Three hundred and forty-eight years, six months, and nineteen days ago to-day, the Parisians awoke to the sound of all the bells in the triple circuit of the city, the university, and the town ringing a full peal. The sixth of January, 1482, is not, however, a day of which history has preserved the memory. There was nothing notable in the event which thus set the bells and the bourgeois of Paris in a ferment from early morning.

Let’s say we have written plenty of unit tests and also some integration tests covering some services. Would that be enough? The short answer is always “no”. You can have your application secured with as many unit tests as you want. You may have the confidence that your application is bulletproof with integration tests but in the end your web application must be loaded in a browser and there are a lot of layers that must match together when the client is calling the application that your backend is serving.

In a recent Lab, we set up sensors in our office to collect our own machine-generated data (see this blog post). For the follow-up lab, our team split up into three groups. Two of us set out to implement a nice real-time visualization of our data, another colleague investigated and benchmarked different document schemas for storing time series data in MongoDB (see this post on the MongoSoup blog), while the remaining two started analysing the data we collected.

Motivated by a current customer project (and the interesting nature of Big Data projects from industry in general), we decided to get our hands on sensor data. We wanted to learn how to handle, store and analyze it and what specific challenges sensor data presents.