One of our clients, a developer who used to work with php technologies for quite some time, frequently complained that with the transition to C# and .Net stack, he misses one of his favorite features from the php world — traits and he would like it very much to be able to use such functionality in .Net.

At one point, we decided to make him a present and implemented a proof of concept of similar functionality for C#.

To our surprise, it was quite easy to implement the PoC and the process of development was a lot of fun.

The step has been made. Not sure where to, but for sure from the point of no return. Keep calm and keep walking. It is about a time to look around and understand the smelly and slippery route before you. And what are those noisy creatures swarming around our fishy “innovative” design we called Mandelbrot blueprint. You don't get a buzzing-noise like that, just buzzing and buzzing, without its meaning something.

From this article, you will learn how to recover data from DVR and NVR video recorders. We will explore the peculiarities of how they store video files, why such files can be lost, and how they can be recovered. In the process, we’ll be using a IP network video recorder Hikvision DS-7104NI-Q1/4P.

Would you like to know how to use the LVM technology in Linux? How to create an LVM volume, how to configure and mount it in your operating system, how to add and remove disks, and how to recover the information you have accidentally deleted? In today’s article, you will find all of that – and even more.

Read this article to find out how to get your laptop ready for all kinds of tasks without paying extra. And how to configure Windows 10 in the best way. We will explore how to maintain Windows 10, configure system security and laptop power settings, what software to install and how to connect peripherals. Here is the best all-round guide for you!

This guide will show you how to recover lost data from a NAS storage system, with the example of D-link DSN-1100. Also, it will help you to retrieve information from the hard disks of an inoperable SAN device.

In this guide, we’ll explore the methods applied to create a software LVM RAID in Linux. Also, we will show you a simple solution to recover any data lost from an LV RAID 5 system as a result of accidental removal or unexpected drive failure.

In microservice world the problem of high load is exteremely big especially when we have a REST API which is accessed quite extensively. Why do we need throttling? The main answer is to decrease the load of the service at the moment.

Different frameworks have different solutions, mostly some additional libraries. Also there is a Guava RateLimiter and Bucket4J . What is interesting Spring MVC being one of the most popular solutions for building REST APIs (thank you Spring Boot) doesn't have any built in rate limiter. As for external solutions there not that many ways around.

Today, I would like to present a tiny experimental library specific for Spring MVC. It is called SpringRateLimitter. The library is very tiny ,works in runtime. The idea is to annotate entire rest controller or specific method , than count the number of incoming requests for the annotated URI and based on the values check if we exceed the allowed number of calls. In case of exceeding an HTTP error code 429 is thrown and after the throttling period is over , the endpoint is available again.

So How does it look like. As first step Maven dependency must be added

Here I am going to cover my own approach to compilation of mathematical functions into Linq.Expression. What we are going to have implemented at the end:

1. Arithmetical operations, trigonometry, and other numerical functions

2. Boolean algebra (logic), less/greater and other operators

3. Arbitrary types as the function's input, output, and those intermediate

Hope it's going to be interesting!

Architect. This word sounds so mysterious. So mysterious that to understand it you almost forced to add something. Like “System Architect” or “Program Architect”. Such addition does not make clearer, but for sure adds weight to the title. Now you know – that’s some serious guy! I prefer to make undoubtful and around 10 year ago added to my email signature “Enterprise Architect of Information Systems”. It’s a powerful perk. Like “Chosen One”. With architects it is always a matter of naming, you know. Maybe that is why the only way to become and architect is to be named as one by others. Like with vampires. One of them has to byte you! That is probably the easiest way to earn the title as there is no degree or school to grant you one. And if there’s a troubling title, somebody’s making a trouble, and the only reason for making a trouble that I know of is because you’re an Enterprise. Huge old and complex multinational corporation. Like a one-legged pirate. Strong and scary, but not a good runner. You own your ship, you had good days, you have some gold, you need new ways.

To get to new treasures and avoid losing second leg to piranha regulators and local business shark swarming waters near every enterprise ship – every pirate has a map. Map is a list of major features and requirements in desired order and priority.

The DHT system has existed for many years now, and torrents along with it, which we successfully use to get any information we want.

Together with this system, there are commands to interact with it. There are not many of them, but only two are needed to create a decentralized database: put and get.

