Abstract: A method and system for transferring noncontiguous messages group including assembling a set of data into a series of transmission packets, packaging a description of the layout of the transmission packets into description packets and then places each description packet into a local buffer while maintaining a count of the number of description packets, transfers each description packet into a transmit buffer for transmission to at least one receiving node, identifies the data packets, and forwards each data packet to the transmit buffer for transmission to the at least one receiving node. The receiving node receives the transmission packets, identifies each packet as a description packet or data packet, places the description packets in a local buffer for storage until the description is complete, places each description packet into a user data buffer, stores data packets in a local queue until the description is complete, then transfers the data packets to the user buffer.

Abstract: In a multinode data processing system in which nodes exchange information over a network or through a switch, a structure and mechanism are provided which enables data packets to be sent and received in any order. Normally, if in-order transmission and receipt are required, then transmission over a single path is essential to insure proper reassembly. However, the present mechanism avoids this necessity and permits Remote Direct Memory Access (RDMA) operations to be carried out simultaneously over multiple paths. This provides a data striping mode of operation in which data transfers can be carried out much faster since packets of single or multiple RDMA messages can be portioned and transferred over several paths simultaneously, thus providing the ability to utilize the full system bandwidth that is available.

Abstract: A protocol interface is provided for an active message protocol of a computing environment and a client process employing the active message protocol. The protocol interface includes an interface to a header handler function associated with the client process. The interface to the header handler function has parameters to be passed by and a parameter to be returned to the active message protocol when processing a message received through the active message protocol. The parameters to be passed include current message state information and current message type information for the received message. These parameters facilitate message-specific decisions by the header handler function about processing data of the message by the active message protocol. The parameter to be returned to the active message protocol instructs the active message protocol how to process the received message other than just where to store the message.

Abstract: Lock-free queues of a shared memory environment are used to facilitate communication within that environment. The lock-free queues can be used for interprocess communication, as well as intraprocess communication. The lock-free queues are structured to minimize the use of atomic operations when performing operations on the queues, and to minimize the number of enqueue/dequeue operations to be performed on the queues.

Abstract: Epoch numbers are maintained in a pair wise fashion at a plurality of communication endpoints to provide communication consistency and recovery from a range of failure conditions including total or partial node failure and subsequent recovery. Once an epoch state inconsistency is recognized, negotiation procedures provide an effective mechanism to reestablish valid communication links without the need to employ global variables which inherently possess greater transmission and overhead requirements needed to maintain communications. Renegotiation of recognizably valid epoch numbers occurs on a pair wise basis.

Abstract: Globally consistent information is locally provided to communications layers. Globally consistent information is stored in a Network Availability Matrix, which is locally accessible by a communications layer. If an event is detected, the communications layer is automatically notified by the Network Availability Matrix, and is able to use the information in the Network Availability Matrix to quickly take action.

Abstract: The invention is a replication method that requires only one copy of a packet entering a multiport switch to be transmitted from the input port, the method acquiring the deadlock avoidance advantages of virtual cut-through operation. The goal is achieved via a central buffer, with replication occurring during the read of the chunk out of the central buffer by the output ports.