Today I attended a great session of Arvindra Sehmi and Beat Schwegler. First Arvindra talked about the “new” way of modelling connected systems. He explained there is a need for a “Service Oriented Architecture Model” (SOAD)  that sits between the business model and the technical model. While the business model is used to describe the needed capabilities (the “what” part) the SOAD model is al about modelling the contract of the service. At the end we have the Technical model that covers the technical details, like service interface, service implementation, etc. Of course the story covered a lot more details than the above description and it sounded pretty good.

The second part of the session was covered by Beat. He talked about the technical model. Currently he is working together with Cristhian Weyer and Maarten Mullender on a series of articles (first one can be found here) that will provide us with a set of recommendation for designing and implementing connected system (services). In this session Beat showed us that he is already working on the actual implementation of the recommendations. He showed us a Software Factory that is suports building services (by using the GAT). Pretty cool stuff!!!

From what you could see from the demo this series of articles (and implementation) will really show you some of the best practices for building these kinds of systems. Beat defined 8 steps that you have to do to design a service:

1. Design the data
2. Create the data classes
3. Design the messages
4. Design the interfaces
5. Create the transport interfaces (for example web services)
6. Create the adapters
7. Implement the internals
8. Connect the internals to the adapters

The artifacts of the above steps all formed a separate Visual Studio project within 1 solution.

I will not cover all of the above steps but some of the things were pretty interesting:

Within the first step (design the data) we create the XSD schema. This is actually the “data on the wire”. Based on these schemas the data classes are created by using for example XSD.exe. This of course is nothing new, but what we see most of the time now is that the product of step 1 is referred to as the messages. Beat actually showed us that in step 3 we create the actual message class that has a public field (result of step 2) which is actually the message payload. This messages class uses some techniques that I wrote about before to support for versioning and flexibility.

Another interesting thing is that in the “technical model”, when talking about the “service interface” we actually mean the interface definition (public interface IOrderService {}). Besides this the service has some “transport interfaces”, these are the actual implementations of the interface for a specific transport type (web service, Enterprise Service, etc.). Maybe nothing new here but is a good thing that is “written down” as a piece of guidance.

The last thing that I will write about is the introduction of “adapters”. These are actually a “layer” between the service interface (transport) and service internals. By using this technique the service implementation “knows” nothing about the actual message which makes it easier to change the message without breaking the service implementation. Of course in that case the adapter needs to be changed.

All of the artifacts that were created in the above 8 steps were supported by the “Software Factory”. Although it was very early work that Beat was showing it looked really cool, so makes sure to follow the series of articles!

While Tech-ed Europe is on its way it becomes clear to me that a lot of people are currently re-thinking how to implement their architectural requirements. A lot of people that I spoke are (of course) evaluating Visual Studio 2005 Beta 2, Indigo Beta 1 and WSE 3.0 CTP. Some of them (like me) are currently using some sort of a framework or toolset to support their architectural and service oriented needs.

During the talks I had with some people one of the issues that cam up was:  do we need another framework on top of .NET 2.0, Indigo and WS-*? And after that: Is the guidance that we are using now (for the current technology) still valid when all the new stuff is available? And if not, what do we need and when! In my opinion all interesting issues that sooner or later become very valid questions for a lot of us.

Some of the people I spoke, planned to simply migrate their current framework to .NET 2.0 when that is available. This wouldn’t be my preferred strategy. I think there is a relatively big change that simply migrating existing stuff doesn’t use the full power of the new technology. On the other hand, if it takes very little effort to migrate it can be a valid option.

Others thought that simply wait for Indigo to ship is the best option. In the meantime try to decide what you need (framework, guidance, etc.) and try to get that ready as soon as possible. For new systems in the timeframe between .NET 2.0 arrival and Indigo, simply use .NET 2.0 and if needed use WSE 3.0 to solve the WS-* issues.

