METRICS

In this paper we describe a practical mathematical formulation and solution of the so-called “File Assignment Problem” (FAP) for computer disks. Our FAP solution has been implemented in a PL/I program known as the Placement Optimization Program (POP). ...

Over the past fifteen years, empirical studies of the reference behavior of a number of database systems have produced seemingly contradictory results. The presence or absence of locality of reference and sequentiality have both been reported (or denied)...

Managing a computer system requires that good performance (e.g., large throughputs, small response times) be maintained in order to meet business objectives. Rarely is performance consistently bad. More frequently, performance is good one day and bad ...

Markov models are widely used for the analysis of availability of computer/communication systems. Realistic models often involve state space cardinalities that are so large that it is impractical to generate the transition rate matrix let alone solve ...

Optimistic make is a version of make that executes the commands necessary to bring targets up-to-date prior to the time the user types a make request. Side effects of these optimistic computations (such as file or screen updates) are concealed until the ...

Threads (“lightweight” processes) have become a common element of new languages and operating systems. This paper examines the performance implications of several data structure and algorithm alternatives for thread management in shared-memory ...

During a bulk data transfer over a high speed network, there is a high probability that the next packet received from the network by the destination host is the next packet in the transfer. An optimistic implementation of a bulk data transfer protocol ...

Trace-driven simulation is an important aid in performance analysis of computer systems. Capturing address traces for these simulations is a difficult problem for single processors and particularly for multicomputers. Even when existing trace methods ...

The speed and efficiency of the memory system is a key limiting factor in the performance of supercomputers. Consequently, one of the major concerns when developing a high-performance code, either manually or automatically, is determining and ...

Execution traces can be significantly compressed using their referencing locality. A simple observation leads to a technique capable of compressing execution traces by an order of magnitude; instruction-only traces are compressed by two orders of ...

We present an evaluation of retransmission strategies over local area networks. Expressions are derived for the expectation and the variance of the transmission time of the go-back-n and the selective repeat protocols in the presence of errors. These ...

When many or all of the recipients of a multicast message respond to the multicast's sender, their responses may overflow the sender's available buffer space. Buffer overflow is a serious, known problem of broadcast-based protocols, and can be ...

Recent advances in fiber optic technology (viz. its promise to provide information-carrying capacity in the Gpbs range over long repeater-free distances) has triggered tremendous activity in the study of unidirectional bus networks (because signal flow ...

RECAL is a new recurrence relation for calculating the partition function and various queue length moments for closed, product form networks. In this paper we discuss a number of the issues involved in the software implementation of RECAL on both ...

The method of moments is used to derive exact analytical solutions for an open priority queueing system with preemption-distance priorities and feedback. Customers enter from outside in a Poisson stream. They can feed back for several times, changing ...

This paper concerns the parallel simulation of queueing network models (QNMs) using the conservative (Chandy-Misra) paradigm. Most empirical studies of conservative parallel simulation have used QNMs as benchmarks. For the most part, these studies ...

We study systems consisting of a number of service cells in tandem, each containing a finite buffer. Several policies governing the operation of such systems are described and compared. These include traditional and novel blocking schemes, with ...

Scientific codes are usually parallelized by partitioning a grid among processors. To achieve top performance it is necessary to partition the grid so as to balance workload and minimize communication/synchronization costs. This problem is particularly ...

As multiprocessors with large numbers of processors become more prevalent, we face the task of developing scheduling algorithms for the multiprogrammed use of such machines. The scheduling decisions must take into account the number of processors ...

In this paper we derive an approximation for the mean response time of a multiple queue system in which shortest queue routing is used. We assume there are Κ identical queues with infinite capacity and service times that are exponentially distributed. ...

The response time is the most visible performance index to users of computer systems. End-users see individual response times, not the average. Therefore the distribution of response times is important in performance evaluation and capacity planning ...

This paper gives a simple, accurate first order asymptotic analysis of the transient and steady state behavior of a network which is closed, not product-form and has multiple classes. One of the two nodes of the network is an infinite server and the ...