SOA and SLA

Service Oriented Architecture (SOA) is all about Architectural paradigm (pattern/model), variety of heterogeneous systems (dissimilar), different locations and owners, and web services. SOA helps reduces expensive integration, allows for more asset reuse, increases business agility and most importantly reduces business risk.

Service-level agreement (SLAs) for SOA is a formal contract between a service provider and a consumer. The contracts in this regard are, service availability, performance, traffic levels, messages / queries per hour / minute / second, response time, rejected transactions, errors and so on.

Key to SOA Performance Testing

The key to successful performance testing in general require, understanding the application and the infrastructure, understanding the user/stakeholders of the application, generating accurate anticipated volumes of traffic, and investigating the impact of the traffic on the application and systems under test. SOA Adds Complexity to Performance Testing in terms of wide range of technologies, different applications and usages, different hardware / infrastructure, knowledge of the application and the technologies, and replicating the traffic patterns.

Overcoming Challenges

To simplify performance testing for SOA applications break them down into the smallest components possible, like individual Service, systems, databases, technology, protocols, messaging, and functionality. And then evaluate and analyze the performance of individual services based on components.

Adapting the methodologies like, narrowing the testing event to the smallest element/service and understanding the transaction, application service and the environment/systems, documenting the testing approach and the expected deliverables, developing automation to replicate transactions automation, performing Test Execution, monitoring the response time for the requests sent under varying traffic levels and the impact of the traffic on the application and infrastructure under varying traffic levels, measuring and analyzing the traffic patters to with the traffic/load, one can approach the concept.

SOA in details

SOA (Service Oriented Architecture) is an Architectural style, which is modular, shareable, distributable, and deals with defined interfaces. It is about the design of the business, focus on Business Processes / Business Driven; hence it is more than Web services!

Prior to SOA, a user or Financial Advisor needed to get into the business process of logging in, checking the credit, and getting into the loan quotation service and so on, which in response led to legacy/third party segment, i.e., the communication was possible via mainframe and its network, but now with the advent of SOA and Web Services we have an interface to the outside world.

The business risks involved are, increased costs, early joiner – when there is little knowledge, no business commitment and resource available, no overall picture of business processes and ability to prioritize, quality – single point of failure, the industry decides that the future isn’t SOA after all!

While the benefits are: reuse of code, reduced IT spend, and above all faster time to market.

Main Challenges and tips to face them

SOA fundamentally changes the traditional testing approach, and hence the testers face challenges like, scope and boundaries, changes to composition of test team, increased knowledge required of testers, technical knowledge (WSDL), domain knowledge, use of tools, governance and the need for standards, and increased focus on negative and non-functional testing.

To address the challenges, the Test Design should follow a top down approach, Test Execution should follow a Bottom up Approach starting at the individual service level, and the current testing methodologies should be extended to support the use of services in an SOA solution. Adding to it, the testers need to execute Functional and Regression Testing, Performance Testing, Security Testing, Integration Testing, and Interoperability, by meticulously planning the process.

Conclusion

SOA is here to stay for the foreseeable future and this will mean a different relationship between IT and the business and as a result testing will need to change. Hence, SOA will change the organizational testing methodology, and hence the testers’ skills and the approach will need to change accordingly.

When IT tunes to SOA for all its significant benefits, certain risks and issues while embarking on re-engineering its IT strategy and project delivery mechanisms, is stumbled upon. To rein in these risks and issues, QA and testing function must stand as the gatekeeper into IT operations. Quality objectives must be set corporately and adhered to, as poorly operating services risk would bring the entire organization to its knees!

Certain testing strategies are:

• Applying testing centre of excellence concept, so that there is a single repository of requirements, specifications, tools and test assets to understand and test the entire enterprise’s SOA services and supporting infrastructure.
• Perform a full traceability of the testing back from the user interface through to code level unit testing. Integrated test management, planning and execution allows SOA implementers to have confidence that a defect found at any stage in the development and deployment can be quickly identified, analyzed and resolved.
• Conducting performance test, security testing and Models Driven Testing are few such important testing strategies, which the SOA implementers should pay particular attention to.

Hence, by implementing modern QA and testing best practice and insisting on high quality delivery can an organization be fully prepared to meet the challenges of SOA implementation, and when the challenges are met, there is every chance of reaping the expected the rewards!