Intro

Like I said earlier in previos articles, Buildroot is a great system for embedded Linux development. But sometimes strange things can happen.

Once upon a workday, I got the following task: add printing system in firmware (Kraftway terminal Linux next generation). Ok, so I had to add cups + cups filter and to build firmware. I set a postscript-printer and got an error "Filter failed". Trivial tasks turned into serious work.

In this article, I wrote my own way of solving this problem. It may be useful for other developers and IT-specialist and, also, for a deeper understanding of the Buildroot.

If you are a Buildroot beginner, I recommend reading my previous articles.

Update 1 may 2020

Revisioned versions of this patches applied to master.

We have recently talked about how to deploy a Tarantool Cartridge application. However, an application's life doesn't end with deployment, so today we will update our application and figure out how to manage topology, sharding, and authorization, and change the role configuration.

Feeling interested? Please continue reading under the cut.

Backing up valuable data is a proven practice, but what if we need to continue work immediately after a natural disaster or other disruptive events, and every minute is important? Our team at Acronis decided to see how quickly we can start an operating system. This is our first post from the Active Restore series. Today I will tell you how we launched our project with Innopolis University, which solutions were studied, and what we are working on today. All the details are under the Cut.

That, we must say, is the unique story so far.

Here’s the beginning: for approximately an hour, starting at 19:28 UTC on April 1, 2020, the largest Russian ISP — Rostelecom (AS12389) — was announcing prefixes belonging to prominent internet players: Akamai, Cloudflare, Hetzner, Digital Ocean, Amazon AWS, and other famous names.

Before the issue was resolved, paths between the largest cloud networks were somewhat disrupted — the Internet blinked. The route leak was distributed quite well through Rascom (AS20764), then Cogent (AS174) and in a couple of minutes through Level3 (AS3356) to the world. The issue suddenly became bad enough that it saturated the route decision-making process for a few Tier-1 ISPs.

It looked like this:



With that:

СOVID-19 and Internet

Recent events caused by coronavirus spread have highlighted quite a few problem areas in society, economics, technology… And it’s not only about the panic, which is inevitable and will come back with any following global issue. But it is really about the consequences: crowded hospitals, empty shelves in supermarkets, people having to stay at home and use up the Internet which turns out to not be enough for everyone who’s going through the hard days and nights of #stayathome.

What already happened

What is this article about?

In this article, I will tell about my participation in the first (out of two so far) Telegram blockchain contest. I didn't win any prize. However, decided to combine and share the unique experience from the start to finish line, so my observations could help anyone who is interested.

Since I didn't want to write some abstract code, instead make something useful. I created instant lottery smart-contract and website which shows smart-contract data directly from Telegram Open Network (TON) avoiding transitional storage.

The article will be particularly useful for those, who want to write their first smart-contract in TON but has difficulties where to start.

Using the lottery smart-contract as an example, I will show the path from the environment set up till publication of the smart-contract and its interaction. Moreover, I will create a website that will show smart-contract data.

I'm a DevOps Teamlead at Miro. Our service is a high-load one: it is used by 4 million users worldwide, daily active users - 168,000. Our servers are hosted by Amazon and located in a single Ireland region. We have more than 200 active servers, with almost 70 of them being database servers.

The service's backend is a monolith stateful Java application that maintains a persistent WebSocket connection for each client. When several users collaborate using the same whiteboard, they see changes on the whiteboard in real-time. That's because we write every change to a database, resulting in ~20,000 requests per second to the databases. During peak hours, the data is written to Redis at ~80,000–100,000 RPS.

I am going to speak about why it is important to us to maintain PostgreSQL high availability, what methods we've applied to solve the problem, and what results we've achieved so far.

One of the most significant tools for any organization to smoothen their collaborative world is only through a real-time chat application whether the conversation takes place on mobile or desktop. Hangouts, Slack and Hipchat have been in action for businesses to establish a decent conversation between their internal employees and clients right from small-scale to enterprises.

Those big players come into play where there requires team collaboration. The big players are built on a server-side database where the messages shared from one device to another is stored in their server database. Ultimately, this results in storing a huge amount of data within the server-side database (Cloud-database).

The consumption of cloud storage will be pretty high. The client-side database is more efficient where the messages relayed is stored in the client device. The messages will be queued to minimize the consumption of data in the server.

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.

Looking to build a new app, develop and test, or run small production workloads with Azure Cosmos DB? Our new Free Tier makes it easy to get started with no cost and save money as you build and grow new apps.



With Azure Cosmos DB Free Tier enabled, you’ll get the first 400 RU/s throughput and 5 GB storage in your account for free each month, for the lifetime of the account. That means that you can start small and grow with confidence, knowing your app will be running on a high-performance database service. You’ll only pay if your account exceeds 400 RU/s and 5 GB. Additionally, if your app has a lot of containers you can create up to 25 containers in a shared throughput database and have them all share the free 400 RU/s. You can have up to one free tier Azure Cosmos DB account per Azure subscription.

