REST Architectural Style Research Articles

Event-driven Architecture and REST Architectural Style: An Exploratory Study on Modularity


 
 
 Event-driven architecture has been widely adopted in the software industry, emerging as an alternative to the development of enterprise applications based on REST architectural style. However, little is known about the effects of event-driven architecture on modularity while enterprise applications evolve. Consequently, practitioners end up adopting it without any empirical evidence about its impacts on essential indicators, including separation of concerns, coupling, cohesion, complexity, and size. This article, therefore, reports an exploratory study comparing event-driven architecture and REST style in terms of modularity. A realistic application was developed using an event-driven architecture and REST through ve evolution scenarios. In each scenario, a feature was added. The generated versions were compared using ten metrics. The initial results suggest that the event-driven architecture improved the separation of concerns, but was outperformed considering the metrics of coupling, cohesion, complexity and size. The findings are encouraging and can be seen as a first step in a more ambitious agenda to empirically evaluate the bene ts of event-driven architecture against the REST architectural style.
 
 

Сравнительный анализ REST и gRPC, используемых в системе мониторинга виртуализированной инфраструктуры коммуникационной сети

The analysis of papers related to data transmission in the microservice architecture is made. A table with the comparison of the gRPC framework and the REST architectural style according to several criteria is given; it shows similarities and differences of the technologies considered. The results are presented as histograms illustrating the difference between the gRPC and REST in the number of requests when small and big data are transferred. The difference in latency while using the gRPC for different transfer types is shown.

CRUDyLeaf: A DSL for Generating Spring Boot REST APIs from Entity CRUD Operations

Abstract Domain-Specific Languages (DSLs) are programming languages designed specifically to express solutions to problems in a particular domain. It is said they foster productivity and quality. In this work we describe CRUDyLeaf, a DSL focused on the generation of Spring Boot REST APIs from entity CRUD operations. Spring Boot is an open source Java-based framework used to implement the REST architecture style. It has gained popularity among developers mainly because it allows to build stand-alone and production ready software applications (avoiding the use of an application server). Through seven proposed stages (domain immersion, golden application implementation, syntax definition, meta model generation, code generator implementation, deployment, and refinement) we describe the development of this DSL. We also exemplify and evaluate the proposed DSL. Our findings suggest a yield automation rate of 32.1 LOC (Lines Of Code) for each LOC written in this DSL, among other observed benefits.

СОВРЕМЕННЫЕ ПОДХОДЫ В BACKEND РАЗРАБОТКЕ НА ПРИМЕРЕ ОНЛАЙН-МАГАЗИНА

The article discusses modern approaches and technologies in the development of server applications using the example of an online store. Methods for solving the main tasks encountered in developing the server part of the client-server application using the rest architectural style are presented. The internal structure and logic of the Spring framework and the Liquibase, Hibernate ORM, Lombock libraries are briefly presented.

Metamorphic Testing of RESTful Web APIs

Web Application Programming Interfaces (APIs) allow systems to interact with each other over the network. Modern Web APIs often adhere to the REST architectural style, being referred to as RESTful Web APIs. RESTful Web APIs are decomposed into multiple resources (e.g., a video in the YouTube API) that clients can manipulate through HTTP interactions. Testing Web APIs is critical but challenging due to the difficulty to assess the correctness of API responses, i.e., the oracle problem. Metamorphic testing alleviates the oracle problem by exploiting relations (so-called metamorphic relations) among multiple executions of the program under test. In this paper, we present a metamorphic testing approach for the detection of faults in RESTful Web APIs. We first propose six abstract relations that capture the shape of many of the metamorphic relations found in RESTful Web APIs, we call these Metamorphic Relation Output Patterns (MROPs). Each MROP can then be instantiated into one or more concrete metamorphic relations. The approach was evaluated using both automatically seeded and real faults in six subject Web APIs. Among other results, we identified 60 metamorphic relations (instances of the proposed MROPs) in the Web APIs of Spotify and YouTube. Each metamorphic relation was implemented using both random and manual test data, running over 4.7K automated tests. As a result, 11 issues were detected (3 in Spotify and 8 in YouTube), 10 of them confirmed by the API developers or reproduced by other users, supporting the effectiveness of the approach.

Semi-automatic derivation of RESTful choreographies from business process choreographies

Enterprises reach out for collaborations with other organizations in order to offer complex products and services to the market. Such collaboration and coordination between different organizations, for a good share, is facilitated by information technology. The BPMN process choreography is a modeling language for specifying the exchange of information and services between different organizations at the business level. Recently, there is a surging use of the REST architectural style for the provisioning of services on the web, but few systematic engineering approach to design their collaboration. In this paper, we address this gap in a comprehensive way by defining a semi-automatic method for the derivation of RESTful choreographies from process choreographies. The method is based on natural language analysis techniques to derive interactions from the textual information in process choreographies. The proposed method is evaluated in terms of effectiveness resulting in the intervention of a web engineer in only about 10% of all generated RESTful interactions.

