decided to give it a try, keeping in mind building of native applications using GraalVM.

Native applications from our perspective could give us following benefits:

• shorten start time of container
• reduce resource consumption of container and application

We were aware about possible drawbacks of this solution:

• no experience in our team with quarkus framework
• significantly less amount of available feedback from community, since this is very young framework

Embox is a cross-platform, multi-tasking real-time operating system for embedded systems. It is designed to work with limited computing resources and allows you to run Linux-based applications on microcontrollers without using Linux itself. Certainly, the same as other applications, Embox couldn't escape from bugs. This article is devoted to the analysis of errors found in the code of the Embox project.

[Previously] I was talking about combinatorial complexity of integration tests in multicomponent systems, so let me remind. Let's build a simple system with only 3 components inside. It can be three independent modules and we want to provide some communication between them (message passing good enough for the purpose of the example) So we have 3! = 6 possible configuration to test. Before going deeper lets see how Quicksort fights a combinatorial complexity.

[Quicksort] reduces complexity on each pass of a given input. So far so good. Let's imagine example with 10 elements. How many possible permutations do we have? you are right: 10! ~= 3,6 * 10^6. So on the first pass the complexity will be reduced: 5!*5!, on the next pass it will be further reduced till 2!*3!*2!*3!… after logn times we will have 1!*1!*1!...1! = 1 possible position, and our given input is sorted. Gotcha. (attentive reader can mention about worst case scenario of quicksort, but lets discuss it someday) Coming back to our example…

There are many articles about Reactive Programming and different implementations on the internet. However, most of them are about practical usage, and only a few concern what Reactive Programming is, and how it actually works. In my opinion, it is more important to understand how frameworks work deep inside — spoiler: nothing actually complicated there — rather than starting to use a number of traits and operators meanwhile shooting yourself in the foot.

So, what is RxSwift Combine Reactive programming?

Last time we got acquainted with the structure of an important component of the shared memory — the buffer cache. A risk of losing information from RAM is the main reason why we need techniques to recover data after failure. Now we will discuss these techniques.

The log

Sadly, there's no such thing as miracles: to survive the loss of information in RAM, everything needed must be duly saved to disk (or other nonvolatile media).

Therefore, the following was done. Along with changing data, the log of these changes is maintained. When we change something on a page in the buffer cache, we create a record of this change in the log. The record contains the minimum information sufficient to redo the change if the need arises.

For this to work, the log record must obligatory get to disk before the changed page gets there. And this explains the name: write-ahead log (WAL).

In case of failure, the data on disk appear to be inconsistent: some pages were written earlier, and others later. But WAL remains, which we can read and redo the operations that were performed before the failure but their result was late to reach the disk.

Almost four years have passed since the PVS-Studio team checked the OpenToonz source code. This project is a very powerful tool for creating two-dimensional animation. Since the last check, with its help, such animated works as Mary and the Witch Flower, Batman-Ninja, Promare and others were created. As large studios continue using Toonz, why not check the quality of the source code again?

Instruments for Apple's Xcode is a tool for performance analysis of an iOS application. In 2018 Apple introduced Custom Instruments — an opportunity to expand the standard set of instruments for application profiling. When existing tools are not enough, you can create new ones yourself — it will collect, analyze and display the data the way you need.

Quantum Communications LLC creates some hacker-proof quantum encryption systems.

Let’s take a look at how they do it, and why their work matters.

New MS Edge is a promising Chrome flavour since Microsoft is really concerned with laptop battery life: most tests and benchmarks run against the «stock» browser in «stock» configuration. However, until recently it was hard for me to switch completely due to no «offline» support for Google office suite: doc, spreadsheet and slides. Fortunately, with the recent introduction of chrome extensions support it's now possible to put them offline with a few tricks!

For me, these two models are quite similar, but in fact they don’t have obvious characteristics to measure this similarity. These models have different numbers of vertices, edges and polygons. They are of different sizes, rotated differently and both have the same transforms (Location = [0,0,0], Rotation in radians = [0,0,0], Scale = [1,1,1]). So how to determine their similarity?

We have transcended into a world where most of the services that we want our needs available right in the comfort and confines of our homes! It is quite likely that an application addresses those needs.What makes these applications more interesting and relevant is the fact that they can identify the user and multiple attributes.

One of the significant attributes that can be identified by using mobile applications is the precise location of the user. The GPS, which was once confined to the military and aviation industry, has now been made available to almost every smartphone user. The GPS, combined with the mapping and navigation services by technology companies like Google and Apple, has made it extremely easy for the service provider to reach the location of the user.

Introduction

Quick Sort is one of the most famous and effective Sorting Algorithms. The comprehension of how it works will undoubtedly help you in your JavaScript learning. Also, questions on algorithms are popular in job interviews, so there is a big chance you will be asked to describe how Quick Sort works.

I’m sure that I convinced you that Quick Sort is important. Let’s start!

Even the most honest of scientists are regularly misled by their cognitive biases. They often go to great lengths to find proof for whatever seems logical, while dismissing evidence to the contrary.

Yet this issue is rarely discussed — because it remains an embarrassing subject.

5G ( Fifth Generation Wireless Cellular Network) is not just a possibility anymore. The forthcoming of 2020 has unfold avenues for 5G browser capabilities in smartphones.

With the recent 5G rollout, it has been predicted that over 1.4 billion devices will be running on the 5G network by 2025 — accounting for 15% of the global total.

Source: Google Images

I’m excited to announce experimental support for gRPC-Web with .NET. gRPC-Web allows gRPC to be called from browser-based apps like JavaScript SPAs or Blazor WebAssembly apps.

gRPC-Web for .NET promises to bring many of gRPC’s great features to browser apps:

• Strongly-typed code-generated clients
• Compact Protobuf messages
• Server streaming

About

This is small cross-platform linux-distro with zabbix server. It's a simple way to deploy powerful monitoring system on ARM platfornms and x86_64.

Worked as firmware (non-changeable systemd image with config files), have web-interface for system management like network settings, password and other.

Who is interested

• System admins/engineers who need to fast deploy of zabbix server.
• Everyone, who want to deploy zabbix on ARM.
• Enthusiasts

Each instance of a class in CPython created using the class syntax is involved in a cyclic GC mechanism. This increases the memory footprint of each instance and can create memory problems in heavily loaded systems.

Is it possible to use only basic reference counting mechanism when necessary?

Let's analyze one approach based on recordclass library that will help to create classes whose instances will only be deleted using the reference counting mechanism.

Note: this is translation from original post (in russian).

Last week, Visual Studio 2019 version 16.5 Preview 2 was released, bringing many new features and improvements for developers in Visual Studio to help you build better software faster. Please read some highlights of new features and improved developer experiences in this page.



Install this preview side-by-side with your Visual Studio release and try these highlighted features without replacing your current development environment.