SHReQ: coordinating application level QoS

Abstract

We present SHReQ, a formal framework for specifying systems that handle abstract high-level QoS aspects which are becoming more and more important for service oriented computing. SHReQ combines Synchronised Hyperedge Replacement (SHR) with constraint-semirings. SHR is a (hyper)graph rewriting mechanism for modelling mobility and reconfiguration of systems. The novelty of the approach relies on the synchronisation mechanism which is based on constraint-semirings, algebraic structures that provide both the mathematics for multicriteria QoS and the synchronisation policies underlying the SHR mechanism.

Coordination Via Types in an Event-Based Framework

“…For instance, by relaxing the idempotency of × we get a theory which allows one to count the number of topics, thus leading to a notion of linear types. Finally, the type system described in this paper yields a constraint semiring structure [1] that has been successfully exploited to model QoS aspects of distributed systems [8,12]. We argue that this will allow us to express QoS driven coordination policy within our type system.…”

Strategic Alignment of Business Processes

“…We define the quality of service metrics using constraint semirings (c-semiring) similar to [97] we embed csemiring values into process statements as ranking scales for singular requirements.…”

“…The framework we have chosen is described in [132] where each QoS ranking scheme is placed into a constraint semiring. C-semirings have been used to formalize soft constraint problems [97] and [107] where different tuples in a constraint satisfy the constraint to varying degrees.…”

Long-run cost analysis by approximation of linear operators over dioids

“…Recently, these have been used in the field of Quality of Services [12], in particular with systems modelled by graph rewriting mechanisms [19]. In all these approaches, the ⊕ and ⊗ operators of the constraint semiring are used for combining constraints.…”