Fault tolerant shared system resource with communications passthrough providing high availability communications

Abstract

A communications passthrough mechanism for high availability network communications between a shared system resource and clients of the system resource. The system resource includes a control/processing sub-system including multiple peer blade processors. A port of each blade processor is connected to each client/server network path and each client is connected to a corresponding port of each blade processor. Each blade processor includes a network fault detector exchanging beacon transmissions with other blade processors through corresponding blade processor ports and network paths. Each blade processor includes response generator responsive to a failure to receive a beacon transmission from a failed port of an other blade processor for redirecting the client communications to the failed port on the other blade processor to the corresponding port of the blade processor. A path manager in the blade processor is responsive to operation of the response generator for modifying the communications routing table to correspond with the redirection message to route the client communications to the failed port of the other blade processor to the other blade processor through the inter-processor communications link. Each blade processor may also include an inter-blade communications monitor for detecting a failure in the inter-processor communications link between the blade processor and another blade processor, reading the communications routing table to select a functional network communications path to a port of the other blade processor, and modifying the communications routing table to redirect inter-processor communications to the selected functional network communications path.