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Тarantool Cartridge: Sharding Lua Backend in Three Lines

Reading time8 min
Views2.5K
VK corporate blogDistributed systems*High performance*Tarantool*Lua*

In Mail.ru Group, we have Tarantool, a Lua-based application server and a database united. It's fast and classy, but the resources of a single server are always limited. Vertical scaling is also not the panacea. That is why Tarantool has some tools for horizontal scaling, or the vshard module [1]. It allows you to spread data across multiple servers, but you'll have to tinker with it for a while to configure it and bolt on the business logic.

Good news: we got our share of bumps (for example, [2], [3]) and created another framework, which significantly simplifies the solution to this problem.

Тarantool Cartridge is the new framework for developing complex distributed systems. It allows you to concentrate on writing business logic instead of solving infrastructure problems. Under the cut, I will tell you how this framework works and how it could help in writing distributed services.
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Total votes 26: ↑25 and ↓1+24
Comments0

How to Write a Smart Contract with Python on Ontology? Part 3: Runtime API

Reading time3 min
Views1.4K
DevOps*Python*CryptocurrenciesCryptography*Programming*
Tutorial
image

Introduction


Earlier, I have introduced the Ontology Smart Contract in
Part 1: Blockchain & Block API and
Part 2: Storage API
Now when you have an idea about how to call the relevant API for persistent storage when developing Python smart contract on Ontology, let’s go on to Runtime API (Contract Execution API). The Runtime API has 8 related APIs that provide common interfaces for contract execution and help developers get, convert, and validate data. Here’s a brief description of these 8 APIs:
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Rating0
Comments0

How to Write a Smart Contract with Python on Ontology? Part 2: Storage API

Reading time3 min
Views1.4K
DevOps*Python*CryptocurrenciesProgramming*Distributed systems*
Tutorial
image
This is an official tutorial published earlier on Ontology Medium blog
Excited to publish it for Habr readers. Feel free to ask any related questions and suggest a better format for tutorial materials

Foreword


Earlier, in Part 1, we introduced the Blockchain & Block API of Ontology’s smart contract. Today we will discuss how to use the second module: Storage API. The Storage API has five related APIs that enable addition, deletion, and changes to persistent storage in blockchain smart contracts. Here’s a brief description of the five APIs:
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Rating0
Comments0

PVS-Studio in the Clouds: CircleCI

Reading time11 min
Views744
PVS-Studio corporate blogDevelopment for Windows*DevOps*C++*

Picture 2

This is a new piece of our series of articles about using the PVS-Studio static analyzer with cloud CI systems. Today we are going to look at another service, CircleCI. We'll take the Kodi media player application as a test project and see if we can find any interesting bugs in its source code.
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Total votes 28: ↑26 and ↓2+24
Comments0

Automate SOAP client auto-generation routines with WSDL import for SBT and Scala

Reading time5 min
Views3.9K
DevOps*Java*Scala*

Working with SOAP often gets tricky, and dealing with WSDL might be a huge contribution to the complexity of this task. Really, it could be the least expected thing to face when you are into a modern & fancy language like for example, Scala, that is well known for its reactiveness and asynchronous way of dealing with requests. In fact, many of the software developers that have made their way into industry quite recently, might not even know about SOAP and WSDL protocols, and get quickly annoyed or even enraged when first trying to connect to such a legacy service. So, should we deprecate this altogether in favour of modern technology stack, or maybe there is a less painful solution?

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Total votes 3: ↑2 and ↓1+1
Comments0

Azure Media Services' new AI-powered innovations

Reading time6 min
Views746
Microsoft corporate blogMicrosoft Azure*Cloud computing*Cloud services*Media management*
At Microsoft, our mission is to empower every person and organization on the planet to achieve more. The media industry exemplifies this mission. We live in an age where more content is being created and consumed in more ways and on more devices than ever. At IBC 2019, we were delighted to share the latest innovations we’ve been working on and how they can help transform your media workflows. Read on to learn more.

