Cloud Computing and SOA Convergence in Your Enterprise: A Step ...

Creating the Governance Model 155
policies define how a policy is carried out at the lowest level of granularity.
Following are examples of micro policies:
Only those from Human Resources can leverage Get_Sal_Info services.
No more than one application, service, or process at a time can access
the Update_Customer_Data service.
The Sales_Amount data element can be updated only by the database
administrator, and not by the developers.
The response time from the get_customer_credit service must be less
than 0.0001 seconds.
Micro policies are very specific and typically destined for implementation
within service governance technology that can track and implement
these types of policies.
Design Policies
Returning to Figure 8.1, policies are designed like any other part of the architecture.
The purpose of a policy design is to describe the correct behavior for
the service as well as who is allowed access to the service, what they can do
with it, and how that access is logged. Finally, a policy defines all other applications,
services, processes, and data bound to that service.
While there are design-time governance technologies and approaches, as
we discussed in Chapter 6, for the most part, you will design your policies using
standard office automation technology. However, you will typically implement
your policies by leveraging runtime service governance technology.
You can think of the design component of policies as the process of defining
what the policies will do and for what service. Typically, this means
listing things that are not allowed, or creating rules. Once the policies are
well defined, we implement them using runtime service governance technology,
which is the integrated development environment (IDE) and the platform
we leverage for policy execution (see Figure 8.5).
Implement Policies
You can consider policies as programs, really. And thus they must be designed,
created, tested, and deployed as any program should be. This is the
process of implementing policies, which includes testing and deployment.