Service virtualization

Last updated

In software engineering, service virtualization or service virtualisation is a method to emulate the behavior of specific components in heterogeneous component-based applications such as API-driven applications, cloud-based applications and service-oriented architectures. It is used to provide software development and QA/testing teams access to dependent system components that are needed to exercise an application under test (AUT), but are unavailable or difficult-to-access for development and testing purposes. With the behavior of the dependent components "virtualized", testing and development can proceed without accessing the actual live components. Service virtualization is recognized by vendors, industry analysts, and industry publications as being different than mocking. [1] [2] See here for a Comparison of API simulation tools.

Contents

Overview

Service virtualization emulates the behavior of software components to remove dependency constraints on development and testing teams. Such constraints occur in complex, interdependent environments when a component connected to the application under test is:

Although the term "service virtualization" reflects the technique's initial focus on virtualizing web services, service virtualization extends across all aspects of composite applications: services, databases, mainframes, ESBs, and other components that communicate using common messaging protocols. [3] [4] [5] Other similar tools are called API simulators, API mocking tools, over the wire test doubles.

Service virtualization emulates only the behavior of the specific dependent components that developers or testers need to exercise in order to complete their end-to-end transactions. Rather than virtualizing entire systems, it virtualizes only specific slices of dependent behavior critical to the execution of development and testing tasks. This provides just enough application logic so that the developers or testers get what they need without having to wait for the actual service to be completed and readily available. For instance, instead of virtualizing an entire database (and performing all associated test data management as well as setting up the database for every test session), you monitor how the application interacts with the database, then you emulate the related database behavior (the SQL queries that are passed to the database, the corresponding result sets that are returned, and so forth). [6] [7]

Application

Service virtualization involves creating and deploying a "virtual asset" that simulates the behavior of a real component which is required to exercise the application under test, but is difficult or impossible to access for development and testing purposes.

A virtual asset stands in for a dependent component by listening for requests and returning an appropriate response—with the appropriate performance. For a database, this might involve listening for a SQL statement, then returning data source rows. For a web service, this might involve listening for an XML message over HTTP, JMS, or MQ, then returning another XML message. The virtual asset's functionality and performance might reflect the actual functionality/performance of the dependent component, or it might simulate exceptional conditions (such as extreme loads or error conditions) to determine how the application under test responds under those circumstances.

Virtual assets are typically created by:

They are then further configured to represent specific data, functionality, and response times.

Virtual assets are deployed locally or in the cloud (public or private). With development/test environments configured to use the virtual assets in place of dependent components, developers or testers can then exercise the application they are working on without having to wait for the dependent components to be completed or readily accessible. [3] [4] [7]

Industry analysts report that service virtualization is best suited for "IT shops with significant experience with 'skipping' integration testing due to 'dependent software', and with a reasonably sophisticated test harness. [8]

Relation to stubbing and mocking

An alternative approach to working around the test environment access constraints outlined in this article's introduction is for team members to develop method stubs or mock objects that substitute for dependent resources. The shortcoming of this approach became apparent in the early 2000s with the rise of Service-oriented architecture. [9] The proliferation of Composite applications that rely on numerous dependent services, plus the rise of Agile software development following the 2001 publication of the Agile Manifesto, made it increasingly difficult for developers or testers to manually develop the number, scope, and complexity of stubs or mocks required to complete development and testing tasks for modern enterprise application development. [10]

The first step in the evolution from stubbing to service virtualization was the technology packaged in SOA testing tools since 2002. [11] The earliest implementations of service virtualization were designed to automate the process of developing simple stub-like emulations so that composite applications could be tested more efficiently. [12] As enterprise systems continued to grow increasingly complex and distributed, software tool vendors shifted focus from stubbing to the more environment-focused service virtualization. [2] While stubbing can still be completed through manual development and management of stubs, what has become known as "service virtualization" is completed by using one of the available commercial off the shelf (COTS) service virtualization technologies as a platform for the development and deployment of their "service virtualization assets". [10]

Agile and DevOps

The increasing popularity [13] of Agile software development and DevOps has created demand for a new set of tools to deliver service virtualization to communities that work in this way. [14] Practices such as Continuous delivery and moving away from mainframe and monolith development to more distributed microservice-based architectures fit well with the capabilities of service virtualization. Agile and DevOps teams prefer to work with lightweight tools that have less accumulated bloat and no cumbersome licensing restrictions. [15]

