Most modern network protocols give adequate support for traditional applications such as file transfer and remote login. Distributed applications, however, have different requirements (e.g., efficient at-most-once remote procedure call even in the face of processor failures). Instead of using ad hoc protocols to meet each of the new requirements, we have designed a new protocol, called the Fast Local Internet Protocol (FLIP), that provides a clean and simple integrated approach to these new requirements. FLIP is an unreliable message protocol that provides both point-to-point communication and multicast communication, and requires almost no network management. Furthermore, by using FLIP we have simplified higher-level protocols such as remote procedure call and group communication, and enhanced support for process migration and security. A prototype implementation of FLIP has been built as part of the new kernel for the Amoeba distributed operating system, and is in daily use. Measurements of its performance are presented.

Abstract Amoeba is a capability‐based distributed operating system designed for high‐performance interactions between clients and servers using the well‐known RPC model. The paper starts out by describing the architecture of the Amoeba system, which is typified by specialized components such as workstations, several services, a processor pool, and gateways that connect other Amoeba systems transparently over wide‐area networks. Next the RPC interface is described. The paper presents performance measurements of the Amoeba RPC on unloaded and loaded systems. The time to perform the simplest RPC between two user processes has been measured to be 1‐4 ms. Compared to SUN 3/50's RPC, Amoeba has one ninth of the delay, and over three times the throughput. Finally we describe the Amoeba file server. The Amoeba file server is so fast that it is limited by the communication bandwidth. To the best of our knowledge this is the fastest file server yet reported in the literature for this class of hardware.

Many portable compilers generate an intermediate code that is subsequently translated into the target machine's assembly language.In this paper a stack-machine-based intermediate code suitable for algebraic languages (e.g., PASCAL, C, FORTRAN) and most byte-addressed mini-and microcomputers is described.A table-driven peephole optimizer that improves this intermediate code is then discussed in detail and compared with other local optimization methods.Measurements show an improvement of about 15 percent, depending on the precise metric used.