AppPerfect Load Test (AP LT) FAQ

What can I test with AppPerfect Load Test(AP LT)?

You can load test applications based on the following three protocols:

• HTTP
• JDBC
• Command Line Interface (CLI)

How specifically does AP LT help with load testing?

AP LT helps you easily record your test, help define parameters, executes the test and helps you analyze the results from your test.

Does AP LT support Secure HTTP (https) protocol? If so, how?

Yes, AP LT supports https load testing. To do this, you need to ensure your SSL certificate is issued with Thawte or VeriSign. If that is not the case, make you manually add your certificate to AP LT when asked for in the AP LT Project Properties dialog box.

My application requires a login and then uses the session information for subsequent interaction. Does AP LT support such applications? If so, how?

Yes, AP LT supports applications that require Basic authentication as well as those that require application authentication. If a session ID is returned by your application, you can specify the session ID's name as AP LT can re-use it in all requests it makes.

How many virtual users does AP LT support? How many virtual users will my machine support?

Your system's resources determine how many virtual users it will support. Assuming a 2.4 GHz or higher Pentium IV CPU, each virtual users should require about 0.75 MB of RAM.

How are tests recorded using a browser ? How does the proxy server work?

AP LT acts as a proxy server that sits between your Web browser and your server application. All traffic between the two get recorded by AP LT.

How does AP LT calculate the response time for a given request?

AP LT keeps track of the time the request was made and the complete response was received. This time interval is the response time for that request.

What does browser simulation mean? Why should I care?

There are subtle differences between MS IE and Mozilla/Firefox. Depending on your user base, it often makes sense to load test your application using these two profiles. AP LT has the ability to simulate low-level port connectivity behavior of each of these browsers for more accurate load testing.

What are pass-through parameters? How do they work?

Parameters that change DURING runtime are called pass-through parameters. These parameters are fully supported in AP LT. You only need to select the pass-through in data source drop down for the parameter name to inform AP LT that this is a pass-through parameter. Then the values that are provided for the pass-through parameter while replaying a recorded test, are picked at run time so that the behavior of the application can be correctly simulated.

How do I monitor the machine on which the target application is running?

Please go to System Monitoring perspective and add machine to monitor.

What does a "load strategy" mean ? What are the various load strategies available?

Load Strategy allows you to provide various combinations of user access with respect to time and number of hits. You can choose to loop users through a test, or allow users to access the application incrementally or in a burst etc. Please see the chapter Load Strategies for more details.

What is "think time"? How does it impact a test?

Think time is the time a user takes to click through to the next page from the current one. If you choose to record think time and provide a value for it, then the time out value of your test will be considered after considering the think time. For example, if you have provided think time value as: 10 seconds and time out value as: 20 seconds, then AP LT will wait for a total of 30 seconds before it times out a task.

How do I generate reports and track trends?

These features are part of AppPerfect Test Manager product.

How does AP LT determine if a request is a success or a failure?

Depending on the type of test, definition of successful or failed hit varies:

• HTTP Test: AP LT checks for the response code to determine success or failure. For the most part, response codes 100 through 399 are considered success. Code 400 and above are considered failed requests. If additional validation has been specified, those are used to validate tests as failed or successful.
• Database Test: Based on validations specified, those are used to validate tests as failed or successful.

I want to schedule AP LT to run at a set time in the future. How do I do that?

Scheduling of Load Test can be achieved using AppPerfect Test Manager product.

Can I run AP LT on multiple machines and simultaneously test the same target application?

Yes, it can be done by configuring tool to Run project simultaneously on multiple machines at Project -> Properties.. -> Machine Settings

Can I configure AP LT for monitoring CPU, Memory, Disk performance data from 2 target servers?

Yes, you can monitor as many machines as you want by configuring System monitoring at Project -> Properties.. -> Machine Settings.

How do I relate the system monitoring data i.e. CPU, Memory, Network usage, and disk activity to the tasks in action groups? The purpose is to analyze data e.g. if there was a peak in disk activity, what task was being performed?

The analysis of data needs to be done manually. Lets say you see peak in disk activity after 30 seconds from test start, now you need to look at each task detail and see what was the task getting hit at that time. You can select individual task details and look at Hit count chart and see which task was getting executed at that time.

I configured a Load Test to run for 5 minutes. However it did not stop after 5 minutes, I had to stop the test manually after several minutes. Why is that?

This is likey to happen in case you are using Loop Strategy for the test. Loop Strategy is independent of time. Each virtual user will loop through the entire test for the given number of loop counts. Please change the strategy to any other type to stop test in 5 minutes.

I have downloaded the evaluation version of AppPerfect LoadTest. I am trying to execute the tasks mentioned in the Load Test tutorial using the bundled PetStore project, but no tasks are getting recorded under ActionGroup. Is recording supported in Evaluation version?

Yes, recording is supported in Evaluation version as well. Please make sure the Proxy Settings are properly configured in the browser as AP LT uses the proxy server to record tests.

Start recording in Load Test. Once the browser is launched, check the proxy settings of the browser (Tools -> Internet Options... Connections tab, LAN settings). Incase of Internet Explorer, check if "Bypass proxy settings for local address" option is selectd. If yes, then deselect that option. Similarly, if you are using Firefox or Netscape browser check if "localhost,127.0.0.1" is present in the "No proxy for" field of the Connection Settings dialog. Remove the same if present and then continue recording. It should work.

I tested AP LT with a web application with Oracle database in the backend. I faced a problem regarding the database getting full. Is there any facility to rollback changes in the database?

Since Load Testing simulates the real time environment, and while loadtesing all we do is fire all the http requests that were recorded. So if these requests are resulting in doing any database interaction at application side then this needs to be handled at application side itself. Since DB transaction could also result in peformance bottleneck so removing database transaction from the application side for LoadTesting is not correct solution. What you can do is one of the following::

1. The Best way to deal with this problem is also record tasks that would delete the entries that were added. So basically if you do some action on your webpage which results in addition of few details to database, so in case there is also front end available to delete those recorded entries from DB then record the tasks for that as well. This way Load Test will execute all the tasks resulting in addition and deletion of database entries, hence clearing the data automatically.
2. For testing purpose you can create a dummy database and set your application to use that instead of your production database. Or You can write scripts at you server side which would clear database after the Load testing is completed.

I'm getting an error again and again. I've tried everything, but I'm stuck. What should I do?

• Close the currently opened project if it is open. Stop and close the application if it is running.
• Go to Tools ->Options-> Log Settings. Make sure the settings selected for all the products is: Debug (not Fatal).
• Open the project. Perform the operations that are giving you the error. The moment you get the error, stop all operations and send us the following files:
  1. All files present in <LoadTest_Home>\logs folder.
  2. Project file i.e. *.adt file of that project.
  3. Build number of the application. (Help->About AppPerfect...)