SLA management of non-computational services.

El incremento en el uso de arquitecturas orientadas a servicios en los últimos 15 años ha propiciado la propuesta de numerosas técnicas para automatizar y dar soporte al uso de dichos servicios. Un elemento fundamental en la provisión de servicios es el Acuerdo de Nivel de Servicio (ANS), donde se formalizan los requisitos y garantías de consumidor y proveedor respecto del rendimiento del servicio. Las propuestas para servicios computacionales, además de proveer modelos formales para describirlos, proponen la automatización de las diferentes etapas del ciclo de vida del ANS, tales como la negociación de las garantías para crear un ANS, el despliegue de servicios basados en el ANS, o la gestión de los recursos para cumplir las garantías provistas en el mismo. Sin embargo, en los servicios tradicionales, no computacionales, es decir, los servicios que no son ejecutados por recursos computacionales, tales como los servicios de logística o de desarrollo de software, la gestión de sus ANSs todavía se realiza por medios ad-hoc. Así, las soluciones existentes no pueden ser reutilizadas por diferentes servicios. Y, en la mayoría de los casos, esta gestión se hace de manera manual (p.e. revisión de los objetivos acordados en los ANSs de servicios de transporte), por lo que la evaluación de estos ANSs es susceptible a errores y se suele retrasar respecto a la ejecución del servicio (p.e. cuando el ANS ha finalizado), por lo que no se pueden tomar acciones preventivas para evitar el incumplimiento del ANS o estas acciones no son rentables. En estos escenarios, aparecen, además, acuerdos marco para un periodo largo (p.e. 1 aõ), durante el cual pueden aparecen ANSs relacionados con éste para un periodo más específico y el análisis de la coherencia entre acuerdos marco y acuerdos específicos es complicada de hacer durante la ejecución del servicio. En esta tesis, nos proponemos automatizar parcialmente la gestión de los ANSs de servicios no computacionales. Así, por un lado, proponemos que los modelos para servicios computacionales se extiendan a servicios no computacionales, de manera que permitan describir la operativa del servicio y sus garantías. Y, por otro lado, basado en estos modelos, proporcionamos el diseño de operaciones para gestionar el ciclo de vida de los ANS. Concretamente, estas operaciones se basan en las fases de despligue y evaluación del ANS. De forma específica, esta tesis propone tres contribuciones principales. Primero, (A) extender iAgree para dar soporte al modelado de los ANS de servicios no computacionales. Segundo, (B) dar soporte al ciclo de vida de dichos ANS mediante la formalización de las operaciones citadas (configuración del servicio basada en el ANS y monitorización del mismo) y, a partir de estas operaciones, implementamos una arquitectura de referencia para estas operaciones. Y, por último, (C) proveemos el modelado de la relación entre acuerdos marco y específicos que relacione sus términos junto con la formalización de las operaciones para el análisis que aparecen entre ellos. Otros aspectos del ciclo de vida del servicio y del ANS, como la gestión de los recursos para mejorar el rendimiento del servicio o el uso de técnicas (como machine learning) para la predicción del cumplimiento de los ANSs están fuera del contexto de esta tesis, pero se plantean como futuras líneas de extensión. Este trabajo se ha basado en ANSs reales de diferentes dominios, tales como servicios de Transporte y Logística, proveedores de Cloud or outsourcing de desarrollo TIC, que se han utilizado para validar las propuestas. Además, las contribuciones presentadas se han aplicado en el contexto de proyectos reales de soporte de sistemas TIC.The rise of computational services in the last 15 years brought the proposal of a number of techniques to automate and support their enactment. One key element in services is the Service Level Agreement (SLA), where the requirements of service customer are matched with the performance levels from the service provider to define service level guarantees and related responsibilities. The proposals from computational domains are oriented to automate the different stages in the SLA Lifecycle, such as the negotiation of terms which will form the SLA, the deployment of services based on the SLA artifact or the management of computational resources to accomplish SLA goals on runtime. However, traditional non-computational services, that is, services which are not performed by computational resources, such as logistics or software development services, are still supported by ad-hoc mechanisms. Therefore, the existing solutions for the management of their SLAs cannot be reused for other services. This management is usually manually performed (e.g.: reviewing of the goals of an SLA in transport service), so their evaluation is error-prone and delayed regarding the service execution (e.g.: when the SLA is finished), so preemptive actions to avoid SLA violations cannot be taken or/and are expensive to perform. Furthermore, these SLAs are sometimes described on a long term basis (frame agreements), and related SLAs can appear for a shorter term (specific agreements) and the analysis of the validity among them is complex to perform on runtime. In this dissertation, we aim at partially automate the management of SLAs in noncomputational services. On the one hand, we suggest that existing models for computational services can be extended to non computational services and enable the description of the service operative and their guarantees. And, on the other hand, we provide a design for operations to partially support the SLA Lifecycle, based on the previous models. Specifically, these operations are mainly focused on the deployment and fulfillment stages of the SLA. Therefore, the contributions of this dissertation are three. First, (A) providing a model to describe Service Level Agreements of non computational services, as an extension of iAgree, an existing model for SLAs of computational services. Second side, (B) supporting the SLA Lifecycle with the design of the aforementioned operations (service configuration based on SLA and monitoring of SLA) and implementing a reference architecture for such operations. And, lastly, (C) providing a model for frame and specific agreements which relates their terms and formalises the analysis operations among them. Other related operations of the service lifecycle as the management of resources to improve service performance or the use of novel techniques (such as machine learning) to predict the SLA accomplishment are out of the scope of this thesis but planned as future line of extension. The current dissertation has been based on real SLAs from different domains, such as Transport & Logistics, public Cloud providers or IT Maintenance outsourcing, which have been used to validate the proposal. And, furthermore, the contributions have been applied in the context of real IT Maintenance outsourcing projects

