Summing the Fibonacci Sequence

The golden ratio.

An image from nature (by Sustainable San Mateo). The golden ratio approximately (this is a topic for discussion) appears in here and is closely related to the Fibonacci sequence.

Consider the following problem (Project Euler, Problem #2):

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

Solving this problem by using a programming language is relatively easy and requires only looping through the sequence. How can you tackle this problem without the need for a computer? Spoiler alert: there is only one final step in which we will use a calculator.


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Project Euler using Scala: Problem #1

In this last post I gave a short introduction to Scala. In this article, I will show you the strength of Scala for solving one of the mathematical problems posted on Project Euler. The problem description is as follows:

Multiples of 3 and 5

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000.

I will first show you a naive approach and then I will show you a better approach.


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cpu sum

Monitoring your cluster in just a few minutes using ISA

Suppose you have a cluster. Suppose you would like to monitor your cluster as soon as possible without installing all kind of tools on the cluster. A new software package named ISA has been created which can do centralized monitoring for you! This article is a walkthrough for ISA and helps you setting up monitoring for your cluster in just a few minutes.


  • ISA can collect many node statistics such as CPU usage, memory usage and disk I/O.
  • It is easy to setup and it has flexible node configuration.
  • ISA ensures minimal influence for the node statistics.
  • No setup required on the nodes, the statistic management is done centrally.

In this tutorial, we will setup ISA and collect cluster statistics in a CSV.


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scala logo

Why Scala?

Scala is jet another programming language in the world of programming languages. Its first version was released in 2001 and was conceptually developed by Martin Odersky, a professor at the EPFL in Switzerland. Fun fact: one of his first projects was called Pizza and was a super set of the Java language. Later on, he developed Scala. The name and logo are easy to explain. First of all, Scala stands for SCalable LAnguage. Another translation: “Scala” means “staircase” in Italian. The logo is based on a particular staircase in one of the buildings of EPFL. Now we have had a decent introduction to Scala, we can start exploring the language itself. So what is Scala all about?

The inspiration for the Scala logo.

The inspiration for the Scala logo.


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