Stability, availability, and response in network file service

A network file system called Multifile is described. It meets response, availability, and stability requirements as primitive functions. Multifile has a high degree of responsiveness because its component parts compete among themselves to service file requests; it has high availability because it maintains multiple copies of files; and it exhibits stable behavior over wise range of system parameters. The responsiveness of Multifile to read requests improves as the number of pages per request rises, implying that read ahead pages can profitably be cached at client sites. The throughput of Multifile improves as the request size increases and as the number of clients increases. As server load increases, the responsiveness of Multifile to read requests is stable in most configurations. The throughput of writes is unstable as the number of pages in the wire request rises, implying that write back pages should not be cached at client sites. The scale of events in file service is dominated by disk activity, so lost message exceptions do not occur frequently enough to affect file service; however, duplicate message exceptions are a factor in performance