The new Telenet Telemeter was released this weekend. Telenet is one of the two greatest Belgian cable providers. The telemeter is a tool where you can view how much data you have uploaded and downloaded. It is also possible to specify if (and when) you want to get an e-mail or a webpage when you have reached for example 80% of the monthly volume that you can download.
This project interfaces with the Telenet backend by using Hessian (we first used Axis, but since both application are written in Java, we decided to switch to Hessian in order to have a performance gain). The switch from Axis to Hessian was simply a matter of switching Spring configuration, which again indicates the cleverness of the Spring framework.
The application displays some charts. After a rather negative experience with jFreeChart and CeWolf, we decided to use FusionCharts, a flash application which uses XML to render the graphs. This choice has a lot of benefits:
- The XML is very easy to understand and generate
- Load is moved from the server to the client
- It’s easy to switch layout and graph type
- The graph can contain a lot of useful information without using huge html imagemaps
- The graphs can use animation, which give a wow-effect to the end-user
The telemeter now runs very fast (considering what happens behind the scenes) on a WebLogic cluster, but had some initial load problems because of another application that was running on the same server that crashed it.
It is sometimes humorous to read the post on the Telenet user forums, where a lot of people (mostly teenagers have nothing else to do besides downloading movies from newsgroups and complaining about the data limits) report errors which most of the time are just because of their misunderstanding of the application.
I myself am convinced that the data limits are needed so the network stays fast for everyone and isn’t slowed down because some guys want to watch illegal low quality movies. But, of course, this is my own humble feeling about it.