See also

Related Research Articles

Software testing is the act of examining the artifacts and the behavior of the software under test by validation and verification. Software testing can also provide an objective, independent view of the software to allow the business to appreciate and understand the risks of software implementation. Test techniques include, but are not necessarily limited to:

In software quality assurance, performance testing is in general a testing practice performed to determine how a system performs in terms of responsiveness and stability under a particular workload. It can also serve to investigate, measure, validate or verify other quality attributes of the system, such as scalability, reliability and resource usage.

In software engineering, service-oriented architecture (SOA) is an architectural style that focuses on discrete services instead of a monolithic design. By consequence, it is also applied in the field of software design where services are provided to the other components by application components, through a communication protocol over a network. A service is a discrete unit of functionality that can be accessed remotely and acted upon and updated independently, such as retrieving a credit card statement online. SOA is also intended to be independent of vendors, products and technologies.

In software testing, test automation is the use of software separate from the software being tested to control the execution of tests and the comparison of actual outcomes with predicted outcomes. Test automation can automate some repetitive but necessary tasks in a formalized testing process already in place, or perform additional testing that would be difficult to do manually. Test automation is critical for continuous delivery and continuous testing.

In software testing, a test harness or automated test framework is a collection of software and test data configured to test a program unit by running it under varying conditions and monitoring its behavior and outputs. It has two main parts: the test execution engine and the test script repository.

Mobile app development is the act or process by which a mobile app is developed for one or more mobile devices, which can include personal digital assistants (PDA), enterprise digital assistants (EDA), or mobile phones. Such software applications are specifically designed to run on mobile devices, taking numerous hardware constraints into consideration. Common constraints include CPU architecture and speeds, available memory (RAM), limited data storage capacities, and considerable variation in displays and input methods. These applications can be pre-installed on phones during manufacturing or delivered as web applications, using server-side or client-side processing to provide an "application-like" experience within a web browser.

Azure DevOps Server is a Microsoft product that provides version control, reporting, requirements management, project management, automated builds, testing and release management capabilities. It covers the entire application lifecycle, and enables DevOps capabilities. Azure DevOps can be used as a back-end to numerous integrated development environments (IDEs) but is tailored for Microsoft Visual Studio and Eclipse on all platforms.

Parasoft SOAtest is a testing and analysis tool suite for testing and validating APIs and API-driven applications. Basic testing functionality include functional unit testing, integration testing, regression testing, system testing, security testing, simulation and mocking, runtime error detection, web UI testing, interoperability testing, WS-* compliance testing, and load testing.

<span class="mw-page-title-main">Parasoft</span> Software testing framework

Parasoft is an independent software vendor specializing in automated software testing and application security with headquarters in Monrovia, California. It was founded in 1987 by four graduates of the California Institute of Technology who planned to commercialize the parallel computing software tools they had been working on for the Caltech Cosmic Cube, which was the first working hypercube computer built.

API testing is a type of software testing that involves testing application programming interfaces (APIs) directly and as part of integration testing to determine if they meet expectations for functionality, reliability, performance, and security. Since APIs lack a GUI, API testing is performed at the message layer. API testing is now considered critical for automating testing because APIs now serve as the primary interface to application logic and because GUI tests are difficult to maintain with the short release cycles and frequent changes commonly used with Agile software development and DevOps.

Parasoft DTP is a development testing solution from Parasoft that acts as a centralized hub for managing software quality and application security. DTP provides a wide range of traditional software reports from normal software development activities, such as coding and testing, and is also able to aggregate data from various software testing practices to present a comprehensive view of the state of the codebase. DTP provides software testing analytics via an internal intelligence engine.

In computer programming and computer science, programmers employ a technique called automated unit testing to reduce the likelihood of bugs occurring in the software. Frequently, the final release software consists of a complex set of objects or procedures interacting together to create the final result. In automated unit testing, it may be necessary to use objects or procedures that look and behave like their release-intended counterparts, but are actually simplified versions that reduce the complexity and facilitate testing. A test double is a generic (meta) term used for these objects or procedures.

