IBM Rational Performance Tester
Encyclopedia
IBM Rational Performance Tester is a tool for automated performance testing of web and server based applications from the Rational Software
Rational Software
Rational Machines was founded by Paul Levy and Mike Devlin in 1981 to provide tools to expand the use of modern software engineering practices, particularly explicit modular architecture and iterative development...

 division of IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

. It allows users to create tests that mimic user transactions between an application client and server. During test execution, these transactions are replicated in parallel to simulate a large transaction load on the server. Server response time measurements are collected to identify the presence and cause of any potential application bottlenecks. It is primarily used by Software Quality Assurance
Software quality assurance
Software quality assurance consists of a means of monitoring the software engineering processes and methods used to ensure quality. The methods by which this is accomplished are many and varied, and may include ensuring conformance to one or more standards, such as ISO 9000 or a model such as...

 teams to perform automated performance testing
Performance testing
In software engineering, performance testing is in general testing performed to determine how a system performs in terms of responsiveness and stability under a particular workload...

.

Overview

IBM Rational Performance Tester is a performance test automation tool used to measure web and server based application scalability. Using Rational Performance Tester, quality assurance teams can subject a web application or server to a large volume of transactions for the purpose of measuring the server response times. Lengthy response times are considered application bottlenecks, and information regarding these bottlenecks is typically passed along to application developers to correct, in an effort to decrease system response time. IBM Rational Performance Tester is an Eclipse
Eclipse (software)
Eclipse is a multi-language software development environment comprising an integrated development environment and an extensible plug-in system...

based performance test tool.

Performance Test Creation Process

The following is an overview of the process of system performance validation with IBM Rational Performance Tester

Test creation

Tests are created using the IBM Rational Performance Tester recording mechanism. The Rational Performance Tester recorder captures all transactions between application client (such as a web browser) and an application server. The resulting test is displayed as a tree view, where each branch of the tree represents a browser or client request and response.

Test editing

Rational Performance Tester tests are not represented as code. Rational Performance Tester tests are represented as a tree view, where each branch of the tree represents a browser or client request and response. To edit the test, the user selects menu options which allow for insertion of loops, "if-then" type decision structures, and response verification. Should a custom coding solution be required, users can insert Java code modules to perform complex computations.

Rational Performance Tester performs automatic test editing for data pooling and data correlation. With datapooling, Rational Performance Tester automatically edits tests to separate test data from the test actions. Test data, such as a user login ID and password values that were typed in by the user during the test, are stored in a spreadsheet like datapool. The test is crafted in such a way so that during test playback, each simulated user will access one row of the test data from the datapool. This ensures that each unique user uses unique data during playback, and prevents a situation where, for example, 100 simulated users attempt to login with a single user ID and password.

Data correlation is the process by which Rational Performance Tester ensures continuity between test actions. Often in a performance test a value is created at one step of a test and subsequently used during a later step. Whenever such a value is created, Rational Performance Tester stores that value in a variable, and uses that variable later on the test when the data is accessed. This prevents hard coding of values, and ensures that tests will play back correctly in dynamic data environments.

Test scheduling

Rational Performance Tester can execute a single test, or it can create a suite of tests for playback. When creating a suite of tests, users drag and drop tests onto a schedule to simulate a given sequence of events. Tests can be grouped by user profile, to represent the activities of different types of users on a system. The volume of transactions can be set to increase at defined intervals to increase load during a test, in an effort to identify system bottlenecks.

Test reporting

Rational Performance Tester offers a variety of reports to identify the presence and cause of system performance bottlenecks. There are reports that measure accuracy of system response which ensure that the system did not error out or crash during a test. There are reports to measure system performance metrics such as disk, network and CPU utilization, to identify the presence of hardware bottlenecks. To identify software related bottlenecks, there are reports to measure load, throughput and response times. For J2EE environments, when a bottleneck is identified, users can drill down on the performance reports to identify the cause of the bottleneck, identifying slow performance classes, methods and individual lines of application souce code.

Release history

The following is a release history of IBM Rational Performance Tester.
  • Rational Performance Tester 6.1 Released May, 2005. Initial release. Note this was this first release of the Eclipse based IBM Rational Performance Tester. IBM Rational previously offered Rational Performance Tester v6.0 which was a previous generation performance testing tool, unrelated to the current IBM Rational Performance Tester.
  • v7.0 Released February, 2007.
  • v8.0 Released October, 2008.
  • v8.1 Released July, 2009.
  • v8.2 Released October, 2010.

Criticisms

The primary criticism of performance test automation tools such as IBM Rational Performance Tester is that they can only find the performance bottlenecks that they are programmed to find. If a system performance bottleneck exists in an untested area of the system, Rational Performance Tester will not find the issue, and the system can go live without anyone's knowledge of the defect. Once the problem surfaces in a deployed system, organizations will experience all the related challenges of discovering and resolving a performance issue in production.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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