Patent ID: 8190593

Claim:
A computer-implemented method of enabling a user to search for content, comprising: under control of one or more computer systems configured with executable instructions, receiving a search request including a search query and identifying information for at least user associated with the search request; classifying the search request to correspond to a matching node of a hierarchical allocation tree comprising a plurality of nodes, each node having an assigned usage allocation with respect to a type of resource; determining whether the matching node indicates available capacity, within the usage allocation for the matching node, to process the request, the available capacity of the matching node being based at least in part upon periodic notifications provided by each instance of the type of resource available to process received search requests; and when the matching node indicates available capacity: sending the search query in parallel to each of a plurality of partition servers, each partition server configured to execute the search query against a respective portion of a search index; collating search results from each partition server; and providing the collated search results in response to the received search request; and when the matching node does not indicate available capacity: determining whether the matching node is configured to borrow capacity from at least parent node in the hierarchical allocation tree; determining whether at least one parent node from which the matching node is able to borrow capacity indicates available capacity, within a respective usage allocation, to process the request when the matching node is configured to borrow capacity; and sending the search query in parallel to each of a plurality of partition servers for locating search results to return in response to the search request when at least one parent node from which the matching node is able to borrow capacity indicates available capacity.