Distributed System Testbeds: Experimentation with Distributed Systems: Guest Editor's Introduction

Computer ◽  
1982 ◽  
Vol 15 (10) ◽  
pp. 9-11 ◽  
Author(s):  
Berg
Keyword(s):  
Distributed Systems ◽  
Distributed System

XERIS/APEX

2021 ◽  
Vol 40 (2) ◽  
pp. 65-69
Author(s):  
Richard Wai
Keyword(s):  
Distributed Systems ◽  
Real Time ◽  
Distributed System ◽  
Dynamic Scaling ◽  
Distributed Application ◽  
Heavy Weight ◽  
System Models ◽  
In The Wild ◽  
On Line ◽  
Language Technologies

Modern day cloud native applications have become broadly representative of distributed systems in the wild. However, unlike traditional distributed system models with conceptually static designs, cloud-native systems emphasize dynamic scaling and on-line iteration (CI/CD). Cloud-native systems tend to be architected around a networked collection of distinct programs ("microservices") that can be added, removed, and updated in real-time. Typically, distinct containerized programs constitute individual microservices that then communicate among the larger distributed application through heavy-weight protocols. Common communication stacks exchange JSON or XML objects over HTTP, via TCP/TLS, and incur significant overhead, particularly when using small size message sizes. Additionally, interpreted/JIT/VM-based languages such as Javascript (NodeJS/Deno), Java, and Python are dominant in modern microservice programs. These language technologies, along with the high-overhead messaging, can impose superlinear cost increases (hardware demands) on scale-out, particularly towards hyperscale and/or with latency-sensitive workloads.

Distributed system simulation using infinite product expansions

SIMULATION ◽  
1970 ◽  
Vol 15 (6) ◽  
pp. 255-263 ◽  
Author(s):  
R.E. Goodson
Keyword(s):  
Distributed Systems ◽  
Distributed System ◽  
Transfer Functions ◽  
System Simulation ◽  
Infinite Product ◽  
Characteristic Roots

Infinite product expansions for the transcendental terms in the transfer functions for linear distributed systems are developed. Simulation of the dynamic re sponse of such systems is indicated, using the product expansion. Comparisons are made between the classi cal eigenvalue and product expansion approximations. It is concluded that the product expansion is an ex tremum transient-amplitude-preserving approximation based on the correct characteristic roots.

A THREE-ROUND ADAPTIVE DIAGNOSTIC ALGORITHM IN A DISTRIBUTED SYSTEM MODELED BY DUAL-CUBES

2014 ◽  
Vol 25 (02) ◽  
pp. 125-139 ◽  
Author(s):  
JHENG-CHENG CHEN ◽  
CHIA-JUI LAI ◽  
CHANG-HSIUNG TSAI
Keyword(s):  
Distributed Systems ◽  
Distributed System ◽  
Diagnostic Algorithm ◽  
Building Blocks ◽  
Diagnostic Approach ◽  
Diagnostic Model ◽  
Test Results ◽  
Spanning Subgraph ◽  
Test Result ◽  
Distributed Computer Systems

Problem diagnosis in large distributed computer systems and networks is a challenging task that requires fast and accurate inferences from huge volumes of data. In this paper, the PMC diagnostic model is considered, based on the diagnostic approach of end-to-end probing technology. A probe is a test transaction whose outcome depends on some of the system's components; diagnosis is performed by selecting appropriate probes and analyzing the results. In the PMC model, every computer can execute a probe to test a dedicated system's components. Furthermore, any test result reported by a faulty probe station is unreliable and the test result reported by fault-free probe station is always correct. The aim of the diagnosis is to locate all faulty components in the system based on collection of the test results. A dual-cube DC(n) is an (n + 1)-regular spanning subgraph of a (2n + 1)-dimensional hypercube. It uses n-dimensional hypercubes as building blocks and returns the main desirable properties of the hypercube so that it is suitable as a topology for distributed systems. In this paper, we first show that the diagnosability of DC(n) is n + 1 and then show that adaptive diagnosis is possible using at most 22n+1 + n tests for a 22n+1-node distributed system modeled by dual-cubes DC(n) in which at most n + 1 processes are faulty. Furthermore, we propose an adaptive diagnostic algorithm for the DC(n) and show that it diagnoses the DC(n) in three testing rounds and at most 22n+1 + O(n3) tests, where each node is scheduled for at most one test in each round.

