The following section enumerates rules that you should follow when deploying and organizing your heavy load test infrastructure. They all refer to an ideal situation that, depending on your means and objectives, is not always realistic. But the closest you are to that situation, the more effective your heavy load testing will be.
For heavy load testing, the NeoLoad generators will need to open a large number of sockets. Make sure that the number of sockets allowed by your operating system is adequate. Refer to our troubleshooting guide for more details.
An efficient way to increase the load generators' performance is to distribute the generated requests over several network adapters. Once the adapters have been installed on the machine hosting the load generator, you simply need to select the adapters in the associated load generator's advanced setting to complete their configuration. The NeoLoad load generator distributes the load evenly across the installed network adapters.
During the test phase NeoLoad conveys three distinct types of information: Scenarios are dispatched from the controller to the load generators (scenario distribution), scenarios are actually played to the application servers (load generation) and finally, monitoring information is sent back to the controller. Separating those three information channels on distinct networks achieves the most efficient network setup. The following figure shows this ideal network configuration.
To obtain a good trade-off between infrastructure costs and efficiency, you can at least separate the load generation network from the monitoring network.
As seen in the above figure, keeping load generators physically close to the application servers will improve network performance. For the same reasons, it's a good idea to keep the controller close to the load generators. Also avoid having a firewall between load generators and your application servers.