With the growing number of implementations in the development community based on the SOA (Services Oriented Architecture) paradigm, I see many different governance mechanisms stated in terms of “must”, “shall”, and “only” when someone has begun an implementation of SOA. In this post, I will discuss some of the observations I have seen in my 8+ years of working in the SOA paradigm and provide some advice on how to better manage one of the stickiest areas of SOA implementation – governance.
SOA Governance is probably the most misunderstood area of a SOA implementation in our organizations or projects. Even the community contributors to Wikipedia struggle to provide a single and concise definition for what SOA governance “is.” There are many academic reasons for this struggle, but the overriding reason for this struggle is that governance is a term that means different things to different levels in an IT organization. To the technical manager, governance is controlling what tools, resources, and processes their development team will utilize. To the developer, governance is controlling how they create a service, how they integrate them with other services, and generally how they should be built. To the architect, governance is about controlling what specific services are built, their interactions, the domain of responsibility they satisfy, and how well they can be reused.
With all of these multiple pulls at a SOA governance process, a person can quickly see why there are so many flavors of governance implementations around the community. With the exercise of outsourcing the development of SOA implementations to remote organizations, the puzzle of governance is even more complicated since motivations such as financial, domain control, and experience-to-cost situations arise. I will not be able to cover all of these complicated issues into a single model everyone can follow in every implementation (hence why this is an issue in the first place), but based on my experiences in the SOA Governance model, I will try to provide some simple recommendations that might make the implementation of governance easier for all of these different types of teams.
Understand SOA Governance’s level of control.
The first mistake an organization can make in implementing SOA Governance is to try to control the lowest level of decisions being made in the implementation of SOA services. For example, defining every development tool that a team should use in the implementation of the service is a recipe for disaster. I am not saying that there should not be guidelines around this tooling – only that there has to be a sense of reasonableness and flexibility to prevent teams from needing to “force” a tool to do something it is not really designed to do well. For example, in a presentation at JUG, an architecture member presented their “Toolset Recommendation for SOA Implementations.” It looked something like this.
It was explained to the room that the developers were advised that if they did not use these (and only these) tools in their service development, that their implementation would not be approved by the governance board and hence not eligible for implementation. I can’t fault them in attempting to resolve a major issue in most development communities: toolset control/toolset domain knowledge. After all, how many times have we all been on a maintenance effort where we find that the previous team used an obscure library that takes us days to figure out how to use (much less find a download or instructions for in the community)? However, while their approach was a valiant attempt towards a resolution to these common issues, I believe that it causes a condition I like to term as “over-control.” In my experiences, any approach that causes over-control will generally cause it to fail.
As an example of a condition of over-control; what if a service implementation contains a requirement to provide session support? In Apache CXF, session support is not supported out of box due thread-safe risks. While this condition can be mitigated through the use of some of the tricks of the trade, a different Service framework may have made this implementation easier to develop successfully. However, in the case above, the SOA Governance “standard” required the use of a single service framework. Therefore, the team is quickly out of compliance with governance for picking a different service framework and either fails to implement or implements potentially buggy workarounds to change to the governance standard.
How do you resolve this conflict? Create a toolset board that contains all of your brightest and most reasonably vocal of senior developers. That board should provide multiple recommended toolset options for each framework area. For example, the board should use their past experiences and combined knowledge to define recommended toolsets including documenting each tool’s “sweet spots” and “limitations.” This information should be readily available to the projects teams as then begin lower level design. However, the most important feature of this process is to allow the projects teams to challenge/add new toolsets to the standard through the board. If that case is accepted, the organization as a whole will benefit from the experiences of its project teams, the governance standards stay current and flexible, and projects teams don’t implement a toolset that has known issues identified by the other projects teams. With this approach the governance document for approved toolsets would look like the below (simplified view).
With these types of toolset control mechanisms implemented in SOA governance, we get the best tools being chosen for each of the areas of our implementations along with growing our organizations and development communities. In the end, we have achieve the needs to each of our organizational areas: the development managers get a list of tools to ensure core competency in their teams, the developers get their flexibility and some experience-based advice, and architecture gets their reuse and standardization.
I read Introducing Regular Expressions by Michael Fitzgerald (O’Reilly Media) to gather deeper insights into the details behind regular expressions. Fitzgerald does not disappoint. The reader should sit back and prepare to drink from the fire hose as Fitzgerald drives through regular expressions in many of their entry level flavors and styles. Introducing Regular Expressions is not for the faint of heart as the reader must navigate lots of regex simulator tools and platforms in order to practice the examples that Fitzgerald fires at the reader without mercy.