Inductive Bias

Since several months at neofonie we have a talk given by external or internal developers on various subjects each Tuesday. Usually these presentations are a nice way to get an overview of new emerging technologies, to get an overview of current conference topics or to gain insight into interesting internal projects.

This week we had Apache Tomcat Committer and PMC Peter Rossbach here at neofonie to talk about the Tomcat architecture and Tomcat clustering solutions. He gave two pretty in-depth presentations on the Tomcat internals, Tomcat optimization and extension points.

Some points that were especially interesting to me: The project started out in the late nineties, initiated by a bunch of developers who just wanted to see what it takes to write a web application container and that fullfills the spec. The goal basically was a reference implementation. Soon enough however users defined the resulting code as production ready and used it.

There are a few caveats from this history that are still visible. One is the lack of tests in the codebase. Sure, each release is tested agains the Sun TCK - but these tests cannot be opened to the general public. So if you as a developer make extensions or modifications to the code base there is no easy way of knowing whether you broke something or not.

For me as a developer it was interesting to see really how complex it quickly gets to cluster tomcat deployments and make them failure resistant. Some tools mentioned that help automatic with easier deployment are Puppet and FAI. One issue however that is still on the developer’s agenda is Tomcat monitoring.

To summarize: The conference room was packed with developers expecting two very interesting talks. Thanks to Peter Rossbach for coming to neofonie and explaining more on the internals of the Tomcat software, the project and the community behind.

Software Foundation Event, Free Software, Software Foundation, tomcat

Title: Cloud Camp Berlin
Link out: Click here
Date: 2009-04-30

*Camp, General Event, Free Software

This year for the 11th time the “Linux Tage” were organized at the university of Chemnitz. Each year in March this means two days devoted to the topic of open and free software. It means an event that is very well organized by a pretty professional team of volunteers.

For the third time the FSFE had its booth at the event - this time run by Rainer Kersten, Uwe Zemisch and me. Recurring questions at the booth were

• “What the hack is FSFE and in which ways do you actually support free software?”
• “I am already fellow, you keep telling me there are these great fellowship meetups. Do you know whether there is one near my town? How do these events start? How are they organized?”

It was interesting to see that FSFE is one of the few organizations that try to fill the gap between those writing open source software and those actually making decisions that are relevant to the developers but know nothing of writing software whatsoever.

Besides running the booth there was some time left for a few talks. I decided to go to the OpenMP talk. The idea is to develop a highlevel API for marking code passages for parallel execution. It is not designed for parallel programming on clusters but on multi core machines. Somewhat related to the Java concurrency package but far more high level.

The second talk I went to was on personal data protection laws in Germany. One funny piece of information: Even the ministry of justice was sued sucessfully for storing to much information on the visitors of its webpage.

Last talk I went to was on Google Android. To me it looks like a nice mix of completly open source (like Open Moko) and completely closed source. If you need a phone you can use for making phone calls but still want to play with it and be root on the phone (399$ for the dev phone, sim unlocked, only available for registered developers, registration is 25,-$), Android G1 propably is the way to go. The phone is highly integrated with Google applications. The assumption when building it seems to have been, that people are online all the time with that phone.

For coding: Only a Java API is available, no C or C++. SDK is available for Lin/Mac/Win. The emulator does work, only thing it does not reflect is the real speed of the device itself. Each app gets its own VM, Dalvik supports process memory sharing that makes that less expensive. In case of memory shortage apps are killed in order of user impact (empty/precreated, background, service (mp3 player), visible apps, foreground apps). Idea is to kill those apps that are least visible to the user. The programmer needs to take care that apps constantly store state so restarting them gets them up in the same state they were in when killed.

More information online: http://www.htc.com; adoid.git.kernel.org;

All in all: Really nice weekend. Looking forwared to return next year.

Free Software, General Event, Free Software, FSFE

Title: FSFE Meetup Berlin
Location: newthinking store
Start Time: 19:00
Date: 2009-03-12

The FSFE Berlin group is going to meet next Thursday. Topics to discuss at the next Get Together are

• Document Freedom Day activities.
• This year is the year of elections in Germany. How do we get the topic of Free Software into the discussion?

Feel free to visit the wiki, drop by and take part in the discussions. After the meetup we will go to some restaurant close by for food and drinks.

General Event, Free Software