Port-Based Modeling of Distributed-Lumped Parameter Systems

2010 ◽  
Vol 164 ◽  
pp. 183-188
Author(s):  
Cezary Orlikowski ◽  
Rafał Hein
Keyword(s):  
Distributed Systems ◽  
Transfer Function ◽  
Distributed System ◽  
Function Method ◽  
Input Data ◽  
Distributed Parameter ◽  
Transfer Function Method ◽  
Lumped Parameter ◽  
Concise Representation ◽  
Distributed Transfer Function

This paper presents a uniform, port-based approach for modeling of both lumped and distributed parameter systems. Port-based model of the distributed system has been defined by application of bond graph methodology and distributed transfer function method (DTFM). The proposed approach combines versatility of port-based modeling and accuracy of distributed transfer function method. A concise representation of lumped-distributed systems has been obtained. The proposed method of modeling enables to formulate input data for computer analysis by application of DTFM.

Usage of IEC Standards for Distributed Control Systems Modelling

2012 ◽  
Vol 220-223 ◽  
pp. 2672-2677
Author(s):  
Tomas Bezak ◽  
Maximilian Stremy
Keyword(s):  
Distributed Systems ◽  
Control Systems ◽  
Distributed Control ◽  
Distributed System ◽  
Direct Solution ◽  
Distributed Control Systems ◽  
Individual System ◽  
Long Time ◽  
Systems Modelling ◽  
Iec 61499

When creating distributed control systems, we can choose one of two possible approaches based on IEC 61131 and IEC 61499 standards. The first of them has been used for a long time in the PLC sphere, but it does not directly support the creation of extensive distributed systems. The second of the standards, IEC 61499, offers a direct solution for distributed system creation. The truth is that it is a new standard, which is why it is supported by only a few device manufacturers. This raises the question of which approach and which standard is more effective and suitable for individual system designing.

scholarly journals Modelling distributed and channelized subglacial drainage: the spacing of channels

2011 ◽  
Vol 57 (202) ◽  
pp. 302-314 ◽  
Author(s):  
Ian J. Hewitt
Keyword(s):  
Distributed Systems ◽  
Distributed System ◽  
Water Pressure ◽  
Ice Sheet ◽  
Length Scale ◽  
Effective Pressure ◽  
Open Drainage ◽  
Critical Discharge ◽  
Subglacial Drainage

AbstractModels are proposed for channelized and distributed flow of meltwater at the base of an ice sheet. The volumes of both channel and distributed systems evolve according to a competition between processes that open drainage space (e.g. sliding over bedrock, melting of the ice) and processes that close it (e.g. viscous creep of the ice due to a positive effective pressure). Channels are generally predicted to have lower water pressure and therefore capture water from the surrounding regions of distributed flow. There is a natural length scale associated with the distributed system that determines the width of the bed from which water can be drawn into a channel. It is suggested that this determines the spacing between major channels and that this may be reflected in the spacing of eskers. A more permeable distributed system results in more widely spaced, and therefore larger, channels. Calculations of the flow into the head of a channel reveal that there is a critical discharge necessary for it to form, and provide a criterion for where channels can exist.

scholarly journals Communication Analysis of Distributed Programs

2006 ◽  
Vol 14 (2) ◽  
pp. 151-170 ◽  
Author(s):  
Sharon Simmons ◽  
Dennis Edwards ◽  
Phil Kearns
Keyword(s):  
Distributed Systems ◽  
Partial Order ◽  
Distributed System ◽  
Source Code ◽  
Communication Analysis ◽  
Distributed Programs ◽  
Wide Range ◽  
Concurrent Relationships ◽  
Causality Information ◽  
Time Evaluation

