Abstract: Techniques for performing collective compute operations are described. A collective compute operation can be performed in a logical ring of processing ranks formed by a set of rank groups that each contain a number of processing ranks including a primary rank and one or more secondary ranks. At each rank group, a primary rank receives an incoming data slice via an intranode interconnect from a previous primary rank at multiple hops away on the logical ring. A data transfer is performed between the primary rank and each secondary rank of the rank group. An outgoing data slice is then transferred from the primary rank of the rank group to the next primary rank at multiple hops away on the logical ring.

Abstract: Techniques are provided to maintain data coherency for data transfers among data processing devices in a distributed computing environment. A data buffer in each data processing device can be mapped to an address range that is assigned to transactions that allow out-of-order completions, and a message buffer in each data processing device can be mapped to an address range that is assigned to transactions that follow transaction ordering. Thus, a transaction to store a set of data into the data buffer is completed before a transaction to write a synchronization message in the message buffer indicating that the set of data is stored in the data buffer based on the mapping irrespective of the transaction ordering indicated by each transaction.

Abstract: The integrity of transmitted data can be protected by causing that data to be transmitted twice, and calculating protection information (PI) for the data from each transmission. The PI can include information such as a checksum or signature that should have the same value if the data from each transmission is the same. If the PI values are not the same, an error handling procedure can be activated, such as may retry the transmission. For write operations, the data can be transmitted twice from a source to a storage destination, while for read operations, the data can be transmitted to a recipient then sent back from the recipient to the storage device, with PI calculated for each transmission. A component such as a storage processor can perform at least this comparison step. Such approaches can also be used for network transmission or high performance computing.