4.1. Introduction

Over the past years, two important concepts have emerged in the computing world: Big Data and Cloud Computing. According to the NIST Big Data Public Working Group¹, Big Data is data that exceed the capacity or capability of current or conventional methods and systems. In [ZIK 11], IBM defines the term Big Data as information that cannot be processed or analyzed using traditional processes or tools. It is mainly based on the three-Vs model, where the three Vs refer to the volume, velocity and variety properties. We define these properties as follows:

• – Volume: this denotes the processing of large amounts of information. Over the past decades, several high technologies have appeared and they accompany people in their everyday life. If they can track and record something, they typically do it. For instance, simple actions (e.g. taking your smartphone out of your pocket, checking in for a plane, scanning your badge into work, buying a song on iTunes, etc.) generate...