Scaling sprite image

If you've always wanted, just like me, a way to scale images used in CSS sprites: there's a way [1]. It essentially comes down to a clever overlaying of a mask on an image: 1. a div with overflow:hidden and of a fixed size 2. an img pointing to the sprite is placed inside the … Continue reading Scaling sprite image →

Pidgin having trouble with MSN certificate – and how to fix

I noticed recently that the Pidgin 2.7.5 messenger [1] had problems connecting to MSN with a certificate error about omega.contacts.msn.com. Fortunately I'm neither the first to have that problem, nor to find a solution [2]. MSN apparently replaced their certificate, which now needs to be updated with Pidgin. 1. point your browser to https://omega.contacts.msn.com/ 2. … Continue reading Pidgin having trouble with MSN certificate – and how to fix →

ID trouble with multiple Hibernate entities on the same table

Just a while ago I ran into a case where Hibernate would auto generate a wrong database schema when two entities were mapped on the same table. The good news: it's my fault and not a bug. The better news: here's an account of how to avoid it. Let's assume a mutable entity A mapped … Continue reading ID trouble with multiple Hibernate entities on the same table →

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 →