Security. What does this word mean to you? Nowadays, companies spare no effort to ensure that their product is secured from hacking and all sorts of information leaks. PVS-Studio decided to help its users and expand the functionality in this area. Therefore, one of the main innovations of the upcoming release will be the introduction of analyzer new features which will ensure code safety and security. This article aims to present these features.

We work using Agile: Scrum, or Kanban, or any other extended project management way. Agile appeared in 2001 as a result of a long discussion between really smart guys. They just formed best practices of management into the shape of short documents - the Agile Manifesto. But what did they want to replace by the Agile way? Most of you may say that they wanted the Waterfall to go to the past. But what would you think if I tell you that the “classical” Waterfall had been a really rare thing even for those days?

Some of the features of your website require message queue integration. It is not a complex task for most developers. If you work with Azure infrastructure, you are able to choose Azure Service Bus as a queue engine. It sounds quite simple: just create Azure Resource, write some code and then be happy! But what would you say if the resources are limited? What will you do if there are several teammates in your team, and all of you have to debug queues at the same time? I try to give you a simple solution.

Most solutions to algorithmic problems can be grouped into a rather small number of patterns. When we start to solve some problem, we need to think about how we would classify them. For example, can we apply fast and slow аlgorithmic pattern or do we need to use cyclic sortpattern? Some of the problems have several solutions based on different patterns. In this series, we discuss the most popular algorithmic patterns that cover more than 90% of the usual problems.

It is different from High-School Algorithms 101 Course, as it is not intended to cover things like Karatsuba algorithm (fast multiplication algorithm) or prove different methods of sorting. Instead, Algorithmic Patterns focused on practical skills needed for the solution of common problems. For example, when we set up a Prometheus alert for high request latency we are dealing with Sliding Window Pattern. Or let say, we organize a team event and need to find an available time slot for every participant. At the first glance, it is not obvious that in this case, we are actually solving an algorithmic problem. Actually, during our day we usually solve a bunch of algorithmic problems without realizing that we dealing with algorithms.

The knowledge about Algorithmic Patterns helps one to classify a problem and then apply the appropriate method.

But probably most importantly learning algorithmic patterns boost general programming skills. It is especially helpful when you are debugging some production code, as it trains you to understand the execution flow.

Patterns covered so far:

Sliding Window I

Sliding Window II

Merge Intervals

Dutch National Flag

Matrix Spiral

Iterative Postorder Traversal

Bit Manipulation

Stay tuned :)

<Promo> If you interested to work as a backend engineer, there is an open position in my squad. Prior knowledge of Golang is not required. I am NOT an HR and DO NOT represent the company in any capacity. However, I can share my personal experience as a backend engineer working in the company. </Promo>

In this article, we discuss the postorder traversal of a binary tree. What does postorder traversal mean? It means that at first, we process the left subtree of the node, then the right subtree of the node, and only after that we process the node itself.

Why would we need to do it in this order? This approach solves an entire class of algorithmic problems related to the binary trees. For example, to find the longest path between two nodes we need to traverse the tree in a postorder manner. In general, postorder traversal is needed when we cannot process the node without processing its children first. In this manner, for example, we can calculate the height of the tree. To know the height of a node, we need to calculate the height of its children and increment it by one.

Let's start with a recursive approach. We need to process the left child, then the right child and finally we can process the node itself. For simplicity, let's just save the values into slice out.

Let me also say a word about properties. I'm going to consider a good use of them for immutable records in C#.

I am a big fan of code design, so in this article I want to cover existing approaches and show what, I think, is a better solution.

Having only programming background, it is impossible to develop software in some areas. Take the difficulties of medical software development as an example. The same is with music software, which will be discussed in this article. Here you need an advice of subject matter experts. However, it's more expensive for software development. That is why developers sometimes save on code quality. The example of the MuseScore project check, described in the article, will show the importance of code quality expertise. Hopefully, programming and musical humor will brighten up the technical text.

C# capabilities keep expanding from year to year. New features enrich software development. However, their advantages may not always be so obvious. For example, the good old yield. To some developers, especially beginners, it's like magic - inexplicable, but intriguing. This article shows how yield works and what this peculiar word hides. Have fun reading!

After 210 days, 600 commits, tens of debugging nights, and thousands of messages in the project chat, I finally released AngouriMath 1.2.

This is an open-source symbolic algebra library for C# and F#, maybe it is interesting for someone?