1. One or more computer-readable media having computer-readable instructions thereon which, when executed by one or more computers, cause the computers to implement acts of: recording server cluster data during operation of the server cluster, at least some of the server cluster data indicating server resource parameter values; using a load simulation tool that, using the recorded server cluster data, determines a maximum load that can be handled by the server cluster; specifying a load to be handled by the server cluster; and deriving server resource utilization estimates corresponding to the specified load, wherein the using a load simulation tool comprises: creating a test script from the recorded values; running the test script on a master client to simulate load and server resource utilization conditions that existed on a server when the recorded values were recorded; and increasing the load on the server, when the test script is running, until a maximum load that can be handled by the server is obtained, wherein: the server cluster contains a set of identical servers; running the test script run on the master client simulates server cluster operation on only one of the servers of the server cluster; and the method further comprises extrapolating results obtained on the one server using the number of servers in the set of identical servers to obtain the maximum load that can be handled by the server cluster.