Abstract: A technique fulfills service requests in a system of computers that communicate as nodes within a network. The technique involves sending, in response to an initial service request that requests a service provided by a primary server node, a mobile agent from the primary server node to an intermediate node. The mobile agent indicates to the intermediate node that a secondary server node is capable of providing the service. The technique further involves intercepting, at the intermediate node, a subsequent service request sent from a client node to the primary server node, the subsequent service request requesting the service, and sending an instruction from the intermediate node to the secondary server node. The instruction instructs the secondary server node to provide the service. The technique further includes providing, in response to the instruction, the service from the secondary server node to the client node.

Abstract: A technique fulfills service requests in a system of computers that communicate as nodes within a network. The technique involves sending, in response to an initial service request that requests a service provided by a primary server node, a mobile agent from the primary server node to an intermediate node. The mobile agent indicates to the intermediate node that a secondary server node is capable of providing the service. The technique further involves intercepting, at the intermediate node, a subsequent service request sent from a client node to the primary server node, the subsequent service request requesting the service, and sending an instruction from the intermediate node to the secondary server node. The instruction instructs the secondary server node to provide the service. The technique further includes providing, in response to the instruction, the service from the secondary server node to the client node.

Abstract: A technique fulfills service requests in a system of computers that communicate as nodes within a network. The technique involves sending, in response to an initial service request that requests a service provided by a primary server node, a mobile agent from the primary server node to an intermediate node. The mobile agent indicates to the intermediate node that a secondary server node is capable of providing the service. The technique further involves intercepting, at the intermediate node, a subsequent service request sent from a client node to the primary server node, the subsequent service request requesting the service, and sending an instruction from the intermediate node to the secondary server node. The instruction instructs the secondary server node to provide the service. The technique further includes providing, in response to the instruction, the service from the secondary server node to the client node.

Abstract: A redirector device for enabling highly reliable deployment of in line network traffic server (such as a document cache) or processor (such as a network monitoring and management device). In normal operation, the device selectively redirects traffic at a link layer to the traffic server, by type of message received or client address or application, server address or application, adjacent network node address, or other parameters. However, the device also detects failures of the traffic server, and when appropriate, switches line traffic to bypass the server. This implements a fail safety feature for the server in the sense that a failure causes traffic to be forwarded past the server, thereby enabling the network to remain operational.

Abstract: A technique for automatic, transparent, distributed, scalable and robust replication of document copies in a computer network wherein request messages for a particular document follow paths from the clients to a home server that form a routing graph. Client request messages are routed up the graph towards the home server as would normally occur in the absence of caching. However, cache servers are located along the route, and may intercept requests if they can be serviced. In order to be able to service requests in this manner without departing from standard network protocols, the cache server needs to be able to insert a packet filter into the router associated with it, and needs also to proxy for the home server from the perspective of the client. Cache servers cooperate to update cache content by communicating with neighboring caches whenever information is received about invalid cache copies.

Abstract: A technique for automatic, transparent, distributed, scalable and robust caching, prefetching, and replication in a computer network that request messages for a particular document follow paths from the clients to a home server that form a routing graph. Client request messages are routed up the graph towards the home server as would normally occur in the absence of caching. However, cache servers are located along the route, and may intercept requests if they can be serviced. In order to be able to service requests in this manner without departing from standard network protocols, the cache server needs to be able to insert a packet filter into the router associated with it, and needs also to proxy for the home server from the perspective of the client. Cache servers may cooperate to service client requests by caching and discarding documents based on its local load, the load on its neighboring caches, attached communication path load, and on document popularity.