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service-oriented architecture (SOA)
service-oriented architecture (SOA)
is a set of principles and methodologies for designing and developingsoftware in the form of interoperable services
SOA generally provides a way for consumers of services, such as web-based applications, to be aware of available SOA-based services. For example, several disparate departments within a company may develop and deploy SOA services in different implementation languages; their respective clients will benefit from a well-defined interface to access them. XMLis often used for interfacing with SOA services, though this is not required. JSON is also becoming increasingly common.
Types of(SOA) :
Four common SOA types have emerged in order to improve physical design.[11]Documenting architecture types encourages services that are more standardized, interoperable and composable. This also assists in understanding interdependencies among services.
Service architecture
This is the physical design of an individual service that encompasses all the resources used by a service. This would normally include databases, software components, legacy systems, identity stores, XML schemas and any backing stores, e.g. shared directories. It is also beneficial to include any service agentsemployed by the service, as any change in these service agents would affect the message processing capabilities of the service.
Service composition architecture
One of the core characteristics of services developed using service-orientationdesign paradigm is that they are composition-centric. Services with this characteristic can potentially address novel requirements by recomposing the same services in different configurations. Service composition architecture is itself a composition of the individual architectures of the participating services. In the light of the Service Abstraction principle, this type of architecture only documents the service contract and any published service-level agreement (SLA); internal details of each service are not included.
If a service composition is a part of another (parent) composition, the parent composition can also be referenced in the child service composition. The design of service composition also includes any alternate paths, such as error conditions, which may introduce new services into the current service composition.
Service inventory architecture
A service inventory is composed of services that automate business processes. It is important to account for the combined processing requirements of all services within the service inventory. Documenting the requirements of services, independently from the business processes that they automate, helps identify processing bottlenecks. The service inventory architecture is documented from the service inventory blueprint, so that service candidates can be redesigned before their implementation.
Service-oriented enterprise architecture
This umbrella architecture incorporates service, composition and inventory architectures and any enterprise-wide technological resources accessed by these architectures e.g. anERP system. This can further be supplemented by including enterprise-wide standards that apply to the aforementioned architecture types. Any segments of the enterprise that are not service-oriented can also be documented in order to consider transformation requirements if a service needs to communicate with the business processes automated by such segments.
