In a previous blog I discussed the speed of the Spray-can web-server and mentioned some measurements I did. My co-worker Age Mooij, committer on the Spray project, pointed me at ‘weighttp’ (see weighttp at github) a tool for benchmarking web servers. Cool! Of course I now had to do more experiments and so I did. I found out Spray-can is way too slow for my purposes and here’s why.
Read more →

Everybody has encountered many awful error messages in his career. Text messages like “Server error”, “Exception occurred”, and the like or messages in a GUI box just containing some error number (if you are lucky, we have seen empty boxes as well, right?). Clearly, this not the way to present error messages to users. So let us take a look at some properties of good error messages. I present two of those good properties here: the “finger” and the “tell”.
Read more →

I am addicted to a problem: handling unknown peak load on the net. Part of the solution I have in mind involves, of course, a fast web-server. One of the fastest around is Spray-can (see https://github.com/spray/spray-can) and I really like the thing for several reasons I won’t explain here. Anyway, I’m sure you can guess my very first question by now:

How fast is Spray-can really?

Read more →

A number of my colleagues and myself recently decided to share our knowledge regarding “performance” on this medium. You are now reading the first blog in a series in which I present a test-driven approach to ensuring proper performance when we deliver our project.

Test driven

First of all note that “test-driven” is (or should be 😉 common in the java coding world. It is, however, applied to the unit-test level only: one writes a unit test that shows a particular feature is not (properly) implemented yet. The test result is “red”. Then one writes the code that “fixes” the test, so now the test succeeds and shows “green”. Finally, one looks at the code and “refactors” the code to ensure aspects like maintainability and readability are met. This software development approach is known as “test driven development” and is sometimes also referred to as “red-green-refactor”.Read more →

Last week I enjoyed to opportunity to speak at the Agile2010 conference in Orlando, Florida. Of course, I also attended many of the other sessions as well. The conference has in my view an excellent atmosphere. Where I expected to find lots of consultants in their typical formal style of dressing I found 1400 people mostly dressed in T-shirt, jeans and sneakers instead. This must be the result of the Agile movement itself where people are first class citizens right?

The portfolio of Agile2010 contains ‘hardcore technical’ sessions like tutorials in Clojure coding, real ‘softcore’ sessions like “Behavior Driven Development for Life” which advocated using Neural Linguistic Programming techniques straight from psychology and also sessions around themes like Leadership and Coaching. Don’t worry, the conference organizing committee splits these nicely up in ‘Themes’ and ‘Stages’ so even if you only look at the program by a glance, you’ll hardly ever end up in an unwanted session.

This is what I picked up from the conference in summary (you’ll find all the details below):

• Conference focus (or lack thereof)
• “Religious wars” between Scrum, Kanban, Xp, Lean, …
• Agile adoption in organizations worldwide
• “Value points” (compare to “Complexity points”)
• “Switch”
• Company improvement backlog

Next I’ll elaborate a bit about my own experience as a speaker. The combination of what I picked up and my speaker experience will give you a good basis to decide if you want to put next year’s edition (Salt Lake City August 7-13, 2011) in your agenda or not be it as an attendee or as a speaker. Enjoy!

Read more →