Using XOS

There are three inter-related aspects to on-boarding a service into XOS. This section is organized accordingly.

• Modeling Framework: XOS defines a modeling framework, which includes both a modeling language (xproto) and a generative toolchain (xosgenx). The abstractions that define a system's behavior are expressed in xproto, with xosgenx then used to generate code for several elements required to control the system (including an API that serves the set of models that have been loaded into XOS). Service developers typically write one or more xproto models to on-board their service. Platform developers sometimes extend xosgenx to support new target elements.

• Synchronizer Framework: XOS defines a synchronization framework that actuates the XOS data model. This framework is reponsible for driving the underlying components configured into a system (for example, services, access devices) towards the desired state. Service developers typically write a synchronizer to on-board their services.

• Core Models and Policies: An XOS-managed system is defined by a core set of xproto models, plus a set of security policies that govern how various principals can act on those models in a multi-tenant environment. Platform developers typically define and evolve the core models and policies, which effectively establishes the foundation on which all services run and are interconnected into service graphs.