Continuous testing is the process of executing automated tests as part of the software delivery pipeline to obtain immediate feedback on the business risks associated with a software release candidate. Continuous testing was originally proposed as a way of reducing waiting time for feedback to developers by introducing development environment-triggered tests as well as more traditional developer/tester-triggered tests.

<span class="mw-page-title-main">Parasoft C/C++test</span> Integrated set of tools

Parasoft C/C++test is an integrated set of tools for testing C and C++ source code that software developers use to analyze, test, find defects, and measure the quality and security of their applications. It supports software development practices that are part of development testing, including static code analysis, dynamic code analysis, unit test case generation and execution, code coverage analysis, regression testing, runtime error detection, requirements traceability, and code review. It's a commercial tool that supports operation on Linux, Windows, and Solaris platforms as well as support for on-target embedded testing and cross compilers.

Parasoft Virtualize is a service virtualization product that can create, deploy, and manage simulated test environments for software development and software testing purposes. These environments simulate the behavior of dependent resources that are unavailable, difficult to access, or difficult to configure for development or testing. It simulates the behavior of dependent resources such as mainframes, ERP systems, databases, web services, third-party information systems, or other systems that are out of direct developer/tester control. The product is used in conjunction with hardware/OS virtualization to provide developers and testers with the resources they need to execute their development and testing tasks earlier, faster, or more completely. Its technologies for automating continuous testing are used as part of continuous delivery, continuous integration, and continuous release.

Wilma is a Service virtualization software tool that computer programmers and testers use for developing and testing other software. It sits between software components, software services, microservices, as a transparent proxy, and captures the communication traffic between the software components. Based on its actual configuration, evaluates the captured messages and decides between proxying the request or providing response by itself, as a service stub. Therefore, it is a combined Transparent Proxy and Service Stub. It is written in Java, and Open Sourced under the license GPL.

<span class="mw-page-title-main">DevOps toolchain</span>

A DevOps toolchain is a set or combination of tools that aid in the delivery, development, and management of software applications throughout the systems development life cycle, as coordinated by an organisation that uses DevOps practices.

This article discusses a set of tactics useful in software testing. It is intended as a comprehensive list of tactical approaches to Software Quality Assurance (more widely colloquially known as Quality Assurance and general application of the test method.

The tools listed here support emulating or simulating APIs and software systems. They are also called API mocking tools, service virtualization tools, over the wire test doubles and tools for stubbing and mocking HTTP(S) and other protocols. They enable component testing in isolation.

References

  1. ↑ Service Virtualization as an Alternative to Mocking, by Jonathan Allen, eBizQ April 22, 2013
  2. 1 2 What is Service virtualization, by James Day, Medium Jun 18, 2021
  3. 1 2 Managing Test Environments by Liz McMillan, Cloud Computing Journal, December 2011
  4. 1 2 Application Behavior Virtualization by Elizabeth White, Cloud Computing Journal, December 2011
  5. ↑ Database Virtualization For Development and Test by Wayne Ariola, ST & QA Magazine, March 2012
  6. ↑ An Intro to SOA and Virtualization Archived 2011-11-22 at the Wayback Machine by John Michelsen, WebServices.org, August 2007
  7. 1 2 The Next Generation of Test Environment Management by Wayne Ariola, Virtualization Journal, July 12, 2011
  8. ↑ Parasoft and "Service Virtualization" Testing: A Good Idea by Wayne Kernochan, Thoughts From a Software IT Analyst, February 22, 2013
  9. ↑ Testing in Service-Oriented Environments by Ed Morris et al, Software Engineering Institute, March 2010
  10. 1 2 Service virtualization is helping organizations realize business value from testing by Chandranshu Singh, ovum, March 31, 2014
  11. ↑ Parasoft's Web Service Testing Tool Should Aid Development by Theresa Lanowitz Gartner, May 1, 2002
  12. ↑ SOA virtualization gets real by Rich Seeley, SearchSOA, November 28, 2007
  13. ↑ Agile & DevOps Google Trends
  14. ↑ Next Gen Service Virtualization Forum, 13th of September 2017
  15. ↑ Thought Works Technology Radar: Big enterprise solutions
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.