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# Monday, 30 December 2002
Trust and Global Service Registries
Monday, 30 December 2002 18:50:08 UTC ( Architecture )

When talking about service oriented architectures we basically talk about three fundamental pieces. There is a service consumer that queries a service registry or a service broker for a set of service providers that meet a set of supplied criteria. The service consumer then selects the preferred service based on a set of preferences, and the required operations are performed on the selected service.

The interesting thing about this is the fact that the industry has launched the vision of a global service registry where one could organize and resolve services using some sort of global taxonomy. Even though this approach might work for the most rudimentary of services what is increasingly interesting is the fact that their visionary samples tend to touch the area of B2B commerce. As most procurement managers know, one of the most important aspects of any supplier selection process is to establish a reliability level. When you find a supplier that satisfies your requirements you set up a trade agreement to ensure that the reliability level is agreed upon and maintained. You establish a trust relationship. The thing is that I fail to see how this is going to work with a global registry of supplier-like services. Where is the negotiation phase that is designed to establish a working business relationship with an implied two-way trust?

My point here is by no means to undermine the importance of a service broker or a service registry when it in fact is a hugely important part of any service oriented architecture. It will play an important role in making your application both pluggable and highly interoperable while effectively enforcing a much needed level of abstraction. But a successful registry has to be filled with a set of pre-approved services from a set of suppliers that the customer has established a healthy business relationship with. Providing such a private registry service makes perfect sense in any B2B architecture. Trying to solve the complexity of a negotiation phase in a machine readable service contract doesn’t.

Even though the industry is starting to address this issue, and somewhat shifted the focus towards local registries, I still see the oversimplified idea of a global registry in both technical writings and vision documents. Hopefully we will all accept that there is a reasonable complexity involved in streamlining current business processes.

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# Friday, 27 December 2002
Developer Lifestyles
Friday, 27 December 2002 18:21:48 UTC ( Security )

Keith Brown (Mr. Windows Security) has written an interesting piece about developer lifestyles in relation to security. Definitely worth a read!

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# Friday, 20 December 2002
Encoding Problems
Friday, 20 December 2002 20:25:07 UTC ( Blog )

I’ve been having some encoding problems with my RSS stream. There seems to have been some disagreement between my RSS generator, my web server, some RSS consumers and UTF-8. Hopefully it’s working better now.

Thanks to my friend Clemens for the heads up!

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# Wednesday, 18 December 2002
XHTML 2.0 Moving Along
Wednesday, 18 December 2002 21:14:33 UTC ( General )

The HTML Working Group has released the third Working Draft for XHTML 2.0!

All we need now is for Visual Studio and Internet Explorer to officially support XHTML versions 1.0 and 1.1 ;)

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Time Zone Headaches
Wednesday, 18 December 2002 20:43:54 UTC ( Architecture )

Globalization has never been an easy aspect of any development project. Lately I’ve been evaluating the requirements needed to serve users from different time zones, and at first sight this appeared to be a fairly manageable task. After all it’s just about storing all your dates in UTC time and then adding or subtracting the time difference to get the users local time. Or so it seemed…

First of all, there is no nice way of retrieving the local time zone from the user’s browser, short of using Passport and forcing the user to share his or hers time zone information. So, the user will have to choose the time zone he or she wants to use, and I guess the time zone support is worth the extra seconds spent during user registration.

Then, I entered the domain of the DST (daylight savings time/ summer time) monster. At first I thought it would be fairly easy to find a standard for this, or that Windows or the .NET framework would be nice enough to provide me with the necessary functionality.

The .NET framework does not, to my knowledge, support the ability to have different time zones attached to different threads, like they have with CultureInfo. But Windows 2000 does have a function that allows me to convert a given UTC date to a specific local time zone, just as long as I supply the time zone information; UTC offset and DST information. And it’s even possible to extract this information for every registered time zone from the Windows Registry. It’s not elegant, but it should work as long as I inserted the time zone conversion in the user interface layer. And I could even write my own .NET TimeZone implementation.

This could have been the end of my problems, but of course it wasn’t. As it turns out DST settings tend to vary between countries, and sometimes between regions within the same country and time zone. And to top it off, it varies from year to year. I’m not talking about fairly deterministic things like the last Sunday in March, but more like the time when Sydney had special DST settings during the Sydney 2000 Olympic Games and the fact that several countries, including Norway, decided to ignore DST for several non-consecutive years. I guess that is why Microsoft decided to releases a time zone editor for Windows. At least I can find comfort in the fact that the European Union has created a DST standard, but it doesn’t help historic dates much though.

So, I guess the only way to handle this problem is to create a time zone for each different combination of DST settings and UTC offsets, and collect all the relevant time zone information in a large table. I was hoping it wouldn’t have to come to that :(

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# Tuesday, 17 December 2002
The Beginning
Tuesday, 17 December 2002 22:35:49 UTC ( Blog )

I just modified my homepage to use XHTML 1.1, and while I was at it; I threw in a primitive web log and a RSS 2.0 feed.

So I guess that would make this my first log entry.

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