Dr. Dobb's Journal - November 2008 - (Page 46)

Best Practices Special by Arunava Chatterjee Testing Service-Oriented Architectures And a SOA testing harness written in Ruby! Traditional testing techniques assume defective code can be precisely determined. But this isn’t Arunava is a Technical Architect at BearingPoint working on SOA and Java Enterprise Architectures. He holds a Ph.D. in Physics from Florida State University and can be contacted at chatterjeeb@yahoo.com. always the case when Service-Oriented Architectures (SOAs) are involved. SOA implies a network of distributed nodes, some of which may be clustered, redundant, or maintained by other organizations. Consequently, isolating problems in a system can be demanding. Also, SOA systems tend to be always online, even when new services are introduced to or removed from live systems. For these reasons, SOA testing presents a level of opacity that more traditional systems avoid. To address these problems, SOA testing must leverage best practices from existing testing methodologies and create new approaches. In this article, I discuss SOA testing and present a SOA test harness. TestingInAServiceOrientedWorld.pdf). While useful, this approach often lacks the granularity necessary in debugging complex applications. Another potentially more complete solution to the problem is to isolate the services of interest within a harness that simulates the behavior of the system at the boundaries, then monitor each service in the system. SOA Testing In testing SOA, traditional test practices should not be abandoned. But because of SOA’s distributed and technologically heterogeneous nature, testing best practices need to be extended. As with non-SOA code, unit testing of a service is a necessary first step, offering the first line of defense against defects in implementing services. Likewise, integration testing is a necessity as service choreography and orchestration become the means to support business processes. In the world of SOA integration testing, services may be provided without code from other groups or hosted outside of the testing environment. With this in mind, it becomes increasingly apparent that what is required for testing in SOA environments is the ability to monitor the inputs and outputs of each service, validate data at each node, and assess the behavior of each node under different loads and constraints. As the number of services grow, it becomes essential to monitor the relevant services of a business process or use case in a controlled manner. One solution to this problem assumes that an Enterprise Service Bus is used and can emit debugging and auditing information as messages pass through (www.crosschecknet.com/soa_testing/ 46 Dr. Dobb’s Journal l www.ddj.com l November 2008 Unit Testing Unit testing in SOA is not only the testing of components comprising a service, but also the testing of individual services in isolation. This can be done using a static or dynamic client that invokes the service. In this manner, functional and nonfunctional testing on a service can be done. Validity of the content in the request or response can be assessed via XPath or XQuery statements. This is perhaps the easiest of the tests to perform because preexisting Dynamic Invocation Interface (DII) clients are available (java .sun.com/j2ee/1.4/docs/tutorial-update2/doc/ JAXRPC5.html). Integration Testing Integration testing in SOA is the testing of multiple services in the fulfillment of a use case or business process. Again, challenges arise in transparency within and among services since some of these services can cross organizational boundaries and leverage external systems. Perhaps the most conceptually straightforward approach to integration testing of SOA is to use service proxies substituting for existing services. This lets the http://www.crosschecknet.com/soa_testing/TestingInAServiceOrientedWorld.pdf http://java.sun.com/j2ee/1.4/docs/tutorial-update2/doc/JAXRPC5.html http://java.sun.com/j2ee/1.4/docs/tutorial-update2/doc/JAXRPC5.html http://java.sun.com/j2ee/1.4/docs/tutorial-update2/doc/JAXRPC5.html http://www.crosschecknet.com/soa_testing/TestingInAServiceOrientedWorld.pdf http://www.ddj.com

Table of Contents Feed for the Digital Edition of Dr. Dobb's Journal - November 2008

Dr. Dobb's Journal - November 2008 Contents Friday Night Fish Fry Alia Vox Developer Diaries Developer's Notebook Saving Open Source Conversations iPhone Building Your Own Web Server Green Telnet What's New In Boost Threads? Testing Service Oriented Architectures Test Case Generation, UML, and Eclipse Unit Testing Web Services C3 Programming The Agile Edge Swaine's Flames Effective Concurrency

Dr. Dobb's Journal - November 2008

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