Capturing and examining the causal and concurrent relationships of a distributed system is essential to a wide range of distributed systems applications. Many approaches to gathering this information rely on trace files of executions. The information obtained through tracing is limited to those executions observed. We present a methodology that analyzes the source code of the distributed system. Our analysis considers each process's source code and produces a single comprehensive graph of the system's possible behaviors. The graph, termed the partial order graph (POG), uniquely represents each possible partial order of the system. Causal and concurrent relationships can be extracted relative either to a particular partial order, which is synonymous to a single execution, or to a collection of partial orders. The graph provides a means of reasoning about the system in terms of relationships that will definitely occur, may possible occur, and will never occur. Distributed assert statements provide a means to monitor distributed system executions. By constructing thePOGprior to system execution, the causality information provided by thePOGenables run-time evaluation of the assert statement without relying on traces or addition messages.

scholarly journals Node Availability for Distributed Systems considering processor and RAM utilization for Load Balancing

2010 ◽  
Vol 5 (3) ◽  
pp. 336
Author(s):  
Antonio Menendez Leonel de Cervantes ◽  
Hector Benitez Perez
Keyword(s):  
Distributed Systems ◽  
Load Balancing ◽  
Distributed System ◽  
Dynamic Scheduling ◽  
Decision Criterion ◽  
Dynamic Load Balancing ◽  
Other Information ◽  
Node Availability ◽  
Load Balancing Algorithm

<p>Node-Availability is a new metric that based on processor utilization, free RAM and number of processes queued at a node, compares different workload levels of the nodes participating in a distributed system. Dynamic scheduling and Load-Balancing in distributed systems can be achieved through the Node-Availability metric as decision criterion, even without previously knowing the execution time of the processes, nor other information about them such as process communication requirements.<br /> This paper also presents a case study which shows that the metric is feasible to implement in conjunction with a dynamic Load-Balancing algorithm, obtaining an acceptable performance.</p>

scholarly journals Recent innovations in Distributed Systems: Challenges and Benefits

2013 ◽  
Vol 10 (10) ◽  
pp. 2057-2061
Author(s):  
Madhurima Hooda ◽  
Amandeep Kaur ◽  
Madhulika Bhadauria
Keyword(s):  
Distributed Systems ◽  
Distributed System ◽  
World Wide ◽  
Online Shopping ◽  
The Internet ◽  
Web Browser ◽  
The World ◽  
Access Information ◽  
Mobile Computers ◽  
The Web

The World Wide Web is used by millions of people everyday for various purposes including email, reading news, downloading music, online shopping or simply accessing information about anything. Using a standard web browser, the user can access information stored on Web servers situated anywhere on the globe. This gives the illusion that all this information is situated locally on the user’s computer. In reality, the Web represents a huge distributed system that appears as a single resource to the user available at the click of a button. This paper gives an overview of distributed systems in current IT sector. Distributed systems are everywhere. The internet enable users throughout the world to access its services wherever they may be located [1]. Each organization manages an intranet, which provides local services for local users and generally provides services to other users in the internet. Small distributed systems can be constructed from mobile computers and other small computational devices that are attached to a wireless network.

Access Control Frameworks for a Distributed System

2009 ◽  
pp. 254-265
Author(s):  
Rajeev R. Raje ◽  
Alex Crespi ◽  
Omkar J. Tilak ◽  
Andrew M. Olson
Keyword(s):  
Distributed Systems ◽  
Access Control ◽  
Software Development ◽  
Distributed System ◽  
Promising Technique

Component-based software development offers a promising technique for creating distributed systems. It does require a framework for specifying component properties, analyzing the behaviors of a system before composition, and validating them during operation. This chapter focuses on access control properties of a distributed system. It provides a framework that addresses the following issues: (a) specifying access control properties for individual components, (b) identifying components with required access control properties, and (c) formulating compositional models for predicting the access control properties of a composed system from those of its individual components.

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