Patent ID: 8826274

Claim:
A virtual computer system comprising: a network device coupled to a client computer; server computers, each coupled to the network device, to provide services to the client computer; and a performance degradation source locator apparatus coupled to the network device and the server computers, wherein each of the server computers comprises: a processor for computing; a storage unit for storing information; a network interface coupled to the network device; a virtualization module for virtualizing physical resources of the server computer; and a plurality of virtual machines allowing operating systems and applications for providing the services to run on the virtualized physical resources, wherein the network device receives a processing request from the client computer, transfers the processing request to one of the virtual machines, receives a processing response to the processing request from the virtual machine that receives the processing request, and transfers the processing response to the client computer, wherein the network device comprises a latency monitoring module that monitors latency between the receipt time of the processing request and the transfer time of the processing response, and sends, to the performance degradation source locater apparatus, a delay notice indicating that the latency has increased, if the latency has exceeded a predetermined threshold value, and wherein the performance degradation source locater apparatus comprises: communication flow information for setting associations among Internet Protocol (IP) addresses assigned to the virtual machines, identifiers of the server computers, and identifiers of the virtual machines, the communication flow information being a part of information to be transmitted and received by the network device; shared resource information for determining computer resources shared by the virtual machines, the computer resources being computer resources of the server computers and computer resources coupled to the server computers; a delay locater module that refers to the communication flow information to locate the virtual machine and server computer that has caused the delay, upon receipt of the delay notice from the network device; an information collection range determination module that refers to the shared resource information to extract other virtual machines and server computers that share computer resources with the virtual machine that has caused the delay; and a source locator module that obtains performance information on physical computer resources and virtual computer resources of the extracted virtual machines and server computers and the virtual machine and server computer that has caused the delay to determine a virtual machine that has caused the delay.