A method and program product includes establishing a virtual private performance network for emulating different time zones and geographic traffic to simulate user patterns during a test session on an external networked system. A connection with a controller is established for accepting inputs for the test session. Load generators are configured with emulation parameters for the test session. The emulation parameters are based on the inputs from the controller. Resources of the load generators are monitored during the test session. Virtual users are added for varying a load on the external networked system for simulating the user patterns. A failover is detected of a failing load generator indicated by the monitoring. The test session is moved from the failing load generator to a failover generator upon the detection for continuing the test session and mitigating loss of data.