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You are standing at a red light at an empty intersection. How to make traffic lights smarter?

Reading time14 min
Views2.1K

Types of smart traffic lights: adaptive and neural networks

Adaptive works at relatively simple intersections, where the rules and possibilities for switching phases are quite obvious. Adaptive management is only applicable where there is no constant loading in all directions, otherwise it simply has nothing to adapt to – there are no free time windows. The first adaptive control intersections appeared in the United States in the early 70s of the last century. Unfortunately, they have reached Russia only now, their number according to some estimates does not exceed 3,000 in the country.

Neural networks – a higher level of traffic regulation. They take into account a lot of factors at once, which are not even always obvious. Their result is based on self-learning: the computer receives live data on the bandwidth and selects the maximum value by all possible algorithms, so that in total, as many vehicles as possible pass from all sides in a comfortable mode per unit of time. How this is done, usually programmers answer – we do not know, the neural network is a black box, but we will reveal the basic principles to you…

Adaptive traffic lights use, at least, leading companies in Russia, rather outdated technology for counting vehicles at intersections: physical sensors or video background detector. A capacitive sensor or an induction loop only sees the vehicle at the installation site-for a few meters, unless of course you spend millions on laying them along the entire length of the roadway. The video background detector shows only the filling of the roadway with vehicles relative to this roadway. The camera should clearly see this area, which is quite difficult at a long distance due to the perspective and is highly susceptible to atmospheric interference: even a light snowstorm will be diagnosed as the presence of traffic – the background video detector does not distinguish the type of detection.

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Total votes 3: ↑3 and ↓0+3
Comments0

2020 Network Security and Availability Report

Reading time9 min
Views974

By the beginning of 2021, Qrator Labs filtering network expands to 14 scrubbing centers and a total of 3 Tbps filtering bandwidth capacity, with the San Paolo scrubbing facility fully operational in early 2021;

New partner services fully integrated into Qrator Labs infrastructure and customer dashboard throughout 2020: SolidWall WAF and RuGeeks CDN;

Upgraded filtering logic allows Qrator Labs to serve even bigger infrastructures with full-scale cybersecurity protection and DDoS attacks mitigation;

The newest AMD processors are now widely used by Qrator Labs in packet processing.

DDoS attacks were on the rise during 2020, with the most relentless attacks described as short and overwhelmingly intensive.

However, BGP incidents were an area where it was evident that some change was and still is needed, as there was a significant amount of devastating hijacks and route leaks.

In 2020, we began providing our services in Singapore under a new partnership and opened a new scrubbing center in Dubai, where our fully functioning branch is staffed by the best professionals to serve local customers.

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Total votes 17: ↑17 and ↓0+17
Comments0

HDB++ TANGO Archiving System

Reading time3 min
Views1K
main

What is HDB++?


This is a TANGO archiving system, allows you to save data received from devices in the TANGO system.


Working with Linux will be described here (TangoBox 9.3 on base Ubuntu 18.04), this is a ready-made system where everything is configured.


What is the article about?


  • System architecture.
  • How to set up archiving.

It took me ~ 2 weeks to understand the architecture and write my own scripts for python for this case.


What is it for?


Allows you to store the history of the readings of your equipment.


  • You don't need to think about how to store data in the database.
  • You just need to specify which attributes to archive from which equipment.
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Rating0
Comments0

Agreements as Code: how to refactor IaC and save your sanity?

Reading time9 min
Views1.2K


Before we start, I'd like to get on the same page with you. So, could you please answer? How much time will it take to:


  • Create a new environment for testing?
  • Update java & OS in the docker image?
  • Grant access to servers?

There is the spoiler from the TechLeadConf. Unfortunately, it's in Russian


It will take longer than you expect. I will explain why.

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Total votes 3: ↑3 and ↓0+3
Comments0

The 2020 National Internet Segment Reliability Research

Reading time9 min
Views9.4K

The National Internet Segment Reliability Research explains how the outage of a single Autonomous System might affect the connectivity of the impacted region with the rest of the world. Most of the time, the most critical AS in the region is the dominant ISP on the market, but not always.

As the number of alternate routes between AS’s increases (and do not forget that the Internet stands for “interconnected network” — and each network is an AS), so does the fault-tolerance and stability of the Internet across the globe. Although some paths are from the beginning more important than others, establishing as many alternate routes as possible is the only viable way to ensure an adequately robust network.

The global connectivity of any given AS, regardless of whether it is an international giant or regional player, depends on the quantity and quality of its path to Tier-1 ISPs.

Usually, Tier-1 implies an international company offering global IP transit service over connections with other Tier-1 providers. Nevertheless, there is no guarantee that such connectivity will be maintained all the time. For many ISPs at all “tiers”, losing connection to just one Tier-1 peer would likely render them unreachable from some parts of the world.
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Total votes 26: ↑26 and ↓0+26
Comments0

Looking back at 3 months of the global traffic shapeshifting

Reading time9 min
Views3.2K
image
There would be no TL;DR in this article, sorry.

