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How to write a performance test case « My Load Test

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How to write a performance test case
I have decided to release an early draft of this document so that others may provide feedback. Please let me know what you think. Writing test cases for performance testing requires a different mindset to writing functional test cases. Fortunately it is not a difficult mental leap. This article should give you enough information to get you up and running. First, lets set out some background and define some terms that are used in performance testing. Test case – a test case is the same as a use case or business process. Just as with a functional test case, it outlines test steps that should be performed, and the expected result for each step. Test script – a test script is a program created by a Performance tester that will perform all the steps in the test case. Virtual user – a virtual user generally runs a single test script. Virtual users do not run test scripts using the Graphical User Interface (like a functional test case that has been automated with tools like WinRunner, QuickTest, QARun or Rational Robot); they simulate a real user by sending the same network traffic as a real user would. A single workstation can run multiple virtual users. [Would a diagram be useful here?] Scenario – a performance test scenario is a description of how a set of test scripts will be run. It outlines how many times an hour they will be run, how many users will run each test script, and when each test script will be run. The aim of a scenario is to simulate real world usage of a system. Writing a test case for performance testing is basically writing a simple Requirements Specification for a piece of software (the test script). Just as with any specification, it should be unambiguous and as complete as possible. Every test case will contain the steps to be performed with the application and the expected result for each step. As a performance tester will generally not know the business processes that they will be automating, a test case should provide more detail than may be included in a functional test case intended for a tester familiar with the application. It is important that the test case describes a single path through the application. Adding conditional branches to handle varying application responses, such as error messages, will greatly increase script development time and the time taken to verify that the test script functions as expected. If a test script encounters an error that it does not expect, it will usually just stop. If the Project Manager decides that test scripts should handle errors the same way a real user would, then information should be included on how to reproduce each error condition, and additional scripting time should be included in the project plan. The main reason a user may be presented with a different flow through the application is the input data that is used. Each test case will be executed with a large amount of input data. Defining data requirements is a critical part of planning for a performance test, and is the most common area to get wrong on a first attempt. It is very easy to forget that certain inputs will present the user with different options.

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consideration should be given to the non-obvious details of how it is iterated. then a test scenario may be generating too many logins if the real users generally stay logged into the application. a performance test case may need to be refined as questions are raised by the performance tester.How to write a performance test case « My Load Test http://www. Starting the client application takes 10 seconds and logging in takes 5 seconds but. When a script is iterated.com/how-to-write-a-performance-test-case/ The other important data issues to identify are any data dependencies and any potential problems with concurrency. the transaction timing point will only measure 5 seconds. Information on how the test steps will be iterated should be included in the test case. then it should be noted as a limitation of the performance test effort. A good example would be a client application that runs on a user’s PC. and a technical expert should assess the likely impact. This means that any operations that happen only on the client do not get simulated and therefore do not get included in any transaction timing points. An example test case: Стр. and communicates with a server. Some performance test tools make these details easier to change than others. and the entire test case is iterated by the virtual user. including the time users take to enter data or spend looking at the screen is simulated with user think time – an intentional delay that is inserted into the test script. a performance test case will be run many times (iterated) by the same virtual user in a single scenario. For example.myloadtest. A good example would be a test script simulating users using an Internet search engine. It can be difficult for a performance tester to debug test script failures with little knowledge of the application. will data modified by virtual users cause other virtual users to fail when they try to use the same data? The test tool can partition the data used by each virtual user if these requirements can be identified. if a test case involves a user logging in and performing a search. should the virtual user establish a new network connection and empty their cache or should every iteration simulate the same user conducting another search? As all performance test tools have different default behaviours. Operations that only happen on the client. Depending on the sophistication of the performance test tool. such as the time it takes for a search to return a result set. simulating a new search operation. Think times are generally inserted outside of any transaction timing points anyhow. It is important to remember that the test script is only creating the network traffic that would normally be generated by the application under test. especially if the failures only occur when multiple virtual users are running at once. Any test cases provided to a performance tester should clearly define the start and end points for any transaction timings that should be included in the test results. Is it important that data is used in some business functions before they are used in others? And. rather than a functional test case. If it is not practical to emulate all the attributes of the expected system traffic with a particular tool. the user think time may be automatically excluded from the transaction timing points. virtual users will execute the steps of the test case as fast as they can. 2 из 6 10.04. Hopefully this article has provided some insight into the extra considerations that must be given when writing a performance test case. One of the most important pieces of information a performance test is designed to discover is the response time of the system under test – both at the overall business function level and at the low level of individual steps in the test case. If no think time is included. While a functional test case will be run once from start to finish. As with any software specification. since only the login is sending network traffic to the server.2012 17:50 . When the test script is iterated. [Is there a way to break up this sentence?] A more realistic test case may have the virtual user log in once and then keep doing the same action for as long as the virtual user is run. a good performance tester should clarify this type of detail with business and technical experts. resulting in greater (and unrealistic) load on the system under test.

