April 14th, 2014



Lauri Apple


Lauri Apple Technology Evangelism Specialist at Gilt


In late March Gilt’s Dublin team partnered up with Dublin-based consultancy DigBigData to offer a free Cassandra workshop near our Dublin office. Twenty-five technologists from Gilt and other area companies came together for a full day of hands-on learning, experimentation and fun taught by DigBigData’s Niall Milton (an official MVP for Apache Cassandra). Gilt’s Cassandra workshop was part of our free tech education initiative, by which we offer full-day tech courses at no charge to both Gilt and non-Gilt technologists. Since launching this program in June 2013, we’ve offered classes in Scala, Hadoop, R, Machine Learning and other topics of interest to us–and more courses are on the way. Nearly half of our Dublin team signed up for the Cassandra workshop, while other attendees came from Workday, Dun & Bradstreet and other companies.

Gilt currently doesn’t use Cassandra in production, but as NoSQL enthusiasts and open source advocates we’re quite interested in learning more about how it works. Several workshop attendees had prior experience working with older versions of Cassandra and wanted a quick refresher. Others on the team had very minimal experience, or had read the Dynamo and BigTable papers but never tried using it. Because everyone in the class was an experienced technologist, however, getting started posed very few problems.

The biggest challenge for me was switching to working with a column-based database, having always worked with traditional row-based databases,” says Gilt Lead Software Engineer John Kenny. Adds Emerson Loureiro, another Gilt engineer: “I had no prior experience with Cassandra itself, but was familiar with most of the concepts behind it, so getting started was quite OK. To me it was more about looking at data modeling from a different perspective.”

After giving an introduction to Cassandra, Milton split the course into six teams who then set to work on building a variety of applications. Over the course of the day, teams asked lots of questions about performance, replication, fault tolerance, and other nuts-and-bolts aspects of Cassandra. By workshop’s end, the teams had created several exciting projects, including a CPU temperature monitor, a tweet sentiment analyzer, a multi-player, web-based game, and BigChat—a SnapChat-inspired service.

Though some of the students said they’d have benefited from more time to develop their projects, others were pleased with the end results of their work. “I think it was a nice use case for Cassandra,” says Emerson about the course. “It gave me the opportunity to stress the bits we had learned in the course and to get some more hands-on experience.”