Creating self-adaptive service systems with Dysoa

Facing Uncertainty in Web Service Compositions

“…Predefined actions guide adaptations according to known context events (for example, through event-conditionaction -ECA -rules). There are several research works that focus on this dimension [6], [7], [8]. However, predefined adaptation actions for known context events are not enough in the open world where several unknown context events can arise (e.g.…”

“…The composition model and the set of tactic models were The Reconfiguration Engine is implemented with our Modelbased Reconfiguration Engine for Web Services (MoRE-WS) [8]. The Execution Engine was implemented with Apache ODE 6 . Apache ODE was chosen because it offers mature hot-deployment support.…”

“…For example, DySOA [6] offers components for monitoring and reconfiguring Web service-centric systems using models. QoSMOS [21] combines formal specification of quality-of-service (QoS) requirements, model-based QoS evaluation, monitoring and parameter adaptation of the QoS models, and planning and execution of system adaptation.…”

“…This process may become tedious and time-consuming; 2) dynamic adaptations are carried out in the closed world, in which the boundary between system and context is known ahead and unchanging [5]. In this scenario, a set of adaptation actions is predefined for fully foreseen context events [6], [7], [8]. However, in the unpredictable open world, service compositions should react to continuous and unanticipated changes in the context.…”

Dynamic adaptation of service compositions with variability models

“…First, DySOA (Bosloper et al, 2005) is a tool that offers components for monitoring and reconfiguring Web service-centric systems. Even though models are used by these components for context analysis, QoS determination, and variability, these models and their related reconfiguration mechanisms at runtime are not presented in a detailed way.…”