Explicit Modeling of Influences, and of Their Absence, in Distributed Systems

Abstract

Specific problems in practical distributed system design arise from incomplete information about the cooperation requirements, up to, or even beyond, the final design stage. Events in components will occur, or they may occur, depending on (local) user decisions. The latter may also not occur, as a result of yet unknown external influences or design faults. Adequate formal modeling tools should allow for distinguishing between such different event types. Our approach for this purpose to be introduced here is the formal model of I-Systems. As a particularly relevant and unique feature, the presence as well as the absence of interactional influences (as part of distributed cooperation requirements) can be explicitly modeled, with no side effects. A non-trivial synchronization problem is modeled incrementally in order to demonstrate both the modeling and analysis capabilities in I-Systems.

Incremental Modeling Under Large-Scale Distributed Interaction

“…The presentation of formal details is out of the scope of this short paper. They can be found in [3,4]. An on-line animation including the examples as well as the example constructions described will be demonstrated at the conference.…”

“…occurrences of phase transitions), as well as the ensuing influence on, or from, other parts. A technical comprehensive presentation of the static structure, the dynamics, and the semantics of I-Systems can be found in [3,4].…”

“…1.b Step 3 (Fig. 1.c Major Result: In general each organizational form of behavior in a part as specified through autonomous decision effects or dutiful steps according to an organizational role can be modeled through the incremental standard construction explained in the example above [3,4].…”