Synchrony versus causality in distributed systems

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Given a synchronous system, we study the question whether – or, under which conditions – the behaviour of that system can be realized by a (non-trivially) distributed and hence asynchronous implementation. In this paper, we partially answer this question by examining the role of causality for the implementation of synchrony in two fundamental different formalisms of concurrency, Petri nets and the π-calculus. For both formalisms it turns out that each ‘good’ encoding of synchronous interactions using just asynchronous interactions introduces causal dependencies in the translation

Synchrony versus causality in distributed systems

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Given a synchronous system, we study the question whether – or, under which conditions – the behaviour of that system can be realized by a (non-trivially) distributed and hence asynchronous implementation. In this paper, we partially answer this question by examining the role of causality for the implementation of synchrony in two fundamental different formalisms of concurrency, Petri nets and the π-calculus. For both formalisms it turns out that each ‘good’ encoding of synchronous interactions using just asynchronous interactions introduces causal dependencies in the translation

Relative Expressiveness of Process Calculi with Dynamic Update and Runtime Adaptation

U tezi su razmatrani problemi programskih konstrukata koji podržavaju upravljanje greškama u centru mehanizama koji otkrivaju greške i vraćaju sistem u konzistentno stanje. Teza formalno povezuje programske apstrakcije za rukovanje kompenzacijama i dinamičkog ažuriranja tokom izvršavanja. Analizira se relativna ekspresivnost pomenutih računa. Razvijeno je dvanaest kodiranja, šest procesnih računa za rukovanje kompenzacijama u dva računa za adaptivne procese.The thesis considers problems of programming constructs that support failure handling at the heart of mechanisms that detect failures and bring the system back to a consistent state. We formally connect programming abstractions for compensation handling and runtime adaptation and analyzes the relative expressiveness of these calculi. More concrete, we develop twelve encodings of six process calculi with compensation handling into two calculi of adaptable processes