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

168 Chapter 9 Testing from SOA to the Clouds
built for specific purposes, and many more are hosted by cloud computing
providers.
Moving up the stack, we find composite services, or services made up of
other services, and all services leveraged by the business process or process
layer, which provides the agile nature of an SOA using cloud computing, since
we can create and change solutions using a configuration metaphor, as we discussed
in Chapter 1.
When testing services, keep the following in mind:
Services are not complete applications or systems and must be tested as such.
They are a small part of an application. However, they are not subsystems;
they are small parts of subsystems as well. They must be tested with a high
degree of independence, meaning that the services are able to properly
function both by themselves and as part of a cohesive system. Services are
analogous to traditional application functions in terms of design and how
they are leveraged to form solutions, fine- or coarse-grained.
The best approach to testing services is to list the use cases for those services.
Then we can design testing approaches for that service, including testing
harnesses, or the use of SOA testing tools that automate testing at the interface
and service levels (see Figure 9.1). We must also consider any services
the service may employ: they must be tested holistically as a single
Automated
Testing Software
Monitoring
Figure 9.1 Automated testing tools allow services to be tested using preprogrammed
scripts and programs that simulate real usage.