DISTRIBUTED AND MoBILE CoMPUTING

Distributed and mobile computing

[Name of the Writer]

[Name of the Institution]

Abstract

Distributed snapshots are an important building block for distributed systems, and are useful for constructing efficient checkpointing protocols, among other uses. Direct application of these algorithms to mobile systems is not feasible, however, due to differences in the environment in which mobile systems operate, relative to general distributed systems. This paper presents a distributed snapshot algorithm that is well-suited to mobile systems, which often have limited bandwidth and long latencies, and where the mobile hosts may roam among the different cells within the system. In addition to presenting the protocol itself, we prove its liveness and safety. As was the case for the classical distributed snapshots protocol and distributed systems, we believe that this protocol will be an important building block for mobile systems. Mobile agents have emerged as a very promising approach for eWork and eBussiness. We have developed an extensive mobile agent infrastructure that supports diverse applications in these fields. our infrastructure is built around two basic components: a mobile-agent based framework for distributed database access and the PaCMAn (Parallel Computing with Java Mobile Agents) metacomputer. The major functionality of our database framework includes (a) the ability to dynamically create personalized views for the mobile client, (b) dynamic creation and configuration of Web-based warehouses and (c) dynamic support of mobile transactions. PaCMAn offers the necessary tools for Web-based distributed High Performance Computing (HPC) and distributed data mining. our infrastructure provides the basis for developing eWork applications in many fields. We have utilized it for applications, both wireless and wireline, such as: Electronic commerce, Health Telematics, Teleworking, Distributed Data-mining and Web-based supercomputing.

Table of Contents

Introduction4

Preliminaries6

System Model6

Definitions and Notations9

A Distributed Snapshot Protocol10

Data Structures and Variables10

The CL protocol11

Adaptation to Mobile Systems13

Running Examples15

Protocol Properties17

Mobile Agents for Distributed Information Retrieval19

Mobile Agents for Web Database Access: The DBMS-Agent19

Dynamic Mobile Agents and Task Handlers21

Views for Wireless and Mobile Clients: Mobile Agents as View Holders21

Dynamic Warehouse Infrastructure: Mobile Agents as Warehouse Holders23

Transactional Mobile Agents23

PaCMAn Metacomputer24

PaCMAn as a Model for Purchasing/Trading Computing Cycles25

Data Mining with PaCMAn26

Query Multiple Database Systems26

Conclusions27

References29

Distributed and Mobile Computing

Introduction

Currently we are experiencing tremendous growth in the use of the Internet and the Web. At the same time, we are in the mist of an explosive growth in the use of wireless communications. These two technologies are transforming the way business is contacted. over the past few years, we have been developing a mobile agent infrastructure that supports business functions on both the Internet and the wireless communication environment. our infrastructure is built around two basic components: a mobile-agent based framework for distributed database access and the PaCMAn (Parallel Computing with Java Mobile Agents) metacomputer.

our database framework is based on an extended client/server model and the deployment of mobile agents and provides a new framework for Web-based distributed access to database systems, a fundamental need for eCommerce and virtual enterprises. We have developed a library of database-enabled mobile agents able to support a variety of database functions including: (i) Web database access, ...