Active resources concept of computation for enterprise software

Abstract Traditional computational models for enterprise software are still to a great extent centralized. However, rapid growing of modern computation techniques and frameworks causes that contemporary software becomes more and more distributed. Towards development of new complete and coherent solution for distributed enterprise software construction, synthesis of three well-grounded concepts is proposed: Domain-Driven Design technique of software engineering, REST architectural style and actor model of computation. As a result new resources-based framework arises, which after first cases of use seems to be useful and worthy of further research.

Archive WEB API: A web service for the experiment data archive of Wendelstein 7-X

Wendelstein 7-X was built for the research on steady state operation of stellarators. This sets high requirements on the control and data acquisition (CoDaC) system, with the archive database as one of its main components. W7-X Archive database is the storage of all operational and scientific data. It stores raw data as well as processed data and provides a single database for a wide range of components and data types. The Archive WEB API provides a unified access to the archive database by using web service technologies. The API is based on the REST architecture style, using HTTP as the application protocol: the data is represented as a unified signal resource, which can be addressed via a URL. The users can read data in standard formats, like JSON or PNG. In the same way, the WEB API can be used to import new data to ArchiveDB. This paper describes the concepts of the WEB API and the experiences during the first operational phase of W7-X.

From requirements to source code: a Model-Driven Engineering approach for RESTful web services

During the last few years, the REST architectural style has drastically changed the way web services are developed. Due to its transparent resource-oriented model, the RESTful paradigm has been incorporated into several development frameworks that allow rapid development and aspire to automate parts of the development process. However, most of the frameworks lack automation of essential web service functionality, such as authentication or database searching, while the end product is usually not fully compliant to REST. Furthermore, most frameworks rely heavily on domain specific modeling and require developers to be familiar with the employed modeling technologies. In this paper, we present a Model-Driven Engineering (MDE) engine that supports fast design and implementation of web services with advanced functionality. Our engine provides a front-end interface that allows developers to design their envisioned system through software requirements in multimodal formats. Input in the form of textual requirements and graphical storyboards is analyzed using natural language processing techniques and semantics, to semi-automatically construct the input model for the MDE engine. The engine subsequently applies model-to-model transformations to produce a RESTful, ready-to-deploy web service. The procedure is traceable, ensuring that changes in software requirements propagate to the underlying software artefacts and models. Upon assessing our methodology through a case study and measuring the effort reduction of using our tools, we conclude that our system can be effective for the fast design and implementation of web services, while it allows easy wrapping of services that have been engineered with traditional methods to the MDE realm.

Design Patterns and Extensibility of REST API for Networking Applications

REST architectural style has become a prevalent choice for distributed resources, such as the northbound API of software-defined networking (SDN). As services often undergo frequent changes and updates, the corresponding REST APIs need to change and update accordingly. To allow REST APIs to change and evolve without breaking its clients, a REST API can be designed to facilitate hypertext-driven navigation and its related mechanisms to deal with structure changes in the API. This paper addresses the issues in hypertext-driven navigation in REST APIs from three aspects. First, we present REST Chart, a Petri-Net-based REST service description framework and language to design extensible REST APIs, and it is applied to cope with the rapid evolution of SDN northbound APIs. Second, we describe some important design patterns, such as backtracking and generator, within the REST Chart framework to navigate through large scale APIs in the RESTful architecture. Third, we present a client side differential cache mechanism to reduce the overhead of hypertext-driven navigation, addressing a major issue that affects the application of REST API. The proposed approach is applied to applications in SDN, which is integrated with a generalized SDN controller, SOX. The benefits of the proposed approach are verified in different conditions. Experimental results on SDN applications show that on average, the proposed cache mechanism reduces the overhead of using the hypertext-driven REST API by 66%, while fully maintaining the desired flexibility and extensibility of the REST API.

NeoIDL: A Domain Specific Language for Specifying REST Contracts Detailed Design and Extended Evaluation

Service-oriented computing has emerged as an effective approach for integrating business (and systems) that might spread throughout different organizations. A service is a unit of logic modularization that hides implementation details using well-defined contracts. However, existing languages for contract specification in this domain present several limitations. For instance, both WSDL and Swagger use language-independent data formats (XML and JSON) that are not suitable for specifying contracts and often lead to heavyweight specifications. Interface description languages, such as CORBA IDL and Apache Thrift, solve this issue by providing specific languages for contract specifications. Nevertheless, these languages do not target to the REST architectural style and lack support for language extensibility. In this paper we present the design and implementation of NeoIDL, an extensible domain specific language and program generator for writing REST based contracts that are further translated into service’s implementations. In addition, we also present a systematic evaluation of our approach from different perspectives, which involved the implementation of different services using NeoIDL from the domain of Command & Control. In particular, we found initial evidences that shows that NeoIDL can contribute: (i) to bring return on investment with respect to the design and development of NeoIDL, after the implementation of 4 to 7 services; and (ii) to reduce significantly the number of lines of specification when compared to an existing service specification language such as Swagger.

