Monday Dec 10, 2012

Mastering snow and Java development at jDays in Gothenburg

Last weekend, I took the train from Stockholm to Gothenburg to attend and present at the new Java developer conference jDays. It was professionally arranged in the Swedish exhibition hall close to the amusement park Liseberg and we got a great deal out of the top-level presenters and hallway discussions.

Understanding and Improving Your Java Process

Our main purpose was to spread information on JVM and our monitoring tools for Java processes, so I held a crash course in the most important terms and concepts if you want to affect the performance of your Java process. From the beginning - the JVM specification to interpretation of heap usage graphs. For correct analysis, you also need to understand something about process memory - you need space for the Java heap (-Xms for initial size and -Xmx for max heap size), but the process memory also contain the thread stacks (to a size of -Xss), JVM internal data structures used for keeping track of Java objects on the heap, method compilation/optimization, native libraries, etc. If you get long pause times, make sure to monitor your application, see the allocation rate and frequency of pause times.

My colleague Klara Ward then held a presentation on the Java Mission Control product, the profiling and diagnostics tools suite for HotSpot, coming soon. The room was packed and very appreciated, Klara demonstrated four different scenarios, e.g. how to diagnose and fix latencies due to lock contention for logging.

My German colleague, OpenJDK ambassador Dalibor Topic travelled to Sweden to do the second keynote on "Make the Future Java". He let us in on the coming features and roadmaps of Java, now delivering major versions on a two-year schedule (Java 7 2011, Java 8 2013, etc). Also letting us in on where to download early versions of 8, to report problems early on.

Software Development in teams

Being a scout leader, I'm drilled in different team building and workshop techniques, creating strong groups - of course, I had to attend Henrik Berglund's session on building successful teams. He spoke about the importance of clear goals, autonomy and agreed processes. Thomas Sundberg ended the conference by doing live remote pair programming with Alex in Rumania and a concrete tips for people wanting to try it out (for local collaboration, remember to wash and change clothes).

Memory Master Keynote

The conference keynote was delivered by the Swedish memory master Mattias Ribbing, showing off by remembering the order of a deck of cards he'd seen once. He made it interactive by forcing the audience to learn a memory mastering technique of remembering ten ordered things by heart, asking us to shout out the order backwards and we made it! I desperately need this - bought the book, will get back on the subject.

Continuous Delivery

The most impressive presenter was Axel Fontaine on Continuous Delivery. Very well prepared slides with key images of his message and moved about the stage like a rock star. The topic is of course highly interesting, how to create an infrastructure enabling immediate feedback to developers and ability to release your product several times per day. Tomek Kaczanowski delivered a funny and useful presentation on good and bad tests, providing comic relief with poorly written tests and the useful rules of thumb how to rewrite them.

To conclude, we had a great time and hope to see you at jDays next year :)

Wednesday Nov 28, 2012

Creative, busy Devoxx week

I got back from my first visit to the developer conference Devoxx in Antwerp. I can't describe the vibes of the conference, it was a developer amusement park, hackergartens, fact sessions, comic relief provided by Java Posse, James Bond and endless hallway discussions.

All and all - I had a lot of fun, my main mission was to talk about Oracle's main focus for OpenJDK which besides development and bug fixing is making sure the infrastructure is working out for the full community. My focus was not to hang out at night club the Noxx, but that was came included in the package :)

The London Java community leaders Ben Evans and Martijn Verburg are leading discussions in the community to lay out the necessary requirements for the infrastructure for build and test in the open. They called a first meeting at JavaOne gathering 25 people, including people from RedHat, IBM and Oracle. The second meeting at Devoxx included 14 participants and had representatives from Oracle and IBM. I hope we really can find a way to collaborate on this, making sure we deliver an efficient infrastructure for all engineers to contribute to OpenJDK with.

My home in all of this was the BOF rooms and the sessions there meeting the JUG leaders, talking about OpenJDK infrastructure and celebrating the Duchess Duke Award together with the others. The restaurants in the area was slower than I've ever seen, so I missed out on Trisha Gee's brilliant replay of the workshop "The Problem with Women in IT - an Agile Approach" where she masterly leads the audience (a packed room, 50-50 gender distribution) to solve the problem of including more diversity in the developer community. A tough and sometimes sensitive topic where she manages to keep the discussion objective with a focus of improving the matter from a business perspective.

Mattias Karlsson is organizing the Java developer conference Jfokus in Stockholm and was there talking to Andres Almires planning a Hackergarten with a possible inclusion of an OpenJDK bugathon. That would be really cool, especially as the Oracle Stockholm Java development office is just across the water from the Jfokus venue, some of the local JVM engineers will likely attend and assist, even though the bug smashing theme will likely be more starter level build warnings in Swing or langtools than fixing JVM bugs.

I was really happy that I managed to catch a seat for the Java Posse live podcast "the Third Presidential Debate" a lot of nerd humor, a lot of beer, a lot of fun :) The new member Chet had a perfect dead pan delivery and now I just have to listen more to the podcasts! Can't get the most perfect joke out of my head, talking about beer "As my father always said: Better a bottle in front of me than a frontal lobotomy" - hilarious :)

I attended the sessions delivered by my Stockholm office colleagues Marcus Lagergren (on dynamic languages on the jvm, JavaScript in particular) and Joel Borggrén-Franck (Annotations) and was happy to see the packed room and all the questions raised at the end.

There's loads of stuff to write about the event, but just have to pace myself for now. It was a fantastic event, captain Stephan Janssen with crew should be really proud to provide this forum to the developer community!


Been with the Java platform since 2002, mostly JVM. Active as a scout leader with a strong passion for coordinating community efforts. Working current with OpenJDK, making sure developers can contribute efficiently. Tweet me comments! @ceciliaborg The views expressed on this blog are my own and do not necessarily reflect the views of Oracle.


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