1. A computer system comprising: a first replica computer system that is configured to receive a new instance of a probe system that includes a probe head and a probe echo; a second replica computer system that is coupled to the first replica computer system and configured to receive a target record that includes a head field having an epoch value and a time stamp and an echo field having an epoch value and a latency value, wherein the probe head on the first replica computer system updates the epoch value and the time stamp in the head field when the probe echo is sent from the first replica computer system to the second replica computer system, and wherein the probe echo on the first replica computer system updates the epoch value and the latency value in the echo field when the probe echo is sent from the first replica computer system to the second replica computer system, if the epoch value in the echo field is less than the epoch value in the head field, the latency value being a measurement of time to communicate between the first and second replica computer systems; and a monitoring system that is coupled to the first and second replica computer systems and configured to generate a report that gives the communication latency for a communication starting in the first replica computer system and ending in the second replica computer system.