Saturday, October 15, 2005


I decided to move my blog to! So this is kind of a fresh start, since my old posts are going to reside at my own webspace at

At the moment I'm still thinking about how to keep all the links to my old blog online, while using to reach this blog. If someone wants to check out my suggest plug-in at he still should be redirected to If someone wants to check out he should be redirected to Well I'll figure it out, in the mean time you can reach my old blog at

I moved to to escape hosting my own blog software. I hate updating and patching my blog, since it's a tedious job! I hope will save me the trouble.

Wednesday, October 12, 2005

Java performance

The Java™ language is the target of a lot of abuse for performance. And while some of it may well be deserved, a tour of message board and newsgroup postings on the subject shows that there is a great deal of misunderstanding about how a Java Virtual Machine (JVM) actually works. In this month's Java theory and practice, Brian Goetz pokes some holes in the oft-repeated performance myth of slow allocation in JVMs.

rating comment: Very interesting article, giving some insight on how a JVM handles garbage collection and memory allocation. It has been some time since I looked into data structures like heap and stack so this article was a good practise to revise that knowledge.

Saturday, October 8, 2005

Approaches to Performance Testing

Performance testing is a tricky business, and as Matt Maccaux explains, very much dependent on the type of results you want to achieve. Learn more about benchmarking, capacity planning, soak tests, and peak-rest tests.



Saturday, September 17, 2005

BPEL explained

BPEL is an important language for the process-oriented approach to SOA. Because BPEL has been designed specifically for definition of business processes it provides good support for various specifics of business processes such as support for long running transactions, compensation, event management, correlation, etc. BPEL is well suited for use with the J2EE platform and many BPEL servers build on top of J2EE. With ideas of combing BPEL and Java (BPELJ), and WSIF, the usability of BPEL is even increasing. We should also look at the emerging JBI (Java Business Integration) specification aka JSR 208 which will give business integration and BPEL an even better documented position in the Java platform.

rating comment: I've read a couple of articles about BEPEL, and I must say that this one is the best so far. It answered all my questions which emerged while reading the other articles. Although I don't have any practical experience with BEPEL whatsoever, I think it's an important approach in order to build a SOA.

Wednesday, September 14, 2005;

Google hat eine spezielle Suche für Blog-Inhalte gestartet, um das Finden von Blogs im Internet zu vereinfachen. Suchergebnislisten stehen als RSS- und Atom-Feeds bereit, um sich über Neueinträge zu bestimmten Themen auf dem Laufenden zu halten. Wie bei Google üblich befindet sich die Blog-Suche derzeit noch im Beta-Test.

Monday, September 12, 2005

Unit Testing Rules

A test is not a unit test if:

  • It talks to the database It communicates across the network
  • It touches the file system
  • It can't run at the same time as any of your other unit tests
  • You have to do special things to your environment (such as editing config files) to run it. 

Tests that do these things aren't bad. Often they are worth writing, and they can be written in a unit test harness. However, it is important to be able to separate them from true unit tests so that we can keep a set of tests that we can run fast whenever we make our changes.

I agree in that unit tests should be completely independent of their environment. I also agree in that you should rather use mock objects instead of e.g. a database. What I don't agree on is that it's supposed to be a bad thing to change your environment to be able to run a test. Let's say you run unit tests for a persistence component, why is it a bad thing to change the persistence implementation, so that mock objects are being used, before running the tests? If you are using  an automated tool, it can be done transparently, without any manual changes needed.

Friday, September 9, 2005

Programmers' personality

.. something that I've noticed when I interact with other programmers. It should come as no surprise that the personality profile for programmers is not the same as that of the population at large. In fact, I feel that when I arrive in an airport for a software conference, I can usually just "tell" whether another person I see walking by is there for the conference or not. We're a weird bunch..

I am glad, that I am not the only one feeling this way ;-)