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Total votes 2: ↑1 and ↓10
Comments0

Quintet instead of Byte — data storage and retrieval approach

Reading time13 min
Views1.8K
Data storage*Programming*System Analysis and Design*SQL*IT Standards*
Quintet is a way to present atomic pieces of data indicating their role in the business area. Quintets can describe any item, while each of them contains complete information about itself and its relations to other quintets. Such description does not depend on the platform used. Its objective is to simplify the storage of data and to improve the visibility of their presentation.



We will discuss an approach to storing and processing information and share some thoughts on creating a development platform in this new paradigm. What for? To develop faster and in shorter iterations: sketch your project, make sure it is what you thought of, refine it, and then keep refining the result.

The quintet has properties: type, value, parent, and order among the peers. Thus, there are 5 components including the identifier. This is the simplest universal form to record information, a new standard that could potentially fit any programming demands. Quintets are stored in the file system of the unified structure, in a continuous homogeneous indexed bulk of data. The quintet data model — a data model that describes any data structure as a single interconnected list of basic types and terms based on them (metadata), as well as instances of objects stored according to this metadata (data).
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Total votes 8: ↑8 and ↓0+8
Comments2

How to Write a Smart Contract with Python on Ontology? Part 1: the Blockchain & Block API

Reading time5 min
Views3.1K
Distributed systems*CryptocurrenciesPython*
From sandbox
image

This is an official tutorial published earlier on Ontology Medium blog
Excited to publish it for Habr readers. Feel free to ask any related questions and suggest a better format for tutorial materials

Foreword


In this article, we will begin to introduce the smart contract API of Ontology. The Ontology’s smart contract API is divided into 7 modules:


In this article, we will introduce the Blockchain & Block API, which is the most basic part of the Ontology smart contract system. The Blockchain API supports basic blockchain query operations, such as obtaining the current block height, whereas the Block API supports basic block query operations, such as querying the number of transactions for a given block.

Let’s get started!

First, create a new contract in SmartX and then follow the instructions below.

1. How to Use Blockchain API


References to smart contract functions are identical to Python’s references. Developers can introduce the appropriate functions as needed. For example, the following statement introduces GetHeight, the function to get the current block height, and GetHeader, the function to get the block header.
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Total votes 20: ↑18 and ↓2+16
Comments0

Tutorial For Creating Blockchain Solution on Hyperledger Composer

Reading time7 min
Views3K
Decentralized networks*Development of mobile applications*Mobile applications design*System Analysis and Design*


Due to modern business demands, IBM joined hands with other companies to develop an open-source business blockchain network called Hyperledger Fabric project that is touching the sky. Due to modular architecture, digital keys, and on-demand data retrieval, hyperledger fabric is regarded as the base for the world’s future modular architecture blockchain-based apps. Further benefits of Hyperledger Fabric are given below to facilitate your interpretation.
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Total votes 7: ↑6 and ↓1+5
Comments0

Vepp — ISPsystem’s new server and website control panel

Reading time9 min
Views1.2K
ISPsystem corporate blogWebsite development*Hosting


Vepp is our new panel for managing servers and websites. At first, we just wanted to transform the interface of ISPmanager 5 but at the designing phase, we figured that (changing) the interface is not enough. We have to change the approach to modern user’s needs and tasks. As a matter of fact, it meant that we had to create a whole new product.


In the article, we’ll explain why we couldn’t make do with only cosmetic changes to ISPmanager 5 and show the result of the global overhaul.