Those have been three months that genuinely changed the world. An entire lifeline passed from February, 1, when the coronavirus pandemics just started to spread outside of China and European countries were about to react, to April, 30, when nations were locked down in quarantine measures almost all over the entire world. We want to take a look at the repercussions, cyclic nature of the reaction and, of course, provide DDoS attacks and BGP incidents overview on a timeframe of three months.

In general, there seems to be an objective pattern in almost every country’s shift into the quarantine lockdown.
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Total votes 27: ↑27 and ↓0+27
Comments0

Bcache against Flashcache for Ceph Object Storage

Reading time11 min
Views2.5K

Fast SSDs are getting cheaper every year, but they are still smaller and more expensive than traditional HDD drives. But HDDs have much higher latency and are easily saturated. However, we want to achieve low latency for the storage system, and a high capacity too. There’s a well-known practice of optimizing performance for big and slow devices — caching. As most of the data on a disk is not accessed most of the time but some percentage of it is accessed frequently, we can achieve a higher quality of service by using a small cache.

Server hardware and operating systems have a lot of caches working on different levels. Linux has a page cache for block devices, a dirent cache and an inode cache on the filesystem layer. Disks have their own cache inside. CPUs have caches. So, why not add one more persistent cache layer for a slow disk?
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Total votes 16: ↑16 and ↓0+16
Comments0

How to test Ansible and don't go nuts

Reading time10 min
Views3.3K


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.

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Total votes 3: ↑3 and ↓0+3
Comments0

Why Enterprise Chat Apps isn’t built on Server-side Database like Hangouts, Slack, & Hip chat?

Reading time3 min
Views2.8K
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.
image
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Total votes 3: ↑3 and ↓0+3
Comments0

New action to disrupt world’s largest online criminal network

Reading time3 min
Views1.1K


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.
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Total votes 2: ↑2 and ↓0+2
Comments0

Monitor linux — cross platform firmware with zabbix server

Reading time4 min
Views2.4K

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
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Total votes 3: ↑3 and ↓0+3
Comments0

A Brief Comparison of the SDS Architectures for Virtualization

Reading time6 min
Views2.6K

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.

image

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:
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Total votes 2: ↑1 and ↓10
Comments0

Full disclosure: 0day vulnerability (backdoor) in firmware for Xiaongmai-based DVRs, NVRs and IP cameras

Reading time6 min
Views92K

This is a full disclosure of recent backdoor integrated into DVR/NVR devices built on top of HiSilicon SoC with Xiaongmai firmware. Described vulnerability allows attacker to gain root shell access and full control of device. Full disclosure format for this report has been chosen due to lack of trust to vendor. Proof of concept code is presented below.
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Total votes 19: ↑18 and ↓1+17
Comments15

Deploying Tarantool Cartridge applications with zero effort (Part 1)

Reading time8 min
Views1.9K


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.
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Total votes 29: ↑29 and ↓0+29
Comments0

Optimising server distribution across the racks

Reading time5 min
Views1.8K
Recently, a colleague asked me in a chat:

— Is there an article how to pack servers into the racks properly?

I realised that I'm unaware of it. So, I decided to write my text.

Firstly, this is an article about bare metal servers in the data centre (DC) facilities. Secondly, we estimate that there are a lot of servers (hundreds or thousands); the article doesn't make sense for fewer quantities. Thirdly, we consider that there are three constraints in the racks: physical space, electric power per each one, and cabinets stay in the rows adjacent to each other, so we can use a single ToR switch to connect servers in them.
The answer to the original question depends significantly...
Total votes 11: ↑10 and ↓1+9
Comments0

Lessons learned from testing Over 200,000 lines of Infrastructure Code

Reading time11 min
Views3.1K


IaC (Infrastructure as Code) is a modern approach and I believe that infrastructure is code. It means that we should use the same philosophy for infrastructure as for software development. If we are talking that infrastructure is code, then we should reuse practices from development for infrastructure, i.e. unit testing, pair programming, code review. Please, keep in mind this idea while reading the article.


Russian Version

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Total votes 5: ↑5 and ↓0+5
Comments4

Configuration of the Warnings Next Generation plugin for integration with PVS-Studio

Reading time3 min
Views1.7K

Picture 4


The PVS-Studio 7.04 release coincided with the release of the Warnings Next Generation 6.0.0 plugin for Jenkins. Right in this release Warnings NG Plugin added support of the PVS-Studio static code analyzer. This plugin visualizes data related to compiler warnings or other analysis tools in Jenkins. This article will cover in detail how to install and configure this plugin to use it with PVS-Studio, and will describe most of its features.
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Total votes 34: ↑33 and ↓1+32
Comments0

How we created IoT system for managing solar energy usage

Reading time5 min
Views1.3K

If you have no idea about the development architecture and mechanical/electrical design behind IoT solutions, they could seem like "having seemingly supernatural qualities or powers". For example, if you show a working IoT system to 18th century people, they'd think it's magic.This article is sort of busting such myth. Or, to put it more technically, about hints for fine-tuning the IoT development for an awesome project in solar energy management area.

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Total votes 9: ↑7 and ↓2+5
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

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