LR vs RPT
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LoadRunner-Vs-RationalPerformanceTester.doc
LoadRunner
LoadRunner works by creating virtual users who take the place of real users operating client software, such as Internet Explorer sending requests using the HTTP protocol to IIS or Apache web servers. Requests from many virtual user clients are generated by “Load Generators” in order to create a load on various servers under test. These load generator agents are started and stopped by Mercury’s “Controller” program. The Controller controls load test runs based on “Scenarios” invoking compiled “Scripts” and associated “Run-time Settings”.
Scripts are crafted using Mercury’s “Virtual user script Generator” (named “V U Gen”), It generates C-language script code to be executed by virtual users by capturing network traffic between Internet application clients and servers. With Java clients, VuGen captures calls by hooking within the client JVM. During runs, the status of each machine is monitored by the Controller.
At the end of each run, the Controller combines its monitoring logs with logs obtained from load generators, and makes them available to the “Analysis” program, which can then create run result reports and graphs for Microsoft Word, Crystal Reports, or an HTML webpage browser.
Each HTML report page generated by Analysis includes a link to results in a text file which Microsoft Excel can open to perform additional analysis.
Errors during each run are stored in a database which can be read using Microsoft Access
Rational Performance Tester
Rational Performance Tester (RPT) is a full load and monitoring suite that uses a distributed model to load test systems. RPT is not limited to Web server load testing, but can include specially written Java classes that can be used to load test other types of systems. RPT is based on the IBM Rational Software Development Platform (Rational SDP), which in itself is built on Eclipse. RPT refers to the graphical user interface (GUI). RPT is used in conjunction with the IBM Rational Agent Controller (RAC), which is a non-graphical application and used in distributed environments to generate load. The RPT GUI runs on the Windows or Linux platform. A RAC runs on the RPT machine and communicates with other RACs running on Linux, Windows, or z/OS platforms.
The scripts are compiled into Java classes and are sent to the other platforms that are running RAC. Any platform running RAC can then execute a test to the
target system.
There is no programming necessary to create, modify, or execute a load test. A load test is a graphical illustration of the Web pages that will be visited during execution. A SOCKS proxy is used to record a test script by navigating, through a browser, the Web pages that the test should capture and should mimic the actual use of a user of the system. The captured Web pages can be viewed and modified through a browser-like window in the RPT test editor
Test data can be varied during a test using a feature in RPT called a Data Pool.
RPT contains a Test Scheduler that allows for different characteristics of a load test to be changed or enhanced. This feature provides the ability to mirror the load that occurs on a running system. The scheduler features items such as run time, think time, statistic gathering, and overall user load.
RPT generates performance and throughput reports in real time, enabling detection of performance problems at any time during a load test run. These reports provide multiple filtering and configuration options that can be set before, during, and after a test run. Additional reports are available at the conclusion of the test run to perform deeper analysis on items, such as response time percentile distributions. Custom reports can be created. A custom report can be
tailored to the need of the tester one report to display information important to the tester. Reports can include bar, line, or pie charts.
