command execution in a heterogeneous environment
As a user's computing environment grows from a single time-shared host to a network of specialized and general-purpose machines, the capability for the user to access all of these resources in a consistent and transparent manner becomes desirable. Instead of viewing commands as binary files, we expect the user to view commands as services provided by servers in the network. The user interacts with a personal workstation that locates and executes services on his behalf. Executing a single service provided by any server in the network is useful, but the user would also like to combine services from different machines to perform complex computations. To provide this facility we expand on the UNIX notion of pipes to a generalized pipeline mechanism containing services from a variety of servers. In this paper we explain the merits of a multi-machine pipeline for solving problems of accessing services in a heterogeneous environment. We also give a design and performance evaluation of a general mechanism for multi-machine pipes using the DARPA UDP and TCP protocols.
heterogeneity environments user computation network general access resource consistency transparency service server personality complexity pipeline paper design performance evaluation sharing timing