Nuno Santos,

D – Departamento de Engenharia Informática, Instituto Superior Técnico, Universidade de Lisboa


O Technological advances made possible the appearance of portable devices enabling the breakthrough of highly dynamic mobile networks where nodes may enter and leave the networks arbitrarily. This poses several difficulties to the availability and consistency of data when data sharing is required between the networks nodes. Ensuring data availability and consistency is hard and strongly dependent on the specific application semantics and utilization.

This dissertation presents the design, implementation and evaluation of MobileTrans, a distributed object-oriented middleware system. To cope with the mobility challenges, MobileTrans provides an adaptive transaction abstraction aiding the reliable management of distributed object graphs. Application programmers manipulate objects within transactions as regular C# objects. At execution time, a transaction policy specifies how transactions behave in the presence of connectivity problems. Policies are written in XPLoiT, a XML based language provided by MobileTrans.

The main design issues of MobileTrans are three. First, the transaction model includes special configurable features enabling variable consistency and atomicity degrees, object fetching parameterization, transaction delegation and caching support. Second, the design of XPLoiT and the policy engine enables transactions to behave as specified in the policies. Finally, the API transparently intercepts and manages distributed objects simplifying the programming abstraction.


Date: 2006-Jan-18     Time: 14:00:00     Room: ANFITEATRO PA-3 DO EDÍFICIO DE PÓS-GRADUAÇÃO DO IST

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