Patent ID: 8548961

Claim:
A network device, comprising: a transceiver for receiving a plurality of items from one or more client devices over a network; and a processor for enabling actions, the actions comprising: for each item in the plurality of items, performing further actions, including: assigning an expiration time that indicates when an item is to be scheduled for evaluation to detect a possible change to content of the item; when the assigned expiration time is detected to have expired for the item, scheduling the item for evaluation; selecting the item that is scheduled for evaluation; determining a wait time for the selected item that indicates at least a time duration between being scheduled for evaluation and being selected for evaluation; when a possible change to the content of the selected item is determined for the selected item, setting a new expiration time for scheduling for re-evaluating the selected item for another possible change, wherein the new expiration time being set to at least a minimum expiration time; and when it is determined that the selected item fails to include a possible change to the content of the selected item, setting the new expiration time for scheduling for re-evaluating the selected item for another possible change that is based in part on the expiration time of the selected item and a function of the wait time for the selected item, wherein each item having the determined possible change is scheduled for re-evaluation at a higher frequency than each item where the possible change is undetermined.