Patent ID: 7761594

Claim:
A caching device to operate as an intermediary node on a network, the device comprising: a cache to store content requestable by a client on the network; a user interface to enable a user to specify a set of forwarding rules for forwarding requests on the network; a database to store the set of forwarding rules; a request processing unit to receive a request from the client; a rule evaluator to evaluate the set of forwarding rules to identify within the set of forwarding rules a rule which applies to the request, such that the request processing unit attempts to forward the request to a destination selected according to said rule, wherein the rule indicates a host in a defined forwarding hierarchy; and a rule engine to determine an availability of the host indicated in said rule and, when the host is available, to select the host as a forwarding destination and to cause the request processing unit to forward the request to the host according to said rule, wherein the request processing unit is further to use a timeout period in attempting to establish a connection with the forwarding destination, the timeout period based on information indicative of a responsiveness of the forwarding destination, wherein the information indicative of the responsiveness of the forwarding destination comprises information indicative of a loading on, or a response time of, the forwarding destination, and wherein the timeout period is computed in response to the request being received, wherein, when the request processor is unable to forward the request according to said rule, the rule evaluator resumes evaluating the set of forwarding rules to identify another rule corresponding to the request.