What is a parallel virtual machine?

A parallel virtual machine is a software application that allows multiple independent computers, geographically spread to each other as a network and borrow the performance and memory of system processing into one application.

Shifting in production costs and popularity of the home computer has led to increasing the availability of highly powerful computers on the consumer market. These machines are insufficiently used by their standard software applications and leave a lot of free processing. The Parallel Virtual Machine software allows these resources to be connected and accessible to solve large, complex scientific, medical or industrial problems.

The parallel virtual machine was first created in 1989 in Oak Ridge National Labs by Al Geist. On the basis of work there the project was extended to the University of Tennessee in March 1991 and has grown since then.

The virtual machine parallel system has two parts, an application that sits unnecessary machines and a routin interface library. Software andThe plication is called Parallel Virtual Machine Daemon, PVMD3 or PMVD. This small program sits passively until it is necessary to start the parallel application of the virtual machine. When a user wants to run this type of program, he must first run a parallel virtual computer. This allows them to access software on any other host.

The

Library of the routine library with a parallel virtual machine contains all the complete list of all codes necessary to coordinate the various tasks that are performed on separate hosts. This library includes standard messaging routines, task coordination, and any change in the virtual computer itself.

The basic concept behind the parallel virtual machine is that any application has several tasks that can be triggered independently. This type of logic is very common is complex scientific calculations. Two are used in parallel virtual machinesModels; Functional and data parallelisms.

functional parallelisms separate the application on clearly defined independent tasks. These tasks are carried out on separate host machines. The parallel virtual machine is used for coordination based on functions such as input, solution, output and display.

Data Parallelism or Single Program Multiple Data (SPMD) is a more popular method. In this method, all tasks are the same, but each host solves a small piece of larger puzzles. The virtual machine parallel environment supports both methods, which is important because it may be the most effective to mix these two methods depending on the required calculations.

C, C ++ and Fortran are computer programming languages ​​used on a parallel virtual computer. These languages ​​were selected because most applications used in this environment were built in these languages. Source code for parallel virtualSoftware for machine is widely available on the Internet and is available via FTP, www,Xnetlib or automatic e -mail.