Composition Of RESTful Services Research Articles

Semantic Restful Service Composition Using Task Specification

Existing Web API search engines allow only category-based browsing and keyword- or tag-based searches for RESTful services. In other words, they do not enable the discovery or composition of real-world RESTful services by application developers. This paper outlines a novel scheme, called Transformation–Annotation–Discovery (TAD), which transforms OpenAPI (Swagger) documents related to RESTful services into a graph structure and then automatically annotates the semantic concepts on graph nodes using Latent Dirichlet Allocation (LDA) and WordNet. TAD can then be used for service composition based on the user requirements specified in two modules: a service discovery chain and logical-operation-based composition. The service discovery chain uses the Hungarian algorithm to assess service interface compatibility in order to facilitate the retrieval of services capable of bridging the gap between specified user requirements and the discovered services. The logical-operation-based composition module identifies services that semantically fit the user requirements, based on the structure of the service flow. Those candidate services are then sent to service discovery chains to enable the simultaneous search for potential composition solutions. System prototype and experiment results demonstrate the feasibility and efficacy of the proposed scheme.

QoS aware descriptions for RESTful service composition: security domain

Current research on QoS aware service composition focuses on a WSDL/RPC service paradigm, characterized by a centralized, synchronous, and stateful approach. In this paper, we explore QoS aware RESTful services composition, which is characterized by a decentralized, stateless and hypermedia-driven environment. We focus particularly on the security domain since current security practices on the Web illustrate the differences between both the centralized, function-based approach and the decentralized, hypermedia and resource-based approach. We rely on ReLL (a REST service description) that can be processed by machine-clients in order to interact with RESTful services. Our approach identifies key security domain elements as an ontology. Elements serve to model hypermedia-based, decentralized security descriptions supporting simple and complex interaction such as protocols and callbacks. In this paper, we propose an extension to ReLL that considers security constraints (ReLL-S) and allows a machine-client to interact with secured resources, where security conditions may change dynamically. A case study illustrates our approach.

Control-Flow Patterns for Decentralized RESTful Service Composition

The REST architectural style has attracted a lot of interest from industry due to the nonfunctional properties it contributes to Web-based solutions. SOAP/WSDL-based services, on the other hand, provide tools and methodologies that allow the design and development of software supporting complex service arrangements, enabling complex business processes which make use of well-known control-flow patterns. It is not clear if and how such patterns should be modeled, considering RESTful Web services that comply with the statelessness, uniform interface and hypermedia constraints. In this article, we analyze a set of fundamental control-flow patterns in the context of stateless compositions of RESTful services. We propose a means of enabling their implementation using the HTTP protocol and discuss the impact of our design choices according to key REST architectural principles. We hope to shed new light on the design of basic building blocks for RESTful business processes.