computer express

Even such monsters of the cloud industry like Amazon problems occur with the equipment. In connection with the recent disruptions in the US East-1 data center, this article might be helpful. Options for building highly available systems on AWS. Overcoming outages Fault tolerance is one of the main characteristics of all cloud systems. Every day many applications are designed and deployed on AWS without taking into account this characteristic. The reasons for this behavior can vary from technical lack of knowledge in how to design a fault tolerant system up to the high cost of creating a full-fledged high-availability systems within AWS. This article highlights several solutions that will help to overcome the disruptions of hardware providers and create a more suitable solution within AWS infrastructure. The structure of a typical web application consists of the following levels: DNS, Load Balancer, web server, application server, database, cache. Let's take this stack a...

Company Xilinx quietly and without fanfare announced a product that can completely change the appearance and the development of modern radio receivers and transmitters. It's a small chip, which combines 90% treatment and formation of radio signals: the the programmable logic (FPGA) the processors for signal processing and user applications (two ARM a) the up to eight 12-bit ADC with sampling frequency up to 4 GHz (!), the up to eight 14-bit DAC with top frequencies up to 6.4 GHz (!). It seems we are in an era where the architecture of the transceiver becomes the same versatile architecture of the modern PC. Make SW, not HW! the the Era before Zynq' A bit of history. I represent a small team, the main activity of which during the last 10-15 years is R&D in the field of satellite navigation. What we do during this time! Developed new signals for GLONASS, was treated with all possible signals, simulated signals from a navigation system, sy...

/ > Often, while in public transport, in lectures or anywhere else away from the computer, I read the news and watch the necessary information on your Pocket PC. And mostly visited sites adapted for mobile devices. However, it just so happened that the notorious Habrahabr calculated for users a full PC and open Habr with "pickpocket" thing is painful and long. I know that the topic of the mobile version of this project was raised here repeatedly, but no one was able to offer normal solutions. And as we all know, to wait for the official implementation from the developers Habra useless. So I armed with my knowledge of PHP and regular expressions, he decided to make mobile version habrahabr . Turned out simple reader, but quick and convenient. It is possible to see the last 20 news from the home page 20 news of the new plus the division between personal and collective blogs. Picture in proportion shrink to the size of the PDA's screen in a vertical o...

the recruitment Market in Russia and CIS countries is now very developed and quite competitive, but, with rare exceptions, nothing better than a noticeboard with vacancies there. A job search often turns into a full-time job... We want to change the market. Now jobs find themselves a candidate. The fact that the best specialists looking for work through friends. FriendWork simplifies this method by using the app for Vkontakte. The mechanism is simple – a user logs on to the application that indicates their professional skills and interests, or places the vacancy. FriendWork compares the user data with the requirements of vacancies, the algorithm takes into account not only skills, but also other criteria such as education, place of residence etc. In case of a match, the seeker will receive a letter about a suitable vacancy. The search is performed only in the circle of friends posted the vacancy and their friends, so the more friends the user has in the application , t...

Want to share with you my last project. About a year ago I downloaded an app Aelios Weather for iPad . It hurt my eyes with its simplicity and unusual interface. And here's what happened: Look here As always, I was wondering how advanced HTML5, and is it possible to create something like that. At the core of the interface is the circle, which is kind of like a compass and clock in one. A compass can rotate in order to show the days of the week or time of day. It is also possible to see the time of sunrise and sunset. Inside the circle an arrow appears which is automatically sent to the largest population of item in this range. I tried to understand the interface. Then I started to search how to integrate Google Maps API. At the moment the website supports the following interface elements: the the and map it to the interface elements the hour circle with the arrow pointing to the most populated area under it the you can twist ...

in Russia Today, online sales are becoming more popular, competition in the market increases, the online stores have to fight not only for the amount of traffic, and quality: conversion of visitors into buyers. And for that you need to have a dialogue with the user. A modern solution for communication with customers — online-consultant. the History First contact with the online store was used most simple kinds of communication — phone, email and feedback form. But they all share one major drawback — the visitor has to make too many gestures: pick up the phone and call, to come in the mail and wrote a letter or even fill the form, leaving your e-mail is unclear who. Over time, began to appear the services of online consultations from the shops were required only to place a small code on the pages, and the eyes of the user appeared as the messenger directly in the browser setting on the end Manager. Well, not a miracle? will Omit the discussion of the stores where a...

it would Seem that we lucky to live in the greatest age of progress, modernism, and technological breakthroughs. To watch only, new nanotechnology in computer field it pushed into the distant background not only of the once greatest inventions, such as conventional wolfmane lamp, but the same trends, which are all about 5 years ago we waited with saliva in his mouth. To take even the normal Nokia N95, which I thirst for when it only just came out. It would seem that the miracle phone with GPS, giant screen and a lot of convenient (although the hold out from the word useful) features... but it was not there. Just a couple of years separates the status of "know-how" from the "junk". Here comes the most interesting point of my article is starting to read may think that the case in the eternal upgrade to hardy, and that further incur my plaintive words about how sad that everything passes so quickly. Yes a bit it was not there. No, in fact, the phenomenon of...