  Following previous work on the automated deployment orchestration of
component based applications, where orchestrations are expressed in terms of
behaviours satisfying component interface functional dependences, we develop a
formal model specifically tailored for microservice architectures. The first
result that we obtain is decidability of the problem of synthesizing optimal
deployment orchestrations for microservice architectures, a problem that is,
instead, undecidable for generic component-based applications. We, thus, show
how optimal deployment orchestrations can be synthesized and how, by using such
orchestrations we can devise a procedure for run-time adaptation based on
performing global reconfigurations. Finally, we evaluate the applicability of
our approach on a realistic microservice architecture taken from the
literature. In particular, we use the high-level object-oriented probabilistic
and timed process algebra Abstract Behavioural Specification (ABS) to model
such a case study and to simulate it. The results of simulation show the
advantages of global reconfiguration w.r.t. local adaptation.
