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

124 Chapter 6 Working from Your Services to the Clouds
The directory must be the master directory for the entire architecture spanning
on-premise and the clouds, which eventually becomes the registry.
In more sophisticated cloud computing solutions, the services directory is
becoming the axis mundi, able to access both the source and target systems in
order to discover necessary information (such as metadata and available business
processes). Engaged in this “autodiscovery,” the SOA solution can populate
the directory with this or any other information that may be required.
Ultimately, the services directory will become the enterprise metadata repository,
able to track all systems, services, and information, on-premise or on the
cloud-delivered platforms.
The value of a services directory should be clear. With the directory as a
common reference point for all connected processes, services, and databases,
integrating data and services is straightforward. The services directory can
also track the rules that the architect and developer apply within the SOA
problem domain.
Consider Service Governance
One of the things that is often forgotten when looking at SOA using cloud computing
is the notion of services governance, which is covered more extensively
in Chapter 8, “Bringing Governance to the Clouds.” From SOA governance, service
governance is basically the same concept, or the ability to track, manage,
and control the use of services that span on-premise and cloud-based systems.
There are two types of service governance: design time and runtime.
Design time service governance, as the name implies, typically provides an
integrated registry/repository that attempts to manage a service from its
design to its deployment, but typically not during runtime execution of the
services, albeit some do.
Key components of design time service governance include
A registry and/or repository for tracking service design, management,
policy, security, and testing artifacts
Design tools, including service modeling, dependency tracking, policy
creation and management, and other tools that assist in the design of
services