Favorite recent for SaaS

• SaaS vs. Software: SaaS has a built-in usage feedback loop
• On-Premise vs. SaaS and Cloud-Computing solutions
• SaaS Strategy: What the top brass wants to know
• The Enterprise App Store and Self-Service IT: How SOA, SaaS and Mashups Will Thrive

SOA special day

Today is a really special day for me. I’ve passed (with honors) in the first soa exam S90.01. Also I was surprised with a perl over the internet: the book SOA with .NET and Windows Azure: Realizing Service-Orientation with the Microsoft Platform.

I really feel sorry for those who learned WCF wihtout any take time to understand service-orientation fundamentals and principles. But, still have time to try to recover from such mistake. And these books shows a brifly introduction to some service-orientation concepts while demonstrating how to implement in Microsoft Plataform – WCF, Azure, SQL Server and BizTalk.

Safari Books publishers offer a service which you can interact with book’s authors as they write their book, you can try it. As Soabooks.com always postpone their book’s release to another Q(something of year something too) and never deliver new books, you may want to delight yourself by using Safari service’s “Rough Cuts“. What incredible!

I have not seen best WCF book. Actually, books with tecnology documentation only is waste of time, if want to be ahead in IT Industry. SOA with .NET and Windows Azure is the best WCF source of information. It really does a good job. Authors, congratulation for such nice work. I waiting for it.

SOA and Risk Management

A very nice link about contrasting views on the relationship between SOA and risk

http://www.soaguru.com/soa-and-risk-management

Contract-First Approach Still

There’s one thing I want to mention about my last post on contract-first methodology.
In service inventory, Entity Services layers might be generated by a tool, as opposite to the goodness about write the contract by hand.

Last century, when I other web developers endeavors were working with JavaScript/HTML, we could notice how different code was depending on the handcraft’s origins (notepad or other advanced tools for that time).

Companies already have their system and database models. Moving to SOA is a strategy that could take years . Advantage from tools could be taken if we do generate contract from database tables and thereafter, and also generate services and users interfaces from those very contracts. For all those legacy work, this approach should be nice.

What a hell, man? You may ask now.

One thing which intrigues me is runtime coupling between objects. When using WCF to generate contracts for your services and the visual studio solution might have many services within. Of course you may want to reuse some comportment instead of creating them when you are build service compositions. But, if you need to change those objects (or contract), you will realize a horrible buildtime coupling problems and you may need to upgrade all consumer contracts instead of just release another WSDL contract version at you service.

Again, balance the situation is good. SOA has to be intrinsically with the financial economies. If the company is already established in its industry and need more power, SOA is a mandatory tool. If the company still about to grow, SOA is an option that the advantages and slows might incommodities.

Bouncing puppies for WSDL Contract First Approach

Ohh.. Bloody hell!! Contract First Approach or Not?  What about the common sense of proved advantages and what to do when we have infinite services to create and loads of business domains to take care of?

Lets take Tomas Erls books’s approach into account by imagining the following scenario:

- 50 Business Entity (which would compose something like 35 Entity Services)
- 5 Business Process (which would compose something like 10 Task Services and 10 Utility Services.

Have a look here and here and reflect about the scenario I’ve shown. To much code indeed and space for human mistakes. What about the work to convert WSDL into client and server code as shown here. That’s not simple, isn’t it?

Migration to a SOA ecosystem needs some sort Model Driven development and deal with contract-to-technology coupling if we want to things more quickly. We still need model and plan accordingly but we shouldn’t take so much time to write one or two service compositions. I know about SOA vendor option but in the first moment can be a good idea to trust a technology plataform.

Thus, I believe:

If we are within the boundaries of the enterprise or/and the services are not requested by many consumers, we may not need the contract-first approach but still need to care about governance.
if we need to communicate outside the boundaries of the enterprise, we need to do Contract-First approach so we can make sure we ‘re experience the partner experience in communication with us.

Thereafter, go with velocity!!