The 7th meetup or Waiting for CSI Ixelles

Three weeks ago our litte community on bigdata had their 7th meetup in Brussels. We think it is a good idea to hold our meetups in different cities, since we are the Belgian bigdata community. (If you can host a meetup in your city, please contact us!). Next to the typical  evening traffic chaos and a meeting of all European prime ministers there was a crime scene (some sort of knife fight) next to our meeting place, which caused some of our participants to arrive a bit later, than planned.

Nevertheless did we have a good schedule, which consisted out of two talks with lots of good interaction between the speakers and the audience.

The first talk was about storm a distributed realtime processing framework coming out of twitter. Daan Gerrits gave an introduction into storm and walked us through an example application he had created for this meetup.

The second talk (by me) was about apache giraph a graph processing framework on top of apache hadoop.

If you have been to one of our meetings and you liked it, please spread the word, leave comments here, and consider the “call for papers” for our 8th meetup in July open!

Real estate project – Minutes from kickoff

On Monday the 21st of November, we kicked off our first project using historic sales data from a real estate website  (meetup).

Interesting discussions throughout the evening lead us to define two paralel tracks. On the one hand, we will try to come up with a semi-structured model for real estate data. On the other hand, we will attempt to apply data analytics on real estate data using algorithms provided by the Apache Mahout community.

Besides being of interest to the community, we reasoned that a semi-structured data model would support integration of real estate data with orthogonal information derived from e.g. OpenStreetMap or OpenBelgium. This will enable us to enrich the existing data with things like

  • distance to n cities,
  • a ‘green index’ that correlates how far a real estate property is located from a nearby forest, or
  • a ‘density index’ that ties in with the number of houses that are for sale at the moment in a radius of 1, 2, 4, 8 or 16 km .

We thought of using HBase or Cassandra as datastores to address this task, but we will only decide this during follow-up meetings. Remembering the interests poll from the first meetup, there will hopefully be quite a few members from the community to elaborate this track of the real estate project.

The second track of the real estate project on the other hand aims to attract social interest by producing insights that are more relevant to a wider audience then just our community. As such we touched three topics for data analytics we could elaborate depending on their feasibility.

  1. Prediction of the price and time of the sale
    Based on archives from real estate companies, we will evaluate how well the price and time of the sale of a house can be predicted. For the suspicious readers, have a look a the Zestimate® price from the real estate agency from the U.S..
  2. Text mining on free text descriptions
    It’s obvious that a plastic door correlates to a cheap house, while a granite kitchen correlates to expensive houses. But what other vocabulary-based associations can we derive by performing text mining analysis on the free text fields specified by the seller? (cfr. Freakonomics chapter 2)
  3. Recommendation engine for similar real estate properties
    Finally, by analyzing traffic logs from a real estate website, we should be able to build a recommendation engine that guides the visitor’s to related houses on sale. Think of how you search for a Canon 550D, and you will surely see the camera bag as well.


Keep your eyes on the meetup site and, if interested, join the next events on the real estate project!


2nd Meetup – BigData project

On Wednesday August 24th 2011, we had our second meetup. As some people cancelled at the last moment, the crowd was not as large as for our first meetup: now, there were just 6 of us.

This meetup was the first time we organised our get-together as an open discussion. Davy Suvee came up with that idea and apparently everybody present enjoyed this format very much. This article is a synopsis of the topics discussed.

On the look for a Big Data project

One of the major demands from our community members is to work together on some specific Big Data project to gain hands on experience. In this respect the Big Data Wars thread was started on our groups page. However, instead of organizing a true public challenge, it would be easier and more instructive to just participate on a challenge as a team or to look for a specific project that we can implement ourselves. They are outlined underneath.

We decided to create a bitbucket account where we can define, plan, work and code on these projects.

Wikipedia’s Participation Challenge

A few days after Daan Gerits launched the BigData Wars idea on the group page, Nathan Bijnens referred to the Wikipedia’s Participation Challenge as a good fit for a project. You can read the full description on the page, but the idea is to build a predictive model that allows the Wikimedia Foundation to understand what factors determine editing behaviour and to forecast long term trends in the number of edits to be expected on A random sample from the English Wikipedia dataset from the period January 2001 – August 2010 serves as training dataset for the predictive model.

Appealing to this challenge is that it is a very specific problem description,  encompassing quite a large fraction of the big data complexity:

  • data availability,
  • datastore modelling,
  • defining secondary data,
  • deriving sampled test data,
  • building predictive models using various approaches, technologies and algorithms.

However, as the deadline for the project is very close, i.e. Tuesday 20 September 2011, we probably won’t be truly participating, but we can still use the problem definition.

So, if you are interested in participating in this topic, contact us or join in in the discussion or the repository:


Other proposals

Two more proposals were made as project topics:

  1. BioMed: As a computational biology researcher at Ghent University, Kenny Helsens proposed to see if he could come up with some suitable project definition in the area of bioinformatics, maybe genome- or proteome related.
  2. Immo and GIS: Another interesting area for a well-suited project might be the combination of historical data made available by some immo website with GIS related data e.g. from OpenStreetMap. A number of interesting problems can be derived, requiring e.g. predictive models. We’ll be contacting some immo websites on this matter.