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Total votes 6: ↑6 and ↓0+6
Comments0

DPKI: Addressing the Disadvantages of Centralized PKI by Means of Blockchain

Reading time15 min
Views3.1K
ENCRY corporate blogDecentralized networks*Information Security*Cryptography*Network technologies*


Digital certificates are one of the most commonly known auxiliary tools that help protect data across public networks. However, the key disadvantage of this technology is also commonly known: users are forced to implicitly trust certification authorities which issue digital certificates. Andrey Chmora, Technology and Innovations Director at ENCRY, suggested a new approach for building a Public Key Infrastructure (PKI) to eliminate the existing disadvantages using the distributed ledger (blockchain) technology.
Let's begin with the basics.
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Total votes 4: ↑3 and ↓1+2
Comments0

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

Reading time11 min
Views3.2K
Configuring Linux*DevOps*IT Infrastructure*IT systems testing*


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
PVS-Studio corporate blogIT systems testing*IT Infrastructure*Development Management*DevOps*

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

Bypassing LinkedIn Search Limit by Playing With API

Reading time7 min
Views17K
API*Data storage*JavaScript*Reverse engineering*Social networks and communities
Translation
[Because my extension got a lot of attention from the foreign audience, I translated my original article into English].

Limit


Being a top-rated professional network, LinkedIn, unfortunately, for free accounts, has such a limitation as Commercial Use Limit (CUL). Most likely, you, same as me until recently, have never encountered and never heard about this thing.

image

The point of the CUL is that when you search people outside your connections/network too often, your search results will be limited with only 3 profiles showing instead of 1000 (100 pages with 10 profiles per page by default). How ‘often’ is measured nobody knows, there are no precise metrics; the algorithm decides it based on your actions – how frequently you’ve been searching and how many connections you’ve been adding. The free CUL resets at midnight PST on the 1st of each calendar month, and you get your 1000 search results again, for who knows how long. Of course, Premium accounts have no such limit in place.

However, not so long ago, I’ve started messing around with LinkedIn search for some pet-project, and suddenly got stuck with this CUL. Obviously, I didn’t like it that much; after all, I haven’t been using the search for any commercial purposes. So, my first thought was to explore this limit and try to bypass it.

[Important clarification — all source materials in this article are presented solely for informational and educational purposes. The author doesn't encourage their use for commercial purposes.]
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Total votes 10: ↑9 and ↓1+8
Comments3

How we created IoT system for managing solar energy usage

Reading time5 min
Views1.3K
Big Data*IT Infrastructure*System Analysis and Design*IOTSmart House

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
Views3.6K
Qrator Labs corporate blogNetwork technologies*IT Infrastructure*IPv6*Decentralized networks*


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

PVS-Studio 7.04

Reading time8 min
Views918
PVS-Studio corporate blogDevOps*C++*C*
Picture 4

Summer is not only a holiday season, but also time of fruitful work. Sunny days are so inspiring that there's enough energy both for late walks and large code commits. The second summer PVS-Studio 7.04 release turned out to be quite large, so we suggest for your attention this press release, in which we'll tell you about everything.
Read more →
Total votes 21: ↑19 and ↓2+17
Comments1

Analysis of the Apache Dubbo RPC Framework by the PVS-Studio Static Code Analyzer

Reading time9 min
Views1.5K
PVS-Studio corporate blogApache*Java*Open source*Programming*

Picture 2

Apache Dubbo is one of the most popular Java projects on GitHub. It's not surprising. It was created 8 years ago and is widely applied as a high-performance RPC environment. Of course, most of the bugs in its code have long been fixed and the quality of the code is maintained at a high level. However, there is no reason to opt out of checking such an interesting project using the PVS-Studio static code analyzer. Let's see how it turned out.
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Total votes 25: ↑24 and ↓1+23
Comments0

Smart Manufacturing and Industry 4.0: Three Main Technological Trends

Reading time2 min
Views1.1K
IT Infrastructure*


In recent years we've witnessed massive technological improvements and innovations that re-shaped how industrial objects look like and work. This shift was called an Industry 4.0, i.e., a new phase in the Industrial Revolution that focuses heavily on connectivity, automation, machine learning, and real-time data, all for increasing the productivity, fueling effectiveness of business processes and lifting up the level of security.
Read more →
Total votes 2: ↑2 and ↓0+2
Comments0
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