PobSAM : policy-based managing of actors in self-adaptive systems

In this paper, we present a formal model, named PobSAM (Policy-based Self-Adaptive Model), for modelingself-adaptive systems. In this model, policies are used as a mechanism to direct and adapt the behaviorof self-adaptive systems. A PobSAM model consists of a set of self-managed modules(SMM). An SMMis a collection of autonomous managers and managed actors. Managed actors are dedicated to functionalbehavior while autonomous managers govern the behavior of managed actors by enforcing suitable policies.To adapt SMM behavior in response to changes, policies governing an SMM are adjusted, i.e., dynamicpolicies are used to govern and adapt system behavior. We employ the combination of an algebraic formalismand an actor-based model to specify this model formally. Managers are modeled as meta-actors whosepolicies are described using an algebra. Managed actors are expressed by an actor model. Furthermore, weprovide an operational semantics for PobSAM described using labeled transition systems. Keywords: Adaptive systems; Policy-based Computing; Component-based Design; Algebra; Actor Models.