To execute a load test, LoadView emulates virtual users interacting simultaneously with a target web resource, so-called Concurrent Users. Herewith, each virtual user performs a sequence of actions specified by the device. In terms of LoadView, a Session is one completed run of the device by one virtual user.

In other words, each virtual user will be executing the device runs until the completion of the test. A sum of all runs that each virtual user will be able to do will give us the total number of sessions. Prior to the test execution, the system estimates the number of sessions by taking into account device duration time, overall test duration, the number of virtual users, and the load curve pattern.

To understand better how concurrent load testing works, please see our explainer video.

The Estimated Number of Sessions for the Test

During the device validation process, the system calculates how long it takes to execute a single-user device run, known as Device Duration Time. Based on that value, and knowing the duration of the test and the number of virtual users, the system estimates the total number of completed sessions.

To put it another way, the Estimated Sessions value represents the number of sessions that the system can execute under ideal conditions.

Why the Discrepancy in Estimated and Result Number of Sessions Occurs

Due to its nature, the Estimated Session value is preliminary and does not precisely define a load test result. The number of completed sessions will differ depending on the fluctuations in server performance and response time, or errors that occurred during the test execution.

For example, if a target server’s performance has dropped under the load, the response time may grow, and as a result, it may take more time to complete a single session. Here, the session duration time will increase under the load and the actual number of sessions will be less than the estimated value.

How to Limit the Number of Test Sessions

If you want to execute a specific number of load test sessions during a load test run, enable the Limit Sessions option in the Load Type section and specify the limit in the related field. See the Limiting the Number of Test Sessions article for details