As these projects are still in their incubation stage, we haven’t yet created any specific web areas for them. However, these might follow very soon, so keep checking back!

Realtime MapReduce

Daan Gerits has been working on some big data and noSQL projects, and was wondering if anybody has experience with bringing Hadoop and/or MR to the realtime playing field, instead of keeping it strictly for batch processing. The basic difference being that you would be able to feed the data crunching algorithms incrementally or by streaming data into the system and have the algorithms merge these into the already (partially) existing result sets.

During a presentation at the SAI on 7 April 2011, Steven Noels and Wim Van Leuven also pointed out that any big data processing system needs a combination of a batch layer with a speed layer to achieve at least eventual accuracy. The speed layer architectually being the most challenging. However, if we could combine realtime with existing MR algorithms, …

Some suitable technologies and pointers where raised: Yahoo S4, IBM InfoSphere Streams, Datastax Brisk, and Twitter’s Storm. However, no practical experience exists within our community.

Big Data Technology poll

As our meetup group was rather small, we did not redo the technology poll. However, we were wondering if some suitable tool exist to automate the poll via the website or other electronic means, like Google docs. So if you have any good idea in this area, please let us know!

See y’all at the next meetup!

The day after …. and more

So it has been a whlie since we held our first meetup on July 5th, 2011. We had a lively discussion on ideas, wants and won’ts for our young but apparently vibrant community. After some discussion in our group, we prefer to setup our meetups using a rotating schedule over Tuesday, Wednesday and Thursday at an interval of 6-7 weeks.

So, we’ll be calendering our 2nd meetup for Wednesday August 24th, 2011. Keep an eye on our meetup page.

All ideas for  a topic that night are more then welcome!

One day to go …

We have all been anxiously waiting for that special day on which we may kick some life into our community. For those who have no idea what I’m talking about: The Belgian BigData launch event will take place tomorrow in Ghent!

There are a few things we would like to talk about, but most importantly we want your feedback and brilliant idea’s regarding BigData concepts, technologies and the Belgian community.

As you may know, the event will start tomorrow (july 5th) at 6:30 PM in the Atari room of the IBBT Zuiderpoort Office Park (Gaston Crommenlaan, 8 (bus 102), Ghent – map ). The following items are a rough outline of the evening:

  1. Members introduction
  2. Community brainstorm
  3. bbuzz debrief

21 members already confirmed their presence. If you are not one of them and you still want to join the event you can do so on our meetup page. All information about the event can be found there, as well as the list of members which will join us tomorrow.

We are impatiently looking forward to meet you.

See you tomorrow!

Let’s meet!

It is time to meet up in real life! IBBT in Ghent, is so kind to host our very first meeting and you are invited. We have created a meetup-page and would like to ask you to subscribe, if you are interested in joining us for an informal  #bbuzz debrief and community introduction.  The event is free of charge and should be seen as a first contact event of our new little community.

If you are interested in big data and joining a brand new community, put your name on the attendee list!

Hope to see you there!

bbuz – the day after

After 2 intensively immersive days on big data at the Berlin Buzzwords (#bbuzz) conference in Berlin, the crew is back in Belgium again. Those two days were a rollercoaster ride of meeting smart people and listening to great talks on everything big data, NoSQL datastores and scalable search.

There were quite some people present at the event: Andre Kelpe, Wim Van Leuven and Steven Noels (who presented on Lily) with 2 of his colleagues at Outherthought. Of course we weren’t noticeable amongst the crowd of about 450 data geeks: we might have missed some other Belgians out there. So, if you were there or know somebody who was, please step forward and get in touch! We want you!

The conference itself was a great lineup of two keynotes and numerous sessions on three tracks (store, scale and search) by the most knowledgeable people in our specific domain. Check out the agenda for Monday and Tuesday! Slides are posted here as they become available.

There were a few presentations that kept simmering through the hallways. Jonathan Gray‘s exposé on Realtime Big Data at Facebook with Hadoop and HBase was much bespoken because a bit controversial. Remember that Apache Cassandra was developed at and open-sourced by Facebook in 2008.

Also, during the second day keynote, Ted Dunning challenged the Hadoop, and more generally, the Apache community. He postulated that the days as a community are over. Too many stakeholders participate with too many conflicting interests. For the first time in its existence, the Apache Software Foundation  is confronted with such a large scale community. A community that is becoming an ecosystem. And the ASF is not the right body to manage it. A provocative but also challenging thought. But what is the right structure to manage that eco-system? A Linux-like guerilla approach? Or an overly structured standards body? These are some thoughts that I have been discussing with Lars George, but of course without finding an answer. There’s only a sense of future promises. A future that looks difficult but interesting …

Remember if you were there, or not, but you are interested in big data, we want you! Get in touch and join!!!