Patent ID: 7523178

Claim:
A method of tolerating a failure in an environment in which a plurality of traffic management systems are co-ordinated to manage the supply of web site data from a plurality of servers to a significantly large number of browsing clients via a plurality of network addresses, wherein each of said functional traffic management systems is responsible for at least one network address; each of said functional traffic management systems periodically transmits a signal to each of the other traffic management systems to confirm that it is functioning functionality; each of said traffic management systems individually creates and maintains configuration data that specifies the responsibility of traffic management systems for network addresses dependent upon the status of each of the traffic management systems, such that each traffic management system has local information telling it which of the available servers to use for any combination of available traffic management systems; and each of said traffic management systems responds to a failure of any of the other of said traffic management systems by each taking responsibility for a certain proportion of the network addresses as prescribed by said configuration data, such that functioning traffic management systems take over the responsibility of the network addresses that were the responsibility of the now non-functional traffic management system without receiving additional instructions from a master control; wherein said step of producing an ordered list for an IP address comprises the steps of: identifying a score for each of said traffic management systems by counting the number of IP addresses it has been allocated to as primary system; producing a list of traffic management systems wherein the list is sorted by: (a) said scores, lowest first, and (b) the names of said traffic management systems, in alphabetical order; and placing said primary system at the front of the list; wherein said list is additionally sorted such that traffic management systems having the same score as the primary system and with a name coming alphabetically after the name of said primary system are earlier in the list than traffic management systems with the same score as the primary system and with a name coming alphabetically before the name of said primary system.