Patent ID: 7991867

Claim:
An apparatus comprising: one or more processors; and a machine-readable storage medium including instructions executable by the one or more processors for: accessing an operational criterion used to select a sever; identifying, based on the operational criterion, a plurality of servers, such that each server in the plurality of servers meets the operational criterion at a time the server was last contacted; obtaining an IP (Internet Protocol) address of each server in the plurality of servers; constructing a probe packet in which the IP address of the each server in the plurality of servers is listed in an order, a first and a last IP addresses in a list being IP addresses of the apparatus and including, in the probe packet, instructions on processing the probe packet by a server that receives the probe packet; instructing, through a transmission of the probe packet, each server in the list receiving the probe packet to process the instructions included in the probe packet and to send the probe packet to a next server in the list; sending the probe packet to a first server whose IP address is a second IP address in the list of IP addresses in the probe packet, the first server performing an operation based on the instructions included in the probe packet and sending the probe packet to a subsequent server whose IP address is a next address in the list of IP addresses, such that the probe packet is passed through each server whose IP address is in the list of IP addresses, with each server sending an acknowledgement signal to the server it received the probe packet from, and a last server to receive the probe packet sends the probe packet to the apparatus; receiving the acknowledgement signal from the first server and the probe packet from the last server; and determining, based on at least one selected from a group including receiving the acknowledgement signal from the first server and receiving the probe packet from the last server, that all of the servers in the list meet the operational criterion.