Applying Mobile Code To Distributed Systems

Applying Mobile Code to Distributed Systems

Abstract: "Use of mobile code can make distributed systems and the abstractions they provide more flexible to build and use. Richer functionality can be given to the interaction between processes by allowing code to be sent between them. More convenient, application-level operations can be made over a network. By making higher order language features transmissible, distributed components can be tightly bound together when they communicate. At the same time, familiar distributed systems can be built using mobile code. Mobile code can make distributed systems adaptable to application needs. Rather than fixing the interface to a resource and the pattern of interaction with it, a minimal interface can be defined and code implementing higher-level interfaces placed alongside it as and when required. These higher-level interfaces can be application-specific, allowing for interaction patterns that were unknown at the time the resource was made available. Sending code close to a resource can also reduce network usage because the point of interaction with it moves. The combination of document markup supporting hypertext and a language supporting state-saving allows for stateful client-server sessions with stateless servers and lightweight clients. Putting dormant mobile code in documents provides an alternative to holding knowledge of application functionality on a server machine or running arbitrary code on a client machine. Mobile code helps to support user mobility. Personalised environments that support state-saving can follow a user between computers. Heterogeneous state-saving allows a user's programs to be relocated between computers. By using a mobile code system with language support for state-saving, applications can direct arbitrary component migration without priming program servers with specific support. In summary, this dissertation supports the thesis that mobile code can be used to enhance distributed systems."

Java in Distributed Systems

Large and complex software systems, such as Internet applications, depend on distributed applications. Although Java has helped reduce the complexity of distributed systems, developers still have to contend with diverse hardware platforms, remote communication over networks, and system failures. Java in Distributed Systems provides a comprehensive guide for anyone wishing to deepen their knowledge of Java in distributed applications. Beginning with a tutorial guide to distributed programming in the Java environment, it shows you how building blocks from threads to Jini can help you to fulfil Sun's vision, that 'the Network is the Computer'. It then goes on to focus on aspects that are still challenging researchers such as concurrency, distribution, and persistence. Key Features: - One of the few books to focus specifically on Java for building distributed applications - Coverage includes threads & sockets, RMI, CORBA, Voyager, Mobile agents, JDBC, object-oriented databases, Java spaces and Jini - Includes advanced chapters on the cutting edge of Java language development, including the author's own proposed Dejay (Distributed Java), an open-source project that offers a unified approach to concurrency, distribution and persistence

Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards