Low Latency Workstation Cluster Communications Using Sender Based Protocols

The use of workstations on a local area network to form scalable multicomputers has become quite common A serious performance bottleneck in such carpet clusters is the communication protocol that is used to send data between nodes We report on the design and implementation of a class of communication protocols known as sender based in which the sender speci es the locations at which messages are placed in the receiver s address space The protocols are shown to deliver near link latency and near link bandwidth using Medusa FDDI controllers within the BSD and HP UX operating systems The protocols are also shown to be exible and powerful enough to support common distributed programming models including but not limited to RPC while maintaining expected standards of system and application security and integrity This work was supported by a grant from Hewlett Packard and by the Space and Naval Warfare Systems Command SPAWAR and Advanced Research Projects Agency ARPA Communication and Memory Architectures for Scalable Parallel Computing ARPA order B under SPAWAR contract N C