This time with little less than 24 hours delay - the usual, by some impatiently expected, summary of the Apache Hadoop Get Together. The meetup took place at Zanox' event campus. The room was well filled with some fourty attendees from various companies, experience with Hadoop ranging from interested beginners to experienced users.
Slides of all presentations:
The first presentation was given by Josh Devins from Nokia in Berlin. He is working closely with the OVI maps team. After giving a general overview of the cluster setup as well as some information on what machines they are running Hadoop on. Currently Hadoop is used mostly to process log data and aggregate information from it. For that task scribe is used for log collection, standard Ganglia and Nagios for monitoring and graphing. When starting to process and aggregate log data the main challenge is a mixture of transforming the logs into some slightly consistant format, cleaning logs from noisy data and in some cases initiating the storage of further information from various services. Nokia is a heavy - and happy - user of Pig though they are looking into Hive for making data accessible to business analysts who usually are more familiar with SQL like languages.
As an example - the results of a few simple jobs on analysing location based searches were shown: Looking at where in the greater Berlin area searches for "Ikea" were issued - at least Ikea Tempelhof and Spandau were easy to make out. On a more serious use case similar information could be used for automatically detecting traffic jams. Currently Nokia is only scratching the surface of all information that could possibly be extracted. So there is quite some interesting work ahead.
In the second presentation Simon Willnauer gave a deep dive introduction to the various stunning performance improvements of Lucene4 - the not yet released, not backwards compatible trunk version of Apache Lucene. For more flexible indexing column stride fields have been integrated. With the introduction of an automaton implementation fuzzy query performance could be improved significantly reducing complexity from n to log n. In addition Simon had a great surprise to share with the audience: He proudly announced that Ted Dunning (you know that guy who is active on nearly every Hadoop mailing list, shares a lot of in-depth theoretical knowledge that is backed by proven practical experience?) and Doug Cutting (founder of Lucene, Hadoop and many other Apache projects) are going to be keynote speakers at Berlin Buzzwords.
In the third presentation Paolo Negri shared some inside as to how Wooga's Ruby on Rails/ MySQL based system was scaled. Disclaimer: Redis did play a major role when upping performance.
Videos will be published as soon as they are processed - thanks again to Cloudera for supporting the event by sponsoring video taping.