2005 at 7:06 pm and is filed under Blog.smartbear.com/how-to-write-a-performance-test-case/ Tags: Performance Testing This entry was posted on Monday.com/site-monitoring 13 Responses to “How to write a performance test case” Стр.04. Start Free Trial.How to write a performance test case « My Load Test http://www. February 14th. Site Performance Issues? Identify Site Speed Problems 24/7. 3 из 6 10.2012 17:50 .myloadtest. www. Instant Alerts.

for example. I do plenty of work in both WR and LR. Your explanation about writing test cases are very good. 2007 at 3:13 pm Hi Stuar. thanks.nadkarni@yahoo. Bithika says: February 14. Will it not be confusing. Chris Reply 4. i will like to discuss a few things with you. I am wondering if you could help me here. 4 из 6 Amit says: 10. 2005 at 1:26 pm Dear Stuar. As suppose there is an enhancement in the mid portion of the application and since we will be over with writing test cases how will we write the new test cases from the middle. Srinivas says: August 9. I am wondering if there is a standard for software performance testing??? What I mean is some thing define how a high-quality software unit sould pass a performance test. Your performace test case topic is awsome. 2005 at 2:32 am Well done. Стр.2012 17:50 .myloadtest. 2005 at 7:44 pm Shared Run-time Setting mode is disabled for what type of Vuser? Reply 3. hoping to talk to u soon. Thanks.How to write a performance test case « My Load Test http://www. Well I have been in Testing for over 5 years but have never got an opportunity to do performance testing.04. However. This is kind of really urgent. Ronak says: January 24.com & give me your contact information. Very interesting to go through the details. Please write in to me at ronak. Thank you Reply 5. it does help me lots. reaponse time must be Reply 2. Nghia says: August 4. Christopher Meisenzahl says: August 20. Please clarify this doubt.com/how-to-write-a-performance-test-case/ 1. 2008 at 11:03 pm Hi Sutar. Can you please tell me how to write test cases for regression testing. but here comes 1 now. Ronak Reply 6.

Reply 10. Your explanation about writing test cases are very good. 2008 at 9:55 pm Your way of explaing about perfomance testing is very nice.04. I am working on the application where there are 3 environments and I have to create a script for each environment. 2008 at 12:49 am Your explanation is wonderful for writing test case. I am looking forward to use the single script for all 3 enviornments. Now.myloadtest. This artical helped me a lot . I would like to know that the created stress script for testing enviornment can be helpful for production environment??? If yes then how to replace the prod url with test url.How to write a performance test case « My Load Test http://www. But I want to know that if there is a scenario or scenario’s in which you have to run multiple scripts at one instance with the load distributed among the scripts. Amit Khare says: June 6. sadhana says: April 4. It will be great if you can help me out for the same. Thank you Reply 11. then how will you write the test case.2012 17:50 . I want u to give more examples of other test cases like regresstion testing etc. 5 из 6 10. Thanks… Reply 9. Can you please tell me how to write test cases for DNS load testing. Srinivas says: February 26.Please give your contact details phone number or mail id. 2008 at 7:02 pm Hi. 2008 at 8:58 pm Hi.I have a question on formance test planning.com Reply 8. Neha says: February 29. Thanks Reply 7.com/how-to-write-a-performance-test-case/ February 18. Please clarify .bonthu@gmail. Loken says: Стр. Hi Stuar. 2008 at 10:43 pm Your explanation is wonderful. My id is sree.

hoping to view more articles and examples from you… Reply 12. Reply 13.04. 6 из 6 10.How to write a performance test case « My Load Test http://www. I find it useful to my current line of field. Your explanation is good.com/how-to-write-a-performance-test-case/ June 25. Reply Leave a Reply Name (required) Mail (will not be published) (required) Website All original content from My Load Test is copyright © Stuart Moncrieff. kavitha says: May 26. Good work. 2008 at 2:32 pm Your article is very interesting and informative. I want You to give a good example of regression testing and functionality testing. But I would like to know more on how Performance testing is done on WEB Search engines & the standards required for the same.myloadtest. Стр. Sreejith says: August 6. 2009 at 5:22 pm I liked to ur way of presentation about the performance testin.2012 17:50 . I was just wondering if you also could write some examples as well as articles on test case specifications against scenarios in the near future. 2008 at 6:23 pm Hi.