Implementing Production Quality Client/Server Systenms [Book Reviews]

Abstract

Client/server computing is a term that everyone seems to be using at the moment. In the first chapter, the author very appropriately quotes Humpty Dumpty addressing Alice in Through the Looking Glass: “When I use a word, . . . i t means just what I choose it to mean. . . .” All of computing suffers to some extent from the confusion of terms, and anything involving the integration of computing and communication, such as client/server computing, doubly suffers from this confusion. This book is a very welcome attempt at shedding light on the subject and at trying to explain what is required for cliendserver systems to deliver the quality that information science professionals expect of traditional systems. The book contains a wealth of related material and largely succeeds in explaining and clarifying many of the terms and technologies that pervade the subject. T h e opening sections of the book clearly set the context, firmly relating the purpose of client/ server approaches to the business environment with several quite useful and well developed case studies. These sections clearly identify the implications of following such an approach and flag some technical issues for later consideration. The book weighs the pros and cons concerning the move to clienthemer solutions and discusses accompanying organizational changes such as downsizing. The author considers the cost implications and identifies the pitfalls, but also points to areas where significant financial benefits can arise. The remaining and larger part of the book follows the general introductory discussion with a conventional topic-by-topic treatment, considering the technical issues raised earlier in greater depth. T h e topics considered are very comprehensive. Included are client/ server development tools, networking concepts, graphical user interfaces, objectoriented design and programming, networking standards, and communication subsystems such as Open Systems Interconnection (03) and Internet stacks. Also covered are network operating systems and server operating systems, Inter-networking technologies such as routers and gateways, distributed system technologies such as Structured Query Language (SQL) and remote procedure call (RPC), distributed database systems, distributed systems management, electronic messaging and associated standards, implications for working practices and workgroups, security, and a detailed discussion of actual case studies including mission-critical examples. T h e book concludes with a very helpful glossary and a reasonable bibliography. In general, the list of topics is complete and handled thoroughly with care taken to point out recent and likely future developments and to relate each topic to the most significant stmdards, development groups, or proprietary software systems. There are a few surprising omissions, however-for example, distributed object-system techniques such as Distributed Systems Object Model @SOM) and Common Object Request Broker Architecture (Corba), which are demanding much current attention. Although the author discusses objiect-oriented development techniques in the context of conventional C++ and Smalltalk type objects, she fails to explore the more relevant and exciting developments from groups such as the Object Management Group (OMG), albeit the group and the term ORB (Object Request Broker) is mentioned in passing. This book tries to be all-embracing in two dimensions: It aims at a wide audience, from the corporate executive to the application developer, and it tries to be totally comprehensive in the breadth of topics it covers and the information it contains. For any book to meet the conflicting demands of being a management briefing, technical introduction, developer’s guide, and part technical reference would require a very skilled author to successfully provide the alternative routes through the text to satisfy the v:iried reader demands. Although this book is a very ambitious attempt, it does not totally succeed and is in danger of serving none of its intended readers with total satisfaction. Another stylistic criticism is the,way ideas and topics at different logical levels are sometimes allowed to coalesce, failing to provide the reader with a clear mental model of their relationship. The book‘s 22 chapters convteniently fall into two sections: the first five give an introduction to client/server systems, firmly setting them in business context, and the remaining chapters take the reader through a whole range of technical issues. The information manager would find that the first section provides a good grounding in the field and gives familiarity with the subject, while the second half is perhaps useful as a reference and for its excellent glossary. The professional systems