January 2004

This weekend we'll be in Center Parcs, a holiday parc where I and a number of friends go every year.

It's in Zandvoort, a sea-side village close to Haarlem.

A nice game for the Friday afternoon: Smack the Pingu.

My highest score so far is 492.2; rumor has it that higher scores are possible.

This game is not recommended for penguin-fans.

We are now officially P3P compliant:

> Thank you for making your site P3P-compatible.
> I added your site to the list.

Daniël and I agreed last night that it's really inconvenient that the shops in the Netherlands close so early. In the States, Hungary, Bulgaria... everywhere the shops are open till after 18:00 o'clock, so people who work during the week are also able to go shopping.

Alas... not in Holland. The only exception is Thursday evening (in Haarlem) when many shops stay open till 21:00 o'clock. So it's always more lively in the city and I like Thursday evenings. Tonight I had to do the things I didn't have time for during the week. Somehow there's a lot of paperwork to arrange this week and I went to the municipality to get some official paper. That went pretty quick; the people at the civil service there are very friendly.

On of the things I have to arrange is my own fault. When I came back from Washington in October I forgot to turn in my "I94-W" form, a small sheet that had been stapled in my passport when I entered the States. Now I have to send it to an office in the States, along with proofs that I did return to the Netherlands. So I'll send my boarding pass from the return flight, a copy of my passport with the stamps that prove I was in Bulgaria, and some papers of my work.

I have been working for a long time on a project for Vialis. Vialis produces and sells parking machines in the Netherlands, and Chess has been developing a new type of parking machine with them (smarter, quicker, more payment methods).

About a week ago five parking machines of their new type have been placed in Nijmegen, and are currently being used.

Personally I've been involved in the back-end part of the system: the computer that registers and detects what's going on with the parking machines.

There has been quite some publicity about the new system; today we saw that there was an article in the Intermediar, a Dutch technology magazine.

For my work I came across a new Internet standard: the Platform for Privacy Preferences, or P3P. This allows a website to inform its customers of its privacy policy: how does the website deal with the personal data of its users.

An important aspect of the standard is that the format is both human- and machine-readable. Internet Explorer 6.0 knows how to read this information for example (see the screenshot below). You can tell Internet Explorer what your preferences are, for example that you never want to give your e-mail address to sites that sell e-mail addresses to third parties. Your browser will then warn you if you enter such a website.

I've created a policy for Guus Bosman.nl, to see how it works. My privacy policy is pretty simple: I don't sell, share or give away information on my visitors to other people. However, the website uses "cookies", to keep track of logged in users and to remember your username. <

All this you can read in my Privacy Statement.

I liked the game Diplomacy that we played today a lot. I'm a big fan of this type of games: the emphasis is on negotiations, and there is (hardly) any luck involved.

We had a great day, which is of course the most important, but I'm also quite satisfied with the end result. I share a third position with Evert (out of seven players). The results:

Quite a difference with yesterday, when I woke up nice and late: today the alarm went at 7:00 o'clock.

Today I'm going to Jerry's, where we'll play "Diplomacy", a game. I've never played it before, it's supposed to be really good.

When I came into our livingroom it smelly really nice of the hyacinth my mam gave me a week ago.

Yesterday at the end of the afternoon Mark and I did an experiment with my website.

We were looking at a program that can be used to measure the performance of a website: how many visitors per minute can it reasonably handle? We need such tools for our work, and we did a quick experiment with a new program that Mark found.

I don't know exactly how many visitors my website usually has. I should really find that out once! A very rough estimate (for last Tuesday) indicates that every two minutes a page of our combined websites gets visited.

Background
The website you are reading is running on a new PC, and that computer doesn't do a lot more than handling the website. That means that in theory it could deal with quite a lot of visitors at the same time.

However, the connection of my computer to the internet is a major bottleneck. It's an ADSL connection with a maximum upstream of about 380 Kbit/s. If there are a few people on my website this is definitely fast enough. More than, say, ten visitors per minute would be a problem: the website would become very slow.

The experiment
The program we used yesterday is called JMeter. It behaves exactly as a user visiting a website: the website doesn't see the difference between a real visitor and JMeter. Because it's automatic, you can configure it to behave as a group of visitors too; which is of course the powerful aspect of such programs. We configured the tool such that 40 people would visit my site every minute. Half of them would see the whole website (including pictures); the other half without pictures. We then run the test for 15 minutes.

The result
The main result: when 40 people per minute are visiting the site, it will take around half a minute for a new visitor before he sees the frontpage of the site, and another minute before all the images and pictures will have been downloaded. That's pretty good! Of course for a professional website that would be quite slow, but for my self-made and self-managed hosting solution it's quite reasonable.

We also re-run the tests with an even bigger amount of visitors. If 400 visitors per minute visit the site, many of them will be blocked: the computer simply refuses to serve them. This type of test is called stress tests: seeing if the server would crash under heavy pressure. With 100 visitors per minute the site gets very slow of course: an average of more than one minute per page without images, and much longer if images are included. But the important result is that the computer didn't crash, and kept functioning.