Friday, September 23, 2005

Introduction to JBoss Seam

JBoss guys - as I understand mostly Gavin King and Thomas Heute have written an Introduction to JBoss Seam. From a first glance at it this is a real neat document.
It looks like JBoss Seam has a good future to become a de facto standard for webapp development.

The funny part about JBoss Seam is that with it, there will be no more seamless development and integration. Nice marketing trick. Hey, who hat the idea to this name?

Wednesday, September 14, 2005

iPod dropout killer

Lately after the Stuttgart-Lauf, I started again with jogging. I thought that it might be a good idea to have my iPod with me. I had it in my trouser pocket on the backside, as I don't like carrying things in my hand when jogging. After about half an hour, the iPod had some drop-outs which led it into a state where a soft reset was needed or a soft reset did no help and I had to wait until home to plug it into the power supply to do a hard reset.
Since then I bought a sports wrap to attach the iPod to my upper arm. Since I have the sports wrap, I had no more drop-outs on the iPod.
Of course, the iPod shuffle and iPod nano don't need this as they flash based and do not need to access a hard disk to load the songs into memory.

Thursday, September 01, 2005

JBoss rock solid under load

In the last days, I was able to run some syntetical load tests on a Sparc V490 with 4 dual-core cpus, having 16GB or RAM and running Solaris 9. As the target system will be JBoss 3.2.6, we tested against this one.

Tests were conducted with JDK 1.4 and JDK 5.0, having a separate machine firing http requests at the JBoss.

JBoss was rock solid, even when the test app first had an error, not removing stateful session beans, thus passivating thousands of beans.
As expected, garbage collector settings have a huge impact on the overall performance. With bad settings we were only able to saturate two cpus, while with the right ones we kept all 8 cores busy.

Also JDK 5.0 performs a lot better than JDK 1.4 (which was expected anyway).
We also found out, that top on solaris has a bug, only displaying at most 999 lwp, even if a process has much more of them.

For someone usually only having one to two cpus at his hands, this was a nice occasion to play with a "big iron" (yeah, I know that this still is a small box).