The COI Service Framework manages services and information about services. It is deeply interconnected with the Capability Container as hosting environment for services. It associates services with their descriptions and relations with other services. It enables their discovery and subscription.
To call any service in the system the standard service request protocol has to be used. It is implemented by the capability container and blocks until a response or failure occurs, or until it times out.
A service is provided within a running system as a process (set of processes), deployed in a capability container: See also Capability Container Processes.
Figure 1 depicts the internal structure of the Service Framework.
Figure 1. 2940-00006 Service Framework services (OV-2)
The Directory Service is the public registry for operational service instances, available service types, their service interface, and other metadata such as computational resource requirements, and information pertaining to ownership, availability, or references to policies under which it can be invoked.
The information model of services, i.e., their description, is based on the OWL-S information model for services. Note that the specifications and tools related to OWL-S do not necessarily apply.
Figure 2 depicts the Service Registry Domain Model. A service registry stores service definitions, whereas an associated catalog retains metadata describing them. Parts of a service definition are its name, human-readable description, provider, signature and location. This abstract model can be mapped to various implementation technologies. For instance, the signature may contain interface description (e.g., using WSDL for Web Services) and the location could be an URI.
Figure 2. Service Registry Domain Model (OV-7)
Service Discovery is an important part of the Service Integration framework. It includes the set of technologies, protocols, configurations, and repositories that allow an entity to detect the existence of a particular service, its interfaces, interaction patterns, governing contracts, entry points, etc.
Figure 3. Service Discovery Domain Model(OV-7)
See the following technology references: