Agile Performance Testing - Testing Experience

Many testing techniques and methodologies developed over the
years also apply to web services based SOA systems. Through
functional, regression, unit, integration, system and process level
testing, the primary objective of testing methodologies is to increase
confidence that the target system will deliver functionality
in a robust, scalable, interoperable and secure manner.
Web services are the foundation of modern Service Oriented Architecture
(SOA). Typical web services include message exchange
between front end and back end using SOAP requests and responses
over the HTTP protocol.
A web service producer advertises its services to potential consumers
through Web Services Description Language (WSDL) – which
is an XML file that has details of available operations, execution
end-points and expected SOAP request-response structures.
Techniques such as Black, White and Gray Box testing applied to
traditional systems map also well into web services deployments.
However, the following characteristics of web services deployments
present unique testing challenges:
• Web services are basically distributed and are platform and
language-independent.
• Web services can be linked to dependencies on other thirdparty
Web Services that can change without notice.
SOA frameworks are a combination of web components, midtier
components, back-end and legacy systems. Unlike traditional
testing approaches, the SOA testing approach should include all
the aspects of business processes and also the integration framework.
The SOA test strategy should not only focus on just the functionality
or the front-end clients, but also on the integration layers.
It is therefore necessary to keep all these factors in mind when
creating an SOA test plan or strategy.
The following types of testing should be performed to ensure proper
end-to-end testing which enables coverage of the integration
framework:
• Functional testing
• Interoperability testing
• Performance testing
• Security testing
To test SOA, you need to go far beyond merely testing a user interface
or browser screen, as you will never find an attractive UI
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Testing SOA - An Overview
by Himanshu Joshi
while testing these apps. Some of the major challenges for SOA
testing include:
• No user interface for the services in SOA
• Application’s lack of visibility into loosely coupled business
level services
• Dependency on availability of any internal or external services
that offer a business function to perform end-to-end
testing.
The following aspects needs to be kept in mind when preparing
an SOA test approach:
• A web service is an application without UI.
• A GUI application should be developed
• Changes to web service interfaces often demand GUI changes
• Security testing of any web services that require encrypted
and signed data is not possible
• A web service should be validated for the client as well as at
the service level.
• The overall cost involved is very high for testing, development
& maintenance.
• Maintaining a pool of testing resources with SOA domain
knowledge
While testing web services, SOAP requests need to be generated
manually or using a supported third-party vendor testing tool.
Integrating a traditional functional testing tool or other thirdparty
tools of this kind is not feasible due to their nature and limitations.
Therefore some other web services testing tools come
into question.
These tools provide robust, reliable, scalable and interoperable
solutions. They are suitable for UI less testing. Just enter the
WSDL location and they can create basic functional tests for you.
Most of the tools even check your WSDL compliance to WS-I. They
also support asynchronous testing and data-driven testing using
data sources.
These test tools provide a solution for load testing and one of
their best features is their ability to fully reuse the functional
tests for load testing, which saves precious time.
Tools like SOAtest (http://www.parasoft.com) integrate with Qua-
84 The Magazine for Professional Testers www.testingexperience.com