Physical server provision mechanism in cloud computing based on REST architecture style

Physical server provision mechanism in cloud computing based on REST architecture style

RESTful-Based Bi-level Distribution Framework for Context-Based Mobile Web Service Provision

Complex mobile Web services can be provided from the mobile host in a light weight manner by either partial distributing the execution tasks of the server to a stationary device or completely migrate the execution tasks of the service logic to another mobile host. Our approach goes beyond that and allows running more complex services through applying a bi-level distribution of the execution tasks and the service logic to other mobiles. The technology used is based on REST architectural style. An Extended Mobile Host Complex Web service Framework (EMHCF) for providing complex context-based Web services is defined and developed. The set of mechanisms, which are deployed in the EMHCF, depends on the REST characteristics to facilitate service distribution. Verifying the safety properties of the system is carried out analytically based on formal methods. This is complemented with an empirical validation of the correct behavior of the system through proof-of-concept prototype implementation. The running experimental tests examine the best suitable case scenario for partial distribution.

Extracting REST resource models from procedure-oriented service interfaces

During the past decade a number of procedure-oriented protocols and standards have emerged for making service-offering systems available on the Web. The WS-* stack of protocols is the most prevalent example. However, this procedure and message-oriented approach has not aligned with the true potential of the Web's own architectural principles, such as the uniform identification and manipulation of resources, caching, hypermedia, and layering. In this respect, Resource Oriented Architectures based on the REST architectural style, have been proposed as a possible alternative to the operation-based view of service offerings. To date, compiling a REST API for back-end procedure-oriented services is considered as a manual process that requires as input specialized models, such as, service requirements and behavioral models. In this paper, we propose a resource extraction method in which service descriptions are analyzed, using natural language processing techniques and graph transformations, in order to yield a collection of hierarchically organized elements forming REST resources that semantically correspond to the functionality offered by the service. The proposed approach has been applied as a proof of concept with positive results, for the extraction of resource models from a sizable number of procedure-oriented Web Service interfaces that have been obtained from an open service directory.

Architecture Research and Design of Cloud Computing Service Based on REST

Cloud computing deployment model has: IAAS, PAAS, SAAS, and they can provide calls for the clients by web services. REST-style cloud computing architecture represents resource by the URI, and operates resources by standard HTTP methods GET, PUT, POST, DELETE, etc. In this paper, the e-city website as example, using REST methods to architect website, logistics, customer, the pay bank. The architecture fully reflects the REST architectural style is simple and convenient. But REST flaw is that the limited transaction-oriented processing capabilities. In order to solve this problem, WASL (Web Application Description Language) is used to describe the REST API.

Research on Web-Based Elevator Failure Remote Monitoring System

Recently, elevator failure arose frequently, and has been gradually increasing. An elevator failure remote monitoring system is indispensable to enhance security of and maximize the total facilities efficiency. We reuse existing web technologies and standards to design a web-based elevator failure remote monitoring system which is independent of elevator manufacturers own monitors and complies with the REST architectural style to provide a universal API. We also propose nine types of detectable failure and their detection methods.

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.

Panoramic Street-View Exploration using a Multi-Display Mobile Application

In this paper the authors experiment with multi-display mobile applications that can be used in an environment where multiple smart phones are co-located within the same physical space. Utilizing Remote User Interface interaction metaphor and the REST architectural style they propose a solution that follows the Remote Model-View-Controller model, in such a way that client devices do not need to have application specific software pre-installed. The authors demonstrate the system with the Panorama Bricks application, for displaying, in a multi-display expanded view, street-view style mirror-world panoramas, in a synchronized manner. The architecture proves that such enhanced application scenarios are possible to implement even today, utilizing off-the-shelf mobile smart phones. Their evaluations prove that responsiveness levels are high, even in scenarios where multiple objects are overlaid on top of the mirror-world panoramas.

CoAP: An Application Protocol for Billions of Tiny Internet Nodes

The Constrained Application Protocol (CoAP) is a transfer protocol for constrained nodes and networks, such as those that will form the Internet of Things. Much like its older and heavier cousin HTTP, CoAP uses the REST architectural style. Based on UDP and unencumbered by historical baggage, however, CoAP aims to achieve its modest goals with considerably less complexity.

Web API Database Systems for Rapid Web Application Development

Web APIs are offered in many Web sites for Ajax and mashup, but they have been developed independently since no reusable database component has been specifically created for Web applications. In this paper, we propose WapDB, a distributed database management system for the rapid development of Web applications. WapDB is designed on Atom, a set of Web API standards, and provides several of the key features required for Web applications, including efficient access control, an easy extension mechanism, and search and statistics capabilities. By introducing WapDB, developers are freed from the need to implement these features as well as Web API processing. In addition, its design totally follows the REST architectural style, which gives uniformity and scalability to applications. We develop a proof-of-concept application with WapDB, and find that it offers great cost effectiveness with no significant impact on performance; in our experiments, the development cost is reduced to less than half with the overhead (in use) of response times of just a few msec.