Shared memory performance of multi-computer terminals in distributed information systems

摘要

Use of display and picture-phone terminals will become very common in the near future in distributed information systems. A system model is presented for transmission of input data which is coming from the terminals of users in a limited user resource-sharing environment. The system is assumed to be receiving a mixture of picture-phone terminal data having uniformly distributed inter-arrival times and display terminal data having geometrically-distributed length and Poisson-distributed arrivals. With this type of input data, the performance of a mini/microcomputer with a large memory is analyzed with constant service times, synchronous transmission and single server interruptions through a first-order Markov process. A closed form expression for the input data arrivals is derived. A simple solution to find the memory content probability, and a simple and closed form expression for average queueing delay experienced by the input data is presented. The memory performance is studied and some of the computed values are graphically portrayed to help as guidelines for study of the delay performance of user terminals in a distributed information system.