Locating resources in computer networks having cache server nodes
First Claim
1. In a computer network which includes a plurality of nodes, two or more of which are cache server nodes which store entries representing the location and characteristics of certain network resources, each of the plurality of nodes either being served by a cache server node or being a cache server node, all nodes served by a particular cache server node being defined as being within the domain of that cache server node, a method of locating a target resource in response to a locate request from one of the nodes, the method being performed at the cache server node which serves the requesting node and comprising the steps of:
- (a) searching resource directories maintained at the cache server node for an acceptable entry defining the location and characteristics of the target resource;
(b) if no acceptable entry is found in the cache server node resource directories, broadcasting the locate request to all nodes within the cache server node'"'"'s domain;
(c) if no acceptable entry is found in the directories of nodes within the cache server node'"'"'s domain, directing the locate request to one or more alternate cache server nodes in the network, said directing step further comprising the steps ofdetermining whether alternate cache server nodes are categorized by levels of capabilities in maintaining resource records,if the alternate cache server nodes are so categorized, directing the locate request to the cache server node determined to have the highest level of capability,if the alternate cache server nodes are not so categorized, then directing the locate request to all of the cache server nodes simultaneously; and
(d) if no acceptable reply is returned from the cache server nodes to which the locate request was directed, then broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource.
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Accused Products
Abstract
A computer network in which resources are dynamically located through the use of LOCATE requests includes multiple cache server nodes, network nodes which have an additional obligation to build and maintain large caches of directory entries. Cache server nodes play a key role in the LOCATE process and can prevent redundant network-wide broadcasts of LOCATE requests. Where an origin cache server node receives a request from a served node, the cache server node searches its local directories first, then forwards the request to alternate cache server nodes if necessary. If the necessary information isn'"'"'t found locally or in alternate cache server nodes, the LOCATE request is then broadcast to all network nodes in the network. If the broadcast results are negative, the request is forwarded to selected gateway nodes to permit the search to continue in adjacent networks.
332 Citations
7 Claims
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1. In a computer network which includes a plurality of nodes, two or more of which are cache server nodes which store entries representing the location and characteristics of certain network resources, each of the plurality of nodes either being served by a cache server node or being a cache server node, all nodes served by a particular cache server node being defined as being within the domain of that cache server node, a method of locating a target resource in response to a locate request from one of the nodes, the method being performed at the cache server node which serves the requesting node and comprising the steps of:
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(a) searching resource directories maintained at the cache server node for an acceptable entry defining the location and characteristics of the target resource; (b) if no acceptable entry is found in the cache server node resource directories, broadcasting the locate request to all nodes within the cache server node'"'"'s domain; (c) if no acceptable entry is found in the directories of nodes within the cache server node'"'"'s domain, directing the locate request to one or more alternate cache server nodes in the network, said directing step further comprising the steps of determining whether alternate cache server nodes are categorized by levels of capabilities in maintaining resource records, if the alternate cache server nodes are so categorized, directing the locate request to the cache server node determined to have the highest level of capability, if the alternate cache server nodes are not so categorized, then directing the locate request to all of the cache server nodes simultaneously; and (d) if no acceptable reply is returned from the cache server nodes to which the locate request was directed, then broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource. - View Dependent Claims (2, 3)
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4. In a computer network which includes a plurality of nodes, two or more of which are cache server nodes which store entries representing the location and characteristics of certain network resources;
- each of the plurality of nodes either being served by a cache server node or being a cache server node, a system for locating a target resource in response to a locate request from one of the nodes, said system being included in the cache server node which serves the requesting node and comprising;
(a) means responsive to the receipt of the locate request to search resource directories maintained at the cache server node for an acceptable entry defining the location and characteristics of the target resource; (b) means responsive to the absence of a suitable entry in the cache server node resource directories to direct the locate request to one or more alternate cache server nodes in the network, said means further comprising means for determining whether one of the alternate cache server nodes is defined as being functionally superior to the other alternate cache server nodes, means responsive to a determination that one of the alternate cache server nodes is defined as functionally superior to direct the locate request to that cache server node, and means responsive in the absence of a defined functionally superior cache server node to direct the locate request to all alternate cache server nodes simultaneously; and (c) means responsive in the absence of an acceptable reply from the alternate cache server nodes to which the locate request was directed for broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource.
- each of the plurality of nodes either being served by a cache server node or being a cache server node, a system for locating a target resource in response to a locate request from one of the nodes, said system being included in the cache server node which serves the requesting node and comprising;
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5. A cache server node for use in a computer network which includes a plurality of nodes, each of which is either served by a cache server node or is a cache server node, each of said cache server nodes storing entries representing the location and characteristics of certain network resources and comprising:
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(a) means responsive to the receipt of allocate request from a requesting node that a specified target resource be located to search resource directories maintained at the cache server node for an acceptable entry defining the location and characteristics of the target resource; (b) means responsive to the absence of an acceptable entry in the cache server node resource directories to direct the locate request to one or more alternate cache server nodes in the network, said means comprising means for determining whether one of the alternate cache server nodes is defined as being functionally superior to the other alternate cache server nodes, means responsive to a determination that one of the alternate cache server nodes is defined as functionally superior to direct the locate request to that cache server node, means responsive in the absence of a defined functionally superior cache server node to direct the locate request to all alternate cache server nodes simultaneously; and (c) means responsive in the absence of an acceptable reply from the alternate cache server nodes for broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource.
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6. In a computer network which includes a plurality of nodes, two or more of which are cache server nodes which store entries representing the location and characteristics of certain network resources, each of the plurality of nodes either being served by a cache server node or being a cache server node, a system for locating a target resource in response to a locate request from one of the nodes, said system being included in the cache server node which serves the requesting node and comprising:
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(a) means responsive to the receipt of the locate request to search resource directories maintained at the cache server node for an acceptable entry defining the location and characteristics of the target resource; (b) means responsive to the absence of a suitable entry in the cache server node resource directories to direct the locate request to one or more alternate cache server nodes in the network, said means further comprising means for determining whether one of the alternate cache server nodes is defined as being functionally superior to the other alternate cache server nodes, means responsive to a determination that one of the alternate cache server nodes is defined as functionally superior to direct the locate request to that cache server node, and means responsive in the absence of a defined functionally superior cache server node to direct the locate request to the alternate cache server nodes in succession until an acceptable reply is received or until the locate request has been directed to all of said alternate cache server nodes; and (c) means responsive in the absence of an acceptable reply from the alternate cache server nodes to which the locate request was directed for broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource.
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7. A cache server node for use in a computer network which includes a plurality of nodes, each of which is either served by a cache server node or is a cache server node, each of said cache server nodes storing entries representing the location and characteristics of certain network resources and comprising:
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(a) means responsive to the receipt of a locate request from a requesting node that a specified target resource be located to search resource directories maintained at the cache server node for tan acceptable entry defining the location and characteristics of the target resource; (b) means responsive to the absence of an acceptable entry in the cache server node resource directories to direct the locate request to one or more alternate cache server nodes in the network, said means comprising means for determining whether one of the alternate cache server nodes is defined as being functionally superior to the other alternate cache server nodes, means responsive to a determination that one of the alternate cache server nodes is defined as functionally superior to direct the locate request to that cache server node, means responsive in the absence of a defined functionally superior cache server node to direct the locate request to the alternate cache server nodes in succession until an acceptable reply is received from one of said alternate cache server nodes or until the locate request has been directed to all of said alternate cache server nodes; and (c) means responsive in the absence of an acceptable reply from the alternate cache server nodes for broadcasting the locate request to all other nodes in the network to determine if any of said nodes include a record of the target resource.
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Specification