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Formal models for distributed negotiations

Dr. Roberto Bruni. Computer Science Department University of Pisa.

Abstract:

In the area of concurrent, distributed and mobile languages there is a renewed interest toward models, languages and primitives for coordination. In particular, for largely distributed scenarios like wide area network computing, web programming, and, more generally, global computing, where synchronous communication is unrealistic, the needs of primitives for handling contracts stipulation, distributed agreements, negotiations with nested choice points to be carried out concurrently, causally dependent decisions emerges as a key issue, in most commercial applications, actually running on different platforms and requiring a coordination layer between components that are designed and implemented separately (e.g., e-commerce or on-line auction systems).

Though orchestration can be interpreted as the atomic execution of certain control activities (e.g., in terms of transactions), more generally, the problem is that of committing the results of long distributed decision processes as soon as the participants reach partial agreements (also called contracts or negotiations). The interest of the research is finding some fully distributed models and languages that can provide convenient alternatives to the centralized (transaction) managers that are usually employed in running applications.

The first part of the course (4 hours) will illustrate the main aspects to be taken into account by formal models (e.g., nested commits and abort, isolation, compensation, openness, dynamicity, distribution).

The second part (8 hours) will survey some recent proposals in the literature, based on suitable extensions of Petri nets, process calculi, and commit protocols.

The last part of the course (4 hours) will sketch some ongoing work in combining all the ingredients to define a flexible language for distributed negotiations.

CV of Proposer:

Roberto Bruni isAssistant Professor at the Computer Science Department, University of Pisa. His main research interests are: Concurrent semantics; algebraic models and languages for open, distributed, concurrent systems; coordination models; calculi for mobile processes and processes with name passing; algebraic and coalgebraic specifications; higher order calculi; Petri nets; applied category theory; term and graph rewriting systems; constraint programming. A more detailed curriculum vitae and list of publications can be found at the following address: http://www.di.unipi.it/~bruni/

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