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The advent of high bandwidth fibre optic links that may be used over very large distances has lead to much research and development in the field of wide area gigabit networking. One problem that needs to be addressed is how loosely coupled distributed systems may be built over these links, allowing many computers worldwide to take part in complex calculations in order to solve "Grand Challenge" problems. The research conducted as part of this PhD has looked at the practicality of implementing a communication mechanism proposed by Craig Partridge called Late-binding Remote Procedure Calls (LbRPC). LbRPC is intended to export both code and data over the network to remote machines for evaluation, as opposed to traditional RPC mechanisms that only send parameters to pre-existing remote procedures. The ability to send code as well as data means that LbRPC requests can overcome one of the biggest problems in Wide Area Distributed Computer Systems (WADCS): the fixed latency due to the speed of light. As machines get faster, the fixed multi-millisecond round trip delay equates to ever increasing numbers of CPU cycles. For a WADCS to be efficient, programs should minimise the number of network transits they incur. By allowing the application programmer to export arbitrary code to the remote machine, this may be achieved. This research has looked at the feasibility of supporting secure exportation of arbitrary code and data in heterogeneous, loosely coupled, distributed computing environments. It has investigated techniques for making placement decisions for the code in cases where there are a large number of widely dispersed remote servers that could be used. The latter has resulted in the development of a novel prototype LbRPC using multicast IP for implicit placement and a sequenced, multi-packet saturation multicast transport protocol. These prototypes show that it is possible to export code and data to multiple remote hosts, thereby removing the need to perform complex and error prone explicit process placement decisions.

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Orientador: Eleri Cardozo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T04:04:30Z (GMT). No. of bitstreams: 1 Gomes_WanderEuclidesCarneiroPimentel_M.pdf: 357644 bytes, checksum: 6f95a222f32c2fedcd60b534ac8c8f8d (MD5) Previous issue date: 2005 / Resumo: Este trabalho apresenta uma infra-estrutura para auxílio ao desenvolvimento de software baseado em componentes para dispositivos móveis com baixo poder de processamento e armazenamento. Esta infra-estrutura baseia-se em um modelo de componentes neutro em termos de tecnologia e especificado inteiramente em UML (Unified Modeling Language). A plataforma utiliza Web Services para comunicação síncrona entre os componentes. Um Serviço de Notificação baseado em documentos XML (Extensible Markup Language) foi desenvolvido para suporte a notificação assíncrona entre componentes. Um exemplo de aplicação na área de gerência de redes ilustra as funcionalidades da infra-estrutura / Abstract: This work presents an infrastructure for supporting component-based software development for mobile devices with limited resources regarding processing power and storage. This infrastructure is based on a neutral component model in terms of technology and specified entirely in UML (Unified Modeling Language). The platform employs Web Services for synchronous communication between components. A Notification Service based on XML (Extensible Markup Language) documents was developed in order to support asynchronous communication among the components. An example of application in the field of network management illustrates the functionalities of the infrastructure / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica