Performance of a High-Level Parallel Language on a High-Speed Network

• Main Authors: Henri Bal, Raoul Bhoedjang, Rutger Hofman, Ceriel Jacobs, Koen Langendoen, Tim Rühl, Kees Verstoep
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1997
• Subjects: Orca
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.95.1069; http://www.cs.cornell.edu/raoul/papers/jpdc97.pdf

Clusters of workstations are often claimed to be a good platform for parallel processing, especially if a fast network is used to interconnect the workstations. Indeed, high performance can be obtained for low-level message passing primitives on modern networks like ATM and Myrinet. Most application programmers, however, want to use higherlevel communication primitives. Unfortunately, implementing such primitives efficiently on a modern network is a difficult task, because their software overhead is relatively much higher than on a traditional, slow network (such as Ethernet). In this paper we investigate the issues involved in implementing a high-level programming environment on a fast network. We have implemented a portable runtime system for an object-based language (Orca) on a collection of processors connected by a Myrinet network. Many performance optimizations were required in order to let application programmers benefit sufficiently from the faster network. In particular, we have optimized message handling, multicasting, buffer management, fragmentation, marshalling, and various other issues. The paper analyzes the impact of these optimizations on the performance of the basic language primitives as well as parallel applications. Keywords: clusters, threads, communication protocols, multicast, Myrinet, Illinois Fast Messages. 1