Target-Based Performance Testing: Understanding TPS and Pacing in LoadRunner

TPS in Performance Testing

TPS (Transactions Per Second) is a key metric in performance testing that reflects system processing speed; higher TPS indicates faster processing, while lower TPS suggests the need for optimization.

Target-Based Performance Testing

LoadRunner allows the creation of manual or target‑based test scenarios. Users can select target types such as TPS or hits per second, set the desired target, and run the test to see whether the target is met.

After setting the target, the test runs automatically; the internal implementation is a black box to the user.

Setting Test Scenarios

Manual LoadRunner scenarios can be single‑transaction or mixed‑transaction. Two example screenshots illustrate both types.

Regardless of scenario type, the calculation principle for target TPS is the same.

Scenario Formula

The key fields are:

Virtual Users (vu)

Target TPS

Pacing

Thinktime

Thinktime is set to 0 seconds for all scenarios; pacing is the focus here.

Pacing defines the delay between action iterations. Option 3 sets an expected completion time for each iteration (e.g., pacing = 60 s). If the action finishes in 4 s, the remaining 56 s are idle; if it takes 120 s, the next iteration starts immediately.

When the action’s average response time fits within the pacing interval (“contained”), the target TPS can be achieved; otherwise it is not (“not contained”).

Example analysis shows the relationship:

Before the action’s response time exceeds pacing, target TPS = vu / pacing.

Using this formula, TPS can be accurately predicted and validated through extensive testing.

To achieve a desired TPS, set a pacing value (commonly 10 s or its multiples) and then adjust the number of virtual users; increasing vu or decreasing pacing raises the target TPS.

Recommended practice: fix pacing first, then increase vu as needed.

Conclusion

The article introduces a target‑based performance testing method, helping readers understand TPS settings, configure scenarios, and apply the underlying formulas to achieve clear, repeatable performance goals.