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

166 Chapter 9 Testing from SOA to the Clouds
been prevented with adequate testing. We need to take these lessons, hardlearned
by others, and make sure that testing is high on our priority list.
How Do We Test Architecture
The answer is, we don’t. Instead, we learn how to break the architecture down
to its component parts, working from the most primitive to the most sophisticated,
testing each component, and then integrating and testing the holistic
architecture. In other words, we have to divide the architecture, which in this
case is partly on-premise and partly in the clouds, into domains, such as services,
security, and governance, and test each domain using whatever approach
and tools are indicated. If this sounds complex, it is. The notion of SOA using
cloud computing is a loosely coupled complex interdependence, and the approach
for testing must follow the same patterns.
White Box and Black Box Testing
We use two major approaches to testing our architecture: black box testing and
white box testing.
Black box testing is the process of testing functions into which we do not
have complete visibility. For instance, we might ask a system to perform some
sort of behavior, such as to return information from an API call, and we would
not be able to see what happened inside that system as it accessed the database
and processed the information on behalf of the request.
Black box testing is most important when leveraging cloud computing
because we typically do not own, control, or have visibility into the inside of a
multitenant cloud computing system. Black box testing is the typical approach
in an SOA and cloud computing system, and we discuss how to approach black
box testing at the end of this chapter.
White box testing, in contrast, allows us to test a system while having complete
visibility into the system. When we ask a system to perform some sort of
behavior, such as returning information from an API call, we can see how the
request is internalized into the program, how the database request is formulated,
how the database is accessed, how the information returned from the
database is processed . . . you get the idea.