Prelude Ok, first of all: I know, I have already used the yoda picture below in the past, but even if I am not at all a fan of the Star Wars saga, I like it. ATTENTION! This is a deeply desperate post: don’t judge me, I’m sad, I’m alone, it’s raining, I don’t feel to have any perspective but there’s a positive thing: I’m still learning. So… let’s divide the complaints by sectors. ...
Introduction If you have an AWS account in Free Tier, you have (updated: March, 13th 2018) 750 hours/month to run EC2 (small ones) in your VPC. You also have a lot of other resources, such as AWS Lambda functions (I wrote about them here and here) and CloudWatch Events. In this article, I talk about smart resources handling and some trick - actually, not so smart XD - I setup to take the best from the services. Attention!!! Picture Spoiler ...
Introduction Recently I worked with AWS Lambda and API Gateway to extend my set of personal APIs and collect information from several sources. I wrote an article on that (if you want to have a look). In this article I will talk about the AWS Step Functions service that enable create finite states machines to easy coordinate the components of distributed applications and microservices using visual workflows. Why AWS Step Functions? Because they let me create a tool to gather movie titles in teather, search for reviews about each of them and make a basic sentiment analysis over the review to help me decide what’s worth watching at teather and what’s worth waiting for on Netflix :D More in general, with AWS Step Functions, you can build applications made of individual components that each perform a discrete function: this lets you scale and change applications quickly. Step Functions is a reliable way to coordinate components and step through the functions of your application. They provides a graphical console to arrange and visualize the components of your application as a series of steps. This makes it simple to build and run multistep applications. Step Functions automatically triggers and tracks each step, and retries when there are errors, so your application executes in order and as expected. Step Functions logs the state of each step, so when things do go wrong, you can diagnose and debug problems quickly. ...
Much more than a post What is the quantum theory? As said by quantumexperience official site by IBM, it’s an elegant mathematical theory able to explain the counterintuitive behavior of subatomic particles, most notably the phenomenon of entanglement. In the late twentieth century it was discovered that quantum theory applies not only to atoms and molecules, but to bits and logic operations in a computer. This realization has been bringing about a revolution in the science and technology of information processing: I decided to write some notes to better explain, from a physics-agnostic computer scientist’s point of view XD, what I understood - and it is certainly wrong - about Q until now and why I think it’s an amazing field for computer science. For skilled guys, here latex source (and here pdf pre-compiled version) that collect my personal notes about IBM Q platform, in general the quantum-computing world. I was also invited in Verona by the Quantum Research Group of the Department of Computer Science - why? don’t know, maybe the coolest guys were sick 😂 - to talk about the platform and we had a really interesting brain-storming conversation about a quantum version of the Tris game I am working on 😎 ...
Introduction In this article I will talk about my experience with AWS Lambda + API Gateway, GoLang (of course) and Grafana to build a sentiment analysis tool over customizable topics. Who should you read this post? Don’t know, maybe a CIO, a CTO, a CEO, a generic Chief or a MasterChef, for sure an AWS and GoLang fan like me. First of all: to better understand how to use Elasticsearch, read my previous post Elasticsearch over My home Network Attached Storage: it’s not so exciting as it seems, but you will have a general idea about what is Elasticsearch and how can you use it. Second: if you don’t know about AWS Lambda, study it. I personally believe that it represents one of the most interesting services currently offered by AWS: as they state, AWS Lambda lets you run code without provisioning or managing servers. You pay only for the compute time you consume and there is no charge when your code is not running. The amazing thing is that with a Free Tier trial you have 1 milions requests for free - O.O - to run code of any type of application or backend service - all with zero administration: you just upload your code - unfortunately the online editor for GoLang is not supported yet - and AWS Lambda1 takes care of everything required to run and scale your code with high availability. You can even set up your code to automatically trigger from other AWS services - as I have done with API Gateway - or call it directly from any web or mobile app. And…last but definetly not the least, why I’m writing this post!? Because starting from 15 January 2018, AWS Lambda support GoLang!!! ...
A journey through the network - Layer 2 A month ago I started to wrote some posts about the network. For those who missed the previous posts, the introduction and the physycal layer. For the previous post I had to go into details about how some parts of the physical layer work but, by going forward with the layers, concepts belonging to separate historical standards - OSI and IP - will intertwine and this entails some troubles from a logical point of view. I will try, as far as possible, to keep only the basic concepts of this layer: I also remember that this layer, together with the physical layer, are - at least in part - joined together in what is called the network access layer in the TCP / IP model. As a main source I use Computer Networks and TCP/IP Illustrated. In this article, I will talk about layer 1, the data link layer in the ISO / OSI stack. Enjoy the reading! ...
Introduction In the last months, I worked a lot with GoLang on several projects. Although I’m certainly not an expert, there are several things that I really appreciate about this language: first, it has a clear and simple syntax, and more than once I noticed that the style of the Github developers is very close to the style used in old C programs. From a theoretical point of view, GoLang seems to take the best of all worlds: there is the power of high-level languages, made simple by clear rules - even if sometime they are a little bit binding - that can impose a solid logic to the code. There is the simplicity of the imperative style, made of primitive types with the size in bits in their name, but without the boredom of manipulating strings as array of characters. However, two really useful and interesting features in my opinion are the goroutine and the channels. ...
Introduction I always owned a lot of hard drives: I don’t know why, I always used and still use to look for space to save my data. In the years, I started using disks, then I assembled a HP Proliant to be a Synology Based System - I don’t want to go the cloud because I’m stupid - and… in the last week, I decided to make order in a huge amount of files. The first thing you have to do when you are handling terabytes and terabytes of both well-ordered and no-ordered-at-all data is literaly pray that someone else, like a magician, or druid comes to you with a magic wand and fixes all the mess for free, in a way you do not know but you will like. This article is the right one if you don’t want to pray, you really don’t believe in miracle but you still need to order your stuff. I have done it using elastisearch and kibana! ...
Preamble Recently I became nostalgic and fascinated with stuff from the past, so I decided to create a Vagrantfile to work with FreeBSD1. Why FreeBSD? Because as a developer, I really like Docker and I started looking in the past to find its historical birth: in fact, as a concept, Docker is no so recent as you think, and I think it exists also because of the works of some other bigs from 80’, such as Poul-Henning Kamp2. Starting from its work and using a FreeBSD installation I did some experiments with jails, to understand better what they really are, how they works - how can you create what it will look like a vintage container - and why you should use them in a FreeBSD environment - at least, to learn something new. ...
A journey through the network - Layer 1 Before the Christmas holidays, I wrote an article about the network: yes. The network is that part of computer science that is no longer considered fundamental as it should, and I must admit that I learn it every day at my expense: as an old friend always says to me “the network is the concept on which everything is based, describes how the body works: after that, you can also become a gastroenterologist, but you will always need to know how the body works”. I think he’s right. As I was saying, I wrote an article about that: it’s a sort of overview and technical / historical introduction on the ISO / OSI and TCP / IP protocols. For those who missed the introduction, here the link. Despite my lack of experience, I promised myself, as far as possible, with the little time available, to retrace the various levels of the network from a theoretical point of view without going into too much detail, also trying to identify the most used commands, understand the level at which they operate and the functioning of the parameters supported by them. It took me a lot of time … but finally, the post on level one is ready. As a main source I use Computer Networks and TCP/IP Illustrated. In this article, I will talk about layer 0, the lowest in the ISO / OSI stack. Enjoy the reading! ...