Measuring User Characteristics on the MILTICS System

Abstract

One of the problems in measuring the performance of a computer system is in defining its normal workload. In the case of timesharing systems, it is necessary to develop a behavioral model of the average user. This thesis presents a study of several parameter that characterize user behavior on the Multics timesharing system at MIT. Data was gathered by monitoring the logon sessions of three different groups of users. The results are presented and comparisons are made between the command usage of the groups. Some patterns of usage do appear in the results, but it is unclear if they can be applied in other situations. A probability distribution of the think time between commands is shown and compared with other distributions. The benchmark program currently used on the Multics system is also compared with the user model described in this study. The capability to monitor user behavior and characteristics is shown to be useful and worth installing in the system.