Rational Performance Tester detailed architecture
Comparsion of LR and RPT
| Tool | Scripting |
|---|---|
| Load Runner | The Virtual User Generator (VuGen) allows a user to record and/or script the test to be performed against the application under test, and enables the performance tester to playback and make modifications to the script as needed. Such modifications may include Parameterization (selecting data for keyword-driven testing), Correlation and Error handling. During recording, VuGen records a tester’s actions by routing data through a proxy. The type of proxy depends upon the protocol being used, and affects the form of the resulting script. |
| RPT | Rational Performance Tester uses its own custom scripting language. These scripts can then be customized and organized in a variety of ways to accurately reflect the habits of the various user profiles expected to use the application once it goes live. Using a variety of automated data correlation techniques, these tests can then be executed to reflect multiple, unique, concurrent actors – scaling to even thousands or tens of thousands of users. Manual correlation is done using regular expressions. |
| Tool | Load Scenario Creation |
|---|---|
| Load Runner | The script generated by VuGen is run by the controller. Each run is called as a scenario with some preset settings. LoadRunner provides for the usage of various machines to act as Load Generators. For example, to run a test of 100 users, we can use three or more machines with Load generator installed in them. The tester will then provide the script and the name of the machine which is going to act as a load generator along with the number of users who are going to run from that machine. |
| RPT | There is no programming necessary to create, modify, or execute a load test. A load test is a graphical illustration of the Web pages that will be visited during execution. A SOCKS proxy is used to record a test script by navigating, through a browser, the Web pages that the test should capture and should mimic the actual use of a user of the system. The captured Web pages can be viewed and modified through a browser like window in the RPT test editor. This window shows what the user would see when visiting a selected page, helping to make more informed decisions about how to modify load tests prior to execution. |
| Tool | Load Test Feedback |
|---|---|
| Load Runner | LoadRunner uses Monitors to monitor the performance of individual components. But each monitor is to be purchased separately from Mercury. Some monitors include Oracle Monitors, Web Sphere Monitors, etc… Once a scenario is set and the run is completed, the result of the scenario can be viewed via the Analysis tool. |
| RPT | During test execution, Rational Performance Tester graphically displays consolidated views of the average response times – over time – for each simulated user profile. Testers also have the option of diving into the real-time conversation between any single user instance and the system under test to view the actual data passed back and forth, enabling rapid and early analysis of suspected response degradation. |
| Tool | Reporting |
|---|---|
| Load Runner | The Analysis tool takes the completed scenario result and prepares the necessary graphs for the tester to view. Also, graphs can be merged to get a good picture of the performance. The tester can then make needed adjustments to the graph and prepare a LoadRunner report. The report, including all the necessary graphs, can be saved in several formats, including HTML and Microsoft Word format. |
| RPT | RPT generates performance and throughput reports in real time, enabling detection of performance problems at any time during a load test run. These reports provide multiple filtering and configuration options that can be set before, during, and after a test run. Additional reports are available at the conclusion of the test run to perform deeper analysis on items, such as response time percentile distributions. Custom reports can be created. A custom report can be tailored to the need of the tester. Data from diverse sources can be combined on one report to display information important to the tester. Reports can include bar, line, or pie charts. |
| Tool | Environment Support |
|---|---|
| Load Runner | It supports a wide range of enterprise environments, including Web Services, Ajax, J2EE, and .NET.
LoadRunner 4.0 is available for the following client/server platforms: |
| RPT |
Creates, executes and analyzes tests to validate the reliability of complex e-business applications, including Seibel, SAP®, SOA and Citrix. Supports Windows, Linux and z/OS as distributed controller agents. |
| Tool | Ease of Use |
|---|---|
| Load Runner | LoadRunner now includes game-changing technology that reduces the script creation process down to a few simple mouse clicks. LoadRunner Click and Script enables you to record scripts at the user interface level The scripts are succinct, visually intuitive, and self-explanatory scripts. The scripts are easy to maintain. Click and Script lowers the technical skills needed to perform load tests. |
| RPT |
The automatic correlation in the script works most of the time. This is a big time saver.
The tool gives you the option of using a persistent cursor for your data tables. So if you had a test case that, for instance, deleted a user from a database, you would not have to restore the database or re-add users between test runs, you could just continue from the same point in your list of users. Rational® Performance Tester for z/OS includes multiple easy-to-use features with powerful testing capabilities, and delivers both high-level and detailed test views. |
| Tool | Technical Support |
|---|---|
| Load Runner | Mercury support is rated to be the best among testing tool and the developer can expect a reply from Mercury within 4 hours. |
| RPT | Though manuals, support hand books and rational help desk is available in the IBM website, the support is not up to mark compared to mercury. |
| Tool | Integration |
|---|---|
| Load Runner | Load Runner can be integrated with Mercury’s Test Director, which is a Test Management tool. |
| RPT | Integrates with Tivoli® composite application management solutions to identify the source of production performance problems. It can also be integrated with other Rational Products like Clear Case. |
Summary
While the above comparison shows the features rendered by the tools in each of the functionality we would like to say that you should use the demo-version of each product to see which meets your requirements. Based on your requirements, any of these tools could turn out to be the best for your need. Here are some of the strengths and weakness of tools to help you make your selection:
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LoadRunner-Vs-RationalPerformanceTester.doc
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This is quite precise article