METRICS

Database systems allow quick creation of performance problems. The goal of database systems is to allow the computer-illiterate to write complex and complete applications. It is the job of the system to translate a high-level description of data and ...

Database machine architectures consisting of multiple microprocessors or mini-computers are attracting wide attention. There have been several proposals and prototypes (see, e.g., DeWitt, Gerber, Graefe, Heytens, Kumar and Muralikrishna (1986), Fishman, ...

Repeated studies have shown that a single switching technique, either circuit or packet switching, cannot optimally support a heterogeneous traffic mix composed of voice, video and data. Integrated networks support such heterogeneous traffic by ...

In the past few years, local area networks have come into widespread use for the interconnection of computers. Together with the trend towards digital transmission in voice telephony, this has spurred interest in integrated voice/data networks. The ...

Many virtual circuit service communications networks such as SNA employ virtual circuit transmission method inside the subnet. An essential feature of such networks is that the sequence in which messages are transmitted is maintained throughout the ...

A parallel simulator, PSIMUL, has been used to collect information on the memory access patterns and synchronization overheads of several scientific applications. The parallel simulation method we use is very efficient and it allows us to simulate ...

A variety of disk scheduling algorithms, including some newly defined ones, are compared both in simulation and in tests on a real machine running UNIX^* System V. In the real system tests, first-come first-served (FCFS), shortest seek time first (SSTF), ...

We investigate two schemes for placing data on multiple disks. We show that declustering (spreading each file across several disks) is inherently better than clustering (placing each file on a single disk) due to a number of reasons including ...

Expressions are presented for RPS reconnect delays in three basic cases: single path, multiple path with static reconnect, multiple path with dynamic reconnect. The assumption of homogeneous reconnects, which is introduced in the analysis, is shown to ...

A centralized parallel processing system with job splitting is considered. In such a system, jobs wait in a central queue, which is accessible by all the processors, and are split into independent tasks that can be executed on separate processors. This ...

In multiprocessor architectures, it is frequently necessary to provide parallel communication among a potentially large number of processors and memories. Among the many interconnection schemes that have been proposed and analyzed, shuffle-exchange ...

Our work deals with the analysis of the queueing delays of buffered multistage Banyan networks of multiprocessors. We provide tight upper bounds on the mean delays of the second stage and beyond, in the case of infinite buffers. Our results are ...

Two of the most important parameters of a computer are its processor speed and physical memory size. We study the relationship between these two parameters by experimentally evaluating the intrinsic memory and processor requirements of various ...

Performance is a high-priority consideration when designing concurrent or distributed systems. The process of designing such a system is complicated by two factors: (1) the current state-of-the-art in concurrent system design is very ad hoc — software ...

A technique is described for detecting and diagnosing faults at the processor level in a multiprocessor system. In this method, a process is assigned whenever possible to two processors: the processor that it would normally be assigned to (primary) and ...

Models of discrete systems are often utilized to assist in computer engineering and procurement. The tools for modeling have been traditionally developed using either analytic methods or discrete event simulation. The research presented here explores ...

This paper describes a performance monitoring system, Monit, developed for performance evaluation of parallel systems. Monit uses trace files that are generated during the execution of parallel programs. Monit analyzes these trace files and produces ...

A high-level Petri net model of the software architecture of an experimental MIMD multiprocessor system for Artificial Intelligence applications is derived by direct translation of the code corresponding to the assumed workload. Hardware architectural ...

The same application implemented on different systems will necessarily present different workloads to the systems. Characterizations of workloads intended to represent the same application, but input to models of different systems, must also differ in ...

Queueing network models are effective tools for capacity planning of computer systems. The base of all performance oriented questions is the characterization of the computer system workload. At the capacity planning level the workload is described in ...

In distributed systems the efficiency of the network file system is a key performance issue. Replication of files and directories can enhance file system efficiency, but the choice of replication techniques is crucial. This paper studies a number of ...

Communication systems are undergoing a change in use from stream to request-response or transaction communication. In addition, communication systems are becoming increasingly based on high-speed, low delay, low error rate channels. These changes call ...

We adapt several parallel sorting algorithms (block sorting algorithms) and distributed sorting algorithms for implementation on an Ethernet network with diskless Sun workstations. We argue that the performance of sorting algorithms on local area ...

Expressions are found for the throughput and delay performance of a Tree Conflict Resolution Algorithm that is used in a Local Area Network with carrier sensing (and possibly also collision detection). We assume that Massey's constant size window ...

A class of acknowledgment-based transmission control algorithms is considered. In the finite population case, we claim that algorithms based on backoff functions which increase faster than linearly but slower than exponentially are stable up to full ...

Random-access systems (RAS) for collision-type channels have been studied extensively under the assumption of an infinite population which generates a Poisson arrival process. If the population is finite and if the (practically desirable) free-access ...