Analyze errors on a scenario run

Running a particular scenario will produce statistical results and provide a comprehensive list of all the errors (and assertions failures) occurring during the scenario run. The following screenshot shows the content of the Errors tab in Results mode after having run a particular scenario. As mentioned earlier, the information shown in this tab is very similar to that shown in the Check Virtual User dialog box.

Errors are also displayed by NeoLoad in Runtime mode during a scenario run, in the Runtime Errors tab.

The following points are where the Check Virtual User dialog box and the Errors tab differ:

• The Errors tab lists lines for HTTP requests only, contrary to the dialog box which presents a line for the HTML page a request belongs to. This is mainly because the Errors tab displays an error line for each type and each instance of a Virtual User played during the scenario.
• The Errors tab displays errors for each Virtual User played during the scenario, contrary to the dialog box which, by definition, concerns a unique user. A scenario defines a number of Virtual Users to be played. These users belong to different Populations and include different types of users. Hence, errors can occur for multiple users and multiple types of users.
  In the example, the scenario has errors concerning two types of users, SimpleUser and OccasionnalUser. NeoLoad numbers the users in the order they ran.
• The Errors tab provides the response and request preceding the request causing the error. In some situations, an error occurring on a request may be caused by the previous request or response, so easy access to those elements greatly helps in understanding an error cause.

The rest of this section details how the new elements provided by the Errors tab can be used.

Filtering and Sorting by Virtual Users

In the example, you may want to analyze the 500 error generated on the OccasionnalUser Virtual User. You may also want to concentrate on a particular user of this type, the OccasionalUser#5.

• Filtering: To only work with a particular type of user, the easiest way is to filter out the display of errors by selecting the type of user in the Virtual Users drop down list box.
• Sorting: Working with a particular user is easily achieved by sorting errors by Virtual User: clicking on the Virtual User column header.

Using the Previous Request

In the example, the GET request /loadtest/error has returned an HTTP 500 return code. This is the following error code : Internal Servlet error.

If you take a look at the previous request by selecting the previous request radio button , you understand that the loadtest/redirect/simple.jsp page has been requested.

You can now push your investigation a little further and display the response returned by the previous request by selecting the previous response radio button.

The response contains a 302 Moved Temporarily code redirecting the client Agent to the page called loadtest/error. The problem is therefore in the loadtest/redirect/simple.jsp which redirects to an error page. This simple example shows you how to meaningfully use the information NeoLoad provides concerning the context in which an error occurs.