NOW: Orchestrating services in a nomadic network using a dedicated workflow language

Orchestrating services in nomadic or mobile ad hoc networks is not without a challenge, since these environments are built upon volatile connections. Services residing on mobile devices are exposed to (temporary) network failures, which must be considered the rule rather than the exception. This paper proposes a dedicated workflow language built on top of an ambient-oriented programming language that supports dynamic service discovery and communication primitives resilient to network failures. The proposed workflow language, NOW, has support for high level workflow abstractions for control flow, rich network and service failure detection, and failure handling through compensating actions, and dynamic data flow between the services in the environment. By adding this extra layer of abstraction, the application programmer is offered a flexible way to develop applications for nomadic networks.

► NOW is a workflow language for orchestrating services in a nomadic network.
► It supports control flow patterns on top of an ambient-oriented programming language.
► NOW uses a dynamic data passing mechanism with merging strategies.
► We included support for both automatic and user-controlled failure handling.
► The performance scales well over an increasing number of services.