Varnish, session_linger and dropped connections

Recently I conducted a load test on my beloved low end Ubuntu 8.04 VPS. The setup consists of a mysql 5.1 DB, a Tomcat 6 webapp, openjdk 6 and Varnish 2.1.2. The load generator was issuing HTTP GET requests through a DSL connection which were supposed to create a decent load on Tomcat. To my … Continue reading Varnish, session_linger and dropped connections →

A counterintuitive relation between CPU and memory usage

Continuing my tests on low-end server environments, I recently set up a stress test of a load balanced tomcat webapp. Part of that tests consist in reducing the available memory for the webapp (JVM -Xmx switch) and see how low it could go before negatively affecting performance. It's common knowledge that once available memory runs … Continue reading A counterintuitive relation between CPU and memory usage →

Fixing screen brightness on a Samsung R60 and Ubuntu 10.04

Finally the day came when all the clean installs in the world will not make Vista any faster on my old Samsung R60 (1.5 Ghz Dualcore), so I figured it's time for a Linux distro. Apart from high power consumption (it's a known bug [1]) nearly everything worked as expected, left two things: I wasn't … Continue reading Fixing screen brightness on a Samsung R60 and Ubuntu 10.04 →

When IE does not load images

Recently the need for a custom photo gallery surfaced in one of my GWT pet projects. While such an endeavour seems endless from an artistic point of view, the mechanics behind it - at least for my humble needs - were rather simple: the gallery widget will be given a list of image IDs for … Continue reading When IE does not load images →