METRICS

Using a simulation model, experiments were conducted on various directory organization schemes and their performance implications. In particular we tested the effects of a multiprogrammed environment on system throughput for retrieval operations. ...

The problem of allocating files in a computer network is a complex combinatorial problem due to the number of integer design parameters involved. These parameters include system cost, number of copies of each file to be stored, and sites at which the ...

This paper discusses the modelling of DB/DC systems operating in a demand paging environment. As an extension of an earlier definition of Denning a class of systems is defined, those operating with “working set integrity”, for which one can obtain ...

In this paper, we study several probabilistic models of inverted file information retrieval systems. In particular, the portion of the system which performs the tasks of list accessing and merging is modeled. The average response times of the system for ...

The purpose of the present paper is to study systems in which different job types are present at the various servers and are processed according to a variety of scheduling disciplines, in particular in “first-come, first-served” order. Our approach is ...

Beginning in mid-1974, the Data Management Center of the Office of the Secretary of the Department of Health, Education, and Welfare undertook to validate an analytic model of computer performance in the context of a large multiprogrammed configuration ...

The paper presents an analytic performance model of a multiprogrammed batch and timeshared context swapped system. The model predicts resource utilizations, batch throughput and timesharing response times as functions of the system hardware ...

Digital Equipment Corporation has recently developed a new PDP-11 operating system called IAS—Interactive Application System. Since the system was to be significantly different from existing PDP-11 systems, customers and DEC field personnel had little ...

Previous studies have shown that a program's behavior can be characterized as a sequence of transitions between phases of execution during which some subset of the program's segments is referenced. The nature of the phases (sometimes called localities ...

Hardware monitoring has proven to be a useful means for measuring the performance of computer systems generally, and is particularly attractive for use on real-time systems due to its attribute of non-interference with system operation. This technique ...

A class of schedules in the two customer central server queueing model, consisting of a “CPU” server and m “I/O” servers, is considered. Optimal (maximal CPU utilization) CPU and I/O schedules are obtained. The best CPU schedule depends on the I/O ...

Research into queuing networks and their applications to computer systems is in a state of prosperity. The object of this paper is to discuss the computational aspect of separable queuing networks. Separable networks constitute that class of models for ...

We develop a method based on diffusion approximations in order to compute, under some general conditions, the queue length distribution for a queue in a network. Applications to computer networks and to time-sharing systems are presented.

Emulation of systems makes it possible to combine the predictive power of simulation with the advantages of measurement carried under a real system workload. An emulator is a microprogrammed implementation of the basic hardware machine. It can be easily ...

This study was performed on a CDC-6600 computer having 500K of Extended Core Storage (ECS), twenty Peripheral Processor Units (PPU's) and twenty-four I/O channels, as shown in Figure I-1. The CPU can load, store, and execute from the 131K of 1 ...

In recent years the use of instruction mixes to define measures of relative computational power has diminished. This paper will describe how a systemic functional mix of much greater power and complexity than the traditional Gibson Mix was derived, then ...

The Test Support Program (TSP) is a real-time interactive computer-based simulation model that provides the environment for testing and verifying the operation of netted air control systems. It provides computer-to-computer simulation of data link ...

This paper defines and determines a graph model of a computer system in a form applicable to system performance analysis. The power of this modeling technique with respect to comprehensibility, accuracy of representation and ease of validation and ...

This paper reports on a measurement study of the Scheduler in the PDP-10 TENEX Operating System under normal loads in a Computer Science research environment at Case Western Reserve University.

A complete description of the methodology and the results ...

A framework for the study of computer capacity is given by means of a definition of capacity in terms of speeds of various parts of a computer as well as memory size. In addition to these machine parameters, we also include certain parameters of the ...

A number of laws are derived which establish relationships between throughput, response time, device utilization, space-time products and various other factors related to computer system performance. These laws are obtained by using the operational ...

In this paper, we shall use the same analytical model to investigate the behaviour of the paging drum when the degree of multiprogramming is set to its optimal value. The main conclusion, which corroborates the general feeling on performance of virtual ...

Balancing interpagefault lifetime (L) against page swap time (S) has always been a performance criterion of great intuitive appeal. This paper shows that, under normal conditions, controlling the memory policy parameter to enforce the constraint L ≥ S, ...

We consider packet-switching network as a queueing system with constant service times: that means that the lengths of the packets are equal. We study such a network by isolating a particular path, that we consider as a tandem system of queueing. Two ...

Access control to shared files in a distributed computing environment requires an efficient method of allocating file resources with local and remote user processes. While software controlled access methods are convenient from the user's point of view, ...

In an Australian national batch-oriented computer network, processing strategies have been investigated, using simulation, to give guidelines for management of the work load and to provide direction for measurement of the performance of the system under ...

This paper examines minimum memory wastage strategies for partitioning and allocating main memory to a stream of jobs, in a context where each job resides throughout its execution in a frame to which it is assigned.

In contrast to usual approaches, the ...

A relatively high level analytical model for computer systems serving both batch and interactive users is presented. The model is unusual in its employment of an endogenous priority scheme to represent a class of strategies for controlling service to ...

It is desired to find the values of certain system parameters which maximize some performance criterion. Using standard experimental design techniques, one runs an initial set of experiments which explore the system's response surface. Subsequently, the ...

In this paper we shall generalize Graham's result so as to include a parameter characterizing the number of tasks assigned to processors by the LPT rule. The new result will show that the worst-case performance bound for LPT sequencing approaches unity ...