In my current set of frameworks, guidance, etc. there is special attention for “separating the cross cutting concerns from the actual business logic” and separating the service interface from the service implementation. This is enforced by using a framework. I’ am still thinking how to solve these issues in the new (.NET 2.0, Indigo) world. For separating the service interface from the service implementation I think you don’t really need the help of a framework. This is just a pattern that you can apply.

A little different might be solving the “separating the cross cutting concerns from the business logic issue”. I have some ideas about this but I’ am not sure yet. Unfortunately I haven’t met any people here at Tech-Ed that have some ideas about this, but I’ am sure they must be around here somewhere. Have any ideas about this and like to have a discussion? Let me know!!

In his session Gianpaolo Carraro discussed the so called five pillars of connected systems. Up to now, when talking about connected systems and service orientation most of the discussion is about how to design services, the four tenets,  best practises, etc. Of course these issues are essential when it comes to connected systems but there are other issues that comes in play when thinking of connected systems. This is where the “five pillars of connected systems” comes in.

The “messaging” pillar is the most fundamental and covers the connectivity possibilities of systems in a standardized way. This is actually the pillars that is discussed over and over already (and will definitely need some more discussion in the coming period).

The other pillars that can be identified are:

·         Identity and Access

·         Data

·         Interaction

·         Workflow

The thing that Gianpaolo tried to explain is that all connected systems that we will build in the future need (to some extend) attention on all of the five pillars.

After discussing the pillars briefly, he also presented his “6 rules for success when building connected systems”.  5 of the rules each apply to one of the 5 pillars and 1 rule just concerns some generic issues not related to any of the pillars in particular. It was actually this one (generic) rule that makes sense to me.

This rule is about “accommodate and anticipate for change”. Sooner or later the system you are building will change, so it’s best to design for that. Some of the techniques he mentioned for that is; make use of abstract factories, provider model, pipeline architecture, separation of concerns and inception points.

I had a little more difficulty with the other 5 rules for success so I will not quote them here. To me they didn’t seem to be “rules” but looked more like summing up some attention points. I think some more details are needed in this area to become real rules.

At the end of the presentation it became clear that all of the 5 pillars will get some extra attention in the near future and the so called rules will be supported by (new) features of some of the Microsoft tools or technologies.

More information about the 5 pillars of connected systems can be found on the blog of Gianpaolo. Not everything is there yet, but according to his blog will arrive soon!

Update: changed the name of the “ intergration pillar”  into “ interaction pillar”. These postings are written during the Tech Ed talks, not a lot of time to validate the content. Thanks Carlo for commenting on this!

One of the sessions that I attended today at Tech-Ed Europe is “Building and using Software Factories” with Steve Cook and Annie Matthewman.

I have been reading quite some stuff about Software Factories lately. I even started the book called “Software Factories” but haven’t finished it yet. Although there is quite some information available it kind of bothered me that most of it is purely theoretical, I haven’t seen any real implementation of a Software Factory yet (until now).

Steve first gave some basic information about Software Factories. One of the, maybe obvious, things he stated was that is it only useful to build a Software Factory if you build similar systems every time. If that is the case, the next thing you have to define is a “package” of reusable knowledge that eventually can form the Software Factory. So, in order to be able to build a Software Factory you first need to know what is available and how it can be reused.

The reusable items can vary from a piece of documentation, an architecture baseline, code snippets, wizards, etc.

Summarized, a Software Factory can be described as:

·         (customizable) structured collection of assets.

·         Software Schema that defines the context for the assets.

·         Explains people what to do.

·         Helps people do it.

One of the goals for Software Factories is: easy things should easy and difficult things should be possible.

The second part of the session covered a demo of a real implemented Software Factory. The Software Factory provided guidance for building a “wizard like” windows application communicating with web services.

To support building Software Factories, there are actually two new “technologies/toolkits”. One of them concerns Domain Specific Languages (DSL) and helps building DSL end the appropriate DSL designers. The other toolkit is the Guidance Automation Toolkit (GAT).