Today, Microsoft and partners across 35 countries took coordinated legal and technical steps to disrupt one of the world’s most prolific botnets, called Necurs, which has infected more than nine million computers globally. This disruption is the result of eight years of tracking and planning and will help ensure the criminals behind this network are no longer able to use key elements of its infrastructure to execute cyberattacks.

A botnet is a network of computers that a cybercriminal has infected with malicious software, or malware. Once infected, criminals can control those computers remotely and use them to commit crimes. Microsoft’s Digital Crimes Unit, BitSight and others in the security community first observed the Necurs botnet in 2012 and have seen it distribute several forms of malware, including the GameOver Zeus banking trojan.

Commercial and educational customers moving to the cloud with Microsoft 365 have long needed a simple, easy print experience for their employees. Today we are happy to announce a private preview of Universal Print, a Microsoft cloud-based print infrastructure that will enable a simple, rich and secure print experience for users and help reduce time and effort for IT.

Today, we’re happy to announce the Generally Available (GA) release of PowerShell 7.0! Before anything else, we’d like to thank our many, many open-source contributors for making this release possible by submitting code, tests, documentation, and issue feedback. PowerShell 7 would not have been possible without your help.

What is PowerShell 7?

For those unfamiliar, PowerShell 7 is the latest major update to PowerShell, a cross-platform (Windows, Linux, and macOS) automation tool and configuration framework optimized for dealing with structured data (e.g. JSON, CSV, XML, etc.), REST APIs, and object models. PowerShell includes a command-line shell, object-oriented scripting language, and a set of tools for executing scripts/cmdlets and managing modules.

Chances are that while you've been using FileZilla you've also come across the ECONNREFUSED — connection refused by a server error. If that's the case — great that you've found this tutorial! I am going to show you three methods that might help you with resolving this FTP error.

Introduction

In my previous article (Monitor linux) I wrote, what is this distro and how it works. Now i will write how to do it. It's may be interesting for everyone, who want to study buildroot.

Target goals

The result we get from article is the following:

• Firmware (non-volatile image with restorable config)
• Easy management via web-interface
• Cross-platform (qemu x86_64, arm-based SBC like rasberry 4, beagle bone black and asus tinker board)
• Support without extra effort

The explosion of open source and issues related to it

The amount of open source or other third party code used in a software project is estimated as 60-90% of a codebase. Components, such as libraries, frameworks, and other software modules, almost always run with full privileges. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications using components with known vulnerabilities may undermine application defences and enable a range of possible attacks and impacts.



Conclusion: even if you perform constant security code reviews, you still might be vulnerable because of third-party components.

Some have tried to do this manually, but the sheer amount of work and data is growing and is time consuming, difficult, and error prone to manage. It would require several full time employees and skilled security analysts to constantly monitor all sources to stay on top.

Hi Habr,

I'm Artyom Karamyshev, a system administration team leader at Mail.Ru Cloud Solutions (MCS). We launched many products in 2019. We've aimed to make API services easily scalable, fault-tolerant, and ready to accommodate rapid growth. Our platform is running on OpenStack, and in this article, I describe all the component fault tolerance issues that we've resolved.

The overall fault tolerance of the platform is consists of its components fault tolerance. So, I'm going to show you step by step tutorial about all levels where we've found the risks.

We continue making the use of PVS-Studio more convenient. Our analyzer is now available in Chocolatey, the package manager for Windows. We believe this will make it easier to deploy PVS-Studio, particularly in cloud services. So right off the bat, we also checked the source code of the same Chocolatey. Azure DevOps took on the role of the CI system.

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

The search for a suitable storage platform: GlusterFS vs. Ceph vs. Virtuozzo Storage

This article outlines the key features and differences of such software-defined storage (SDS) solutions as GlusterFS, Ceph, and Virtuozzo Storage. Its goal is to help you find a suitable storage platform.

Gluster

Let’s start with GlusterFS that is often used as storage for virtual environments in open-source-based hyper-converged products with SDS. It is also offered by Red Hat alongside Ceph.
GlusterFS employs a stack of translators, services that handle file distribution and other tasks. It also uses services like Brick that handle disks and Volume that handle pools of bricks. Next, the DHT (distributed hash table) service distributes files into groups based on hashes.
Note: We’ll skip the sharding service due to issues related to it, which are described in linked articles.



When a file is written onto GlusterFS storage, it is placed on a brick in one piece and copied to another brick on another server. The next file will be placed on two or more other bricks. This works well if the files are of about the same size and the volume consists of a single group of bricks. Otherwise the following issues may arise: