Re(vi)viendo Cabo de Gata: entropía a la deriva

En 2010 realicé una deriva por el Parque Natural de Cabo de Gata con la intención de captar a través de la fotografía y el vídeo las sensaciones que un entorno manipulado por el hombre produciría sobre el viajero. La posterior elaboración de este material dio como resultado el proyecto ‘(VI)VIENDO’. Esta experiencia, de eminente carácter práctico-artístico, careció en su día de un trasfondo teórico escrito que lo apoyase. Con objeto de enmendar esta salvedad, se pretende redescubrir este proceso creativo desde la deriva situacionista y el concepto de entropía artística promulgado por Robert Smithson en 1967. El objetivo del presente artículo es poner de manifiesto la utilidad de la deriva como metodología investigadora del territorio en permanente renovación así como sostener un concepto de belleza alternativo que solo es perceptible una vez que hemos sido capaces de transgredir la estética

Automating SLA-Driven API Development with SLA4OAI

The OpenAPI Specification (OAS) is the de facto standard to describe RESTful APIs from a functional perspective. OAS has been a success due to its simple model and the wide ecosystem of tools supporting the SLA-Driven API development lifecycle. Unfortunately, the current OAS scope ignores crucial information for an API such as its Service Level Agreement (SLA). Therefore, in terms of description and management of non-functional information, the disadvantages of not having a standard include the vendor lock-in and prevent the ecosystem to grow and handle extra functional aspects. In this paper, we present SLA4OAI, pioneering in extending OAS not only allowing the specification of SLAs, but also supporting some stages of the SLA-Driven API lifecycle with an open-source ecosystem. Finally, we validate our proposal having modeled 5488 limitations in 148 plans of 35 real-world APIs and show an initial interest from the industry with 600 and 1900 downloads and installs of the SLA Instrumentation Library and the SLA Engine.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21Ministerio de Educación, Cultura y Deporte FPU15/0298

Fostering SLA-Driven API Specifications

Software architecture tendencies are shifting to a microservice paradigm. In this context, RESTful APIs are being established the standard of integration. API designer often identifies two key issues to be competitive in such growing market. On the one hand, the generation of accurate documentation of the behavior and capabilities of the API to promote its usage; on the other hand, the design of a pricing plan that fits into the potential API user’s needs. Besides the increasing number of API modeling alternatives is emerging, there is a lack of proposals on the definition of flexible pricing plans usually contained in the Service Level Agreements (SLAs). In this paper we propose two different modeling techniques for the description of SLA in a RESTful API context: iAgree and SLA4OAI.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12-TIC-1867Ministerio de Economía y Competitividad TIN2014-53986-RED

ELeCTRA: Induced Usage Limitations Calculation in RESTful APIs

As software architecture design is evolving to microservice paradigms, RESTful APIs become the building blocks of applications. In such a scenario, a growing market of APIs is proliferating and developers face the challenges to take advantage of this reality. For example, third-party APIs typically define different usage limitations depending on the purchased Service Level Agreement (SLA) and, consequently, performing a manual analysis of external APIs and their impact in a microservice architecture is a complex and tedious task. In this demonstration paper, we present ELeCTRA, a tool to automate the analysis of induced usage limitations in an API, derived from its usage of external APIs. This tool takes the structural, conversational and SLA specifications of the API, generates a visual dependency graph and translates the problem into a constraint satisfaction optimization problem (CSOP) to obtain the optimal usage limitations.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12–TIC–1867Ministerio de Economía y Competitividad TIN2014-53986-REDTMinisterio de Educación, Cultura y Deporte FPU15/0298

Governify for APIs: SLA-Driven Ecosystem for API Governance

As software architecture design is evolving to a microservice paradigm, RESTful APIs are being established as the preferred choice to build applications. In such a scenario, there is a shift towards a growing market of APIs where providers offer different service levels with tailored limitations typically based on the cost. In such a context, while there are well-established standards to describe the functional elements of APIs (such as the OpenAPI Specification), having a standard model for Service Level Agreements (SLAs) for APIs may boost an open ecosystem of tools that would represent an improvement for the industry by automating certain tasks during the development. In this paper, we introduce Governify for APIs, an ecosystem of tools aimed to support the user during the SLA-Driven RESTful APIs’ development process. Namely, an SLA Editor, an SLA Engine and an SLA Instrumentation Library. We also present a fully operational SLA-Driven API Gateway built on the top of our ecosystem of tools. To evaluate our proposal, we used three sources for gathering validation feedback: industry, teaching and research.Ministerio de Economía y Competitividad TIN2015- 70560-RMinisterio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21Ministerio de Educación, Cultura y Deporte FPU15/0298

Towards SLA modeling for RESTful APIs

The term of API Economy is becoming increasingly used to describe the change of vision in how APIs can add value to the organizations. Furthermore, a greater automation of RESTful APIs management can suppose a competitive advantage for the company. New proposals are emerging in order to automatize some API governance tasks and increase the ease of use (e.g. generation of code and documentation). Despite that, the non-functional aspects are often addressed in a highly specific manner or even there not exists any solution for an automatic governance. Nevertheless, these properties are already defined in natural language at the Service Level Agreement (SLA) that both customer and provided have established. In this paper, we carry out a study on the *aaS industry and analyze the current both API modeling and SLA modeling proposals in order to identify the open challenges for an automatic RESTful API governance.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Economía y Competitividad P12–TIC-1867Ministerio de Economía y Competitividad TIN2014-53986-RED

Towards SLA-Driven API Gateways

As APIs are becoming popular to build Service-Based Ap- plications (SBA), API Gateways are being increasingly used to facilitate API features management. They o er API management functionalities such as pricing plans support, user authentication, API versioning or response caching. Some parts of the information that an API Gateway needs are already included into a Service Level Agreement (SLA), that providers use to describe the rights and the obligations of involved par- ties in the service. Unfortunately, current API Gateways do not use any SLA representation model nor SLA underlying technology, thereby miss- ing potential opportunities. In this paper we analyze the state of the art to justify the current situation and we identify some research challenges so as to achieve SLA-Driven API Gateways.European CommissionSpanish and the Andalusian R&D&I programs TIN201232273Spanish and the Andalusian R&D&I programs TIC5906Spanish and the Andalusian R&D&I programs P12TIC-1867Spanish and the Andalusian R&D&I programs TIN2014-53986-RED

An Analysis of RESTful APIs Offerings in the Industry

As distribution models of information systems are moving to XaaS paradigms, microservices architectures are rapidly emerging, having the RESTful principles as the API model of choice. In this context, the term of API Economy is being used to describe the increasing movement of the industries in order to take advantage of exposing their APIs as part of their service offering and expand its business model. Currently, the industry is adopting standard specifications such as OpenAPI to model the APIs in a standard way following the RESTful principles; this shift has supported the proliferation of API execution platforms (API Gateways) that allow the XaaS to optimize their costs. However, from a business point of view, modeling offering plans of those APIs is mainly done ad-hoc (or in a platform-dependent way) since no standard model has been proposed. This lack of standardization hinders the creation of API governance tools in order to provide and automate the management of business models in the XaaS industry. This work presents a systematic analysis of 69 XaaS in the industry that offer RESTful APIs as part of their business model. Specifically, we review in detail the plans that are part of the XaaS offerings that could be used as a first step to identify the requirements for the creation of an expressive governance model of realistic RESTful APIs. Additionally, we provide an open dataset in order to enable further analysis in this research line.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12-TIC-1867Ministerio de Educación, Cultura y Deportes FPU15/0298