Posts

  • Implementing Time Series in MongoDB

    I came recently to design a solution for MongoDB to store information that has time as the main axis of analysis. This information should be stored in a way that is easy enough to query and aggregate using many different time granularity (monthly, weekly, daily, ...). Information should also be stored in a way that does not consume too much disk space and is optimal in performance for MongoDB to maintain. In a word, I need to transform MongoDB in a Time series database. [continue...]
  • Code looks like a Chain

    As Aerosmith sang many years ago, “Code looks like a Chain.” No? They didn't say that? Maybe I'm remembering it wrong. Well, as you might have guessed, in this post, we'll talk about the Chain of Responsibility design pattern. This pattern is not one of the more popular ones, at least among the patterns defined by the Gang of Four, but modern dependency injection frameworks give us the possibility to implement it in a smart, and fresh way. Let’s see how. [continue...]
  • Scala is dead, long live Scala!

    Recently I came across yet another post about the adoption of Scala in the IT world nowadays. The article is 'The Rise and Fall of Scala' on DZone. In that post the author describes the reasons of the failure of the Scala language in becoming the next big general purpose programming language. But, are we sure that authors of Scala ever pretend the language to be used by every developer on the Planet? I don't think so. [continue...]
  • Try again, Apache Spark!

    It's been more than a year since I've started working on my first Big Data project. In this project we chose Apache Spark as batch processing framework. Using Apache Spark throws you in a functional, distributed and asynchronous programming world. While you have not to worry about the distributed adjective, because Spark hides you every problem related to it, the functional and asynchronous adjectives make things more complex with respect to the error handling process. Let's explain why. [continue...]
  • Resolving your problems with Dependency Injection

    'No Silver Bullet' wrote Brooks in the far away 1986. The history of software engineering proved him right, there is no doubt. Through the past years, hundreds of theories, patterns, frameworks, technologies risen as fast as they successively fallen. Dependency injection broke down the developer community from its definition. In this post I will introduce the pattern, giving the basis for developing a discussion on pattern pros and cons in the next post of this series. [continue...]
  • A new way to err, Apache Spark

    Apache Spark is a library that let you write code that will be executed in a distributed fashion as a simple single threaded program. Spark will make the dirty job for you: it will distribute the code and the execution, manage remote objects for you, optimize the algorithm for you. However, be aware: there is no kind of magic behind Spark. If you do not deeply understand the logic behind it, you will discover new way to loss your time searching for incomprehensible bugs. [continue...]
  • Actorbase or "the persistence chaos"

    You know, everybody out there is talking about Big data, NoSQL databases, reactive programming and so on. There are a lot of buzzwords that are constantly used in this era and the above are some of these. What if someone decide to put some of those buzzword together? What if we couple NoSQL databases and the actor model? Actorbase is a NoSQL database that uses the actor model as its internal reference model. [continue...]
  • Immutability = Thread-safety

    No, there is not a typo in the title of this post. It is a distorted quotation from the Slipknot song 'People equal s**t'. And more or less this was my reaction when I discovered that in Java immutability is not equals to thread-safety. Not always. Let me explain why. [continue...]
  • You shall not comment!

    When I was attending the course of Computer Science at the University they told me that I have to document my code. In this way, the developers that would come after me could understand easily the code I had wrote. Writing good comments is an hard task, if it is possible at all. In this article I will try to explain you why. [continue...]
  • The Good, the Bad and the Singleton

    If you search for the word Singleton on Google, you will probably come up with a bunch of rants about the fact that this design pattern is the absolute evil on the earth. Is it true? Or is this design pattern totally misunderstood by developers? In this series of articles I will try to analyze the reasons that stay behind those rants and I will try to give my point of view on the issue. [continue...]
  • Handling dynamic id objects in Rational Functional Tester

    Functional testing is an discipline that is becoming more and more requested in software industry. In this article we will focus on Rational Functional Tester and on a problem that affects it: recognition of HTML objects with a dynamic id. [continue...]
  • A (too) short introduction to Scala

    I recently had an introductory talk on the Scala programming language. the aim of the talk was not to be a comprehensive presentation of the Scala programming language. The aim was to introduce the Scala language, putting a stress on the features that made it one of the heirs to the throne of programming. [continue...]
  • Eat that cake!

    We know it, managing dependencies between software components within a project of magnitude rather than trivial could become a hell if not planned properly Scala provides a mechanism to resolve dependencies similar to DI, the *cake pattern*. Unlike DI pattern in other languages, such as Java, C++, etc ... the cake pattern can be used directly with language constructs available in Scala. [continue...]
  • Introducing myself...

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