Use EventbusPerformance to start the performance test. Its monitoring the MessagePingPong verticle.
For non-cluster: Set EventbusPerformance.INSTANCES to your number of cores, which deploys that number of MessagePingPong on the eventbus.
For cluster: Set EventbusPerformance.INSTANCES=1 and use the commandline to start your number of cores vert.x environments. Use following parameters:
[vertx env 1] -cluster -cluster-host -cluster-port 25501
[vertx env 2] -cluster -cluster-host -cluster-port 25502
under linux you could use "sudo tcptrack -i lo" which shows the tcp traffic on loopback network interface where vertx envs will communicate over.