For the Software Factory that was demonstrated Steve and Annie actually build a “new” DSL for this problem domain and an appropriate designer for the new DSL. Building this wasn’t covered in this session, but will be covered in another session.

The GAT is a relatively new toolkit that is downloadable from the Microsoft website. The GAT can be best described of a Software Factory for building Software Factories.

From what I saw in the demo one of the pieces of GAT is  a (very) big XML file that describes the activities, actions and their contexts that together form the  (part of) Software Factory. When a Software Factory is build by using the GAT the end result all integrates very nice with Visual Studio.NET helping the developer building the piece of software that is supported by the Software Factory.

I haven’t actually spent time on evaluating the GAT yet but the demo looked pretty cool so I think I will give it a try soon.

This is my schedule for Tech-Ed Europe 2005. Looking forward to some (in my opinion) very interesting sessions and speakers. The sessions are a mix of the “connected systems“  and “architecture“ track. For most of the timeslots I choose an alternative session, just in case there are no seats left in the room when I arrive.

 If you happen to be in the same sessions, say hello, I’ am the one carrying a Tech-Ed bag J

Because I was assigned to project it wasn’t sure if I could make it to Tech Ed 2005 Europe. Luckily, we found a replacement for me at the project J. So I will be there!

Interested in more in-depth details about the implementation of the WS-I Basic security profile application? 

Go read the blog of Hernan de Lahitte who was member of the dev team. I a series of posts he will share his experiences in building this sample and talk about the issues that came up.

Currently Microsoft is working on a sample application that is compliant with the WS-I Basic Security Profile (BSP). This sample application shows you how to build secure web services using WSE. Besides this, the sample also demonstrates interoperability issues and gives some guidance on how to design services that can evolve technology changes by separating the business logic from the transport.

The sample is a “preview release” because the BSP specs don’t have the final status yet. The preview is built using Visual Studio 2003 and WSE 2.0. The final release (which will be available after the BSP specs are final) will be implemented with Visual Studio 2005 and WSE 3.0.

I was one of the lucky ones (J) participating in the reviewing team. So, I had the change to look at the code in an early stage and provide some feedback. I think that this sample is definitely worthwhile spending some time on for anyone interested in web service security and interoperability.

 The sample application will be available somewhere in the coming weeks. Today there is already a webcast available from the Patterns and Practises live site (direct link WS-I BSP webcast) for download. Go check it out!

Currently, one of my colleagues is working on a small assignment to investigate the possibilities of Microsoft Information Bridge Framework (IBF) when it comes to exposing web service functionality to end users. The main goal of this investigation is to determine if IBF is able to communicate with the web services that apply to our internally used reference architecture.

Personally I am not very impressed by IBF yet, but that’s probably because I know very little about this tool. What I do know is that Microsoft is positioning this tool as a key player in its “information worker” marketing strategy so it must be good! For me this tool is just another way to make sure the end user (or should I say Information Worker) continues using the Microsoft Office suite which is probably one of the most important products for Microsoft’s profit. Another thing I know is that many people (especially managersJ) see a lot of opportunities for this tool so we decided to give IBF a fair change.

Therefore my colleague was asked to test if IBF is capable in communicating with “secure” web services. In our case this means that IBF has to communicate with web services that use SOAP headers to support sending “user token” information. After some investigation it turned out that IBF cannot handle SOAP headers (or at least not populate the headers in a “flexible” way). Because I found this very hard to believe I did a quick search on the internet and all found was the capability of IBF to handle “transport layer” security. I noticed that there is very little information available on the internet related to IBF and security. In my opinion using SOAP headers is kind of straight forward when it comes to web services, but I might be wrong.

Is it true that IBF doesn’t support SOAP headers? If so, will this be supported in a next release? If not, IBF is definitely no option for us (at this moment).

If there is anybody out there that can point me to some more information about this, please let me know!