Towards the user-centric analysis of the availability in IaaS

Availability is a key property in computational services and, therefore, is guaranteed by Service Level Agreements (SLAs) from the majority infrastructure services, such as virtualization (Amazon EC2, Windows Azure, Google Cloud, Joyent, Rackspace, ...) and storage (Ama zon S3, Google Cloud Storage, ...). These SLAs describe availability in natural language and there are important differences in the scope and penalties that each service provides. Furthermore, descriptions use spe cific domain terms so they are difficult to understand by service cus tomers. These circumstances make that availability analysis is a tedious, error-prone and time-consuming task. In this paper, we describe in de tail this problem and provide a first approach to deal with these SLAs supported on current SLA analysis techniques

Redefining a Process Engine as a Microservice Platform

In recent years, microservice architectures have emerged as an agile approach for scalable web applications on cloud environments. As each microservice is developed and deployed independently, they can be developed in the platform and programming language that best suite their purposes, using a simple communication protocol, as REST APIs or asynchronous event-based collaborations, to compose them. In this paper, we argue that process engines provide an excellent platform to develop microservices whose business logic involves complex work flows or processes so that a Business Process language can be used as high level language to develop these services and a process engine to execute it. We identify the requirements for integrating a process engine in a microservice architecture and we propose how the communication and deployment in a microservice architecture can be handled by the process engine.Ministerio de Economía y Competitividad TIN2015-70560-R (BELI)Junta de Andalucía P12-TIC-1867 (COPAS)Junta de Andalucía P10-TIC-590

FAST-SE: An Esb Based Framework for SLA Trading

SLA driven service transaction has been identified as a key challenge to take advantage of a SOA. FAST System provides a software framework for the automated creation of SLAs. in particular it have been developed as an extension to the ESB (Enterprise Service Bus) paradigm to create a transparent SLA management layer that drives any service invocation. Our framework has been successfully applied in two different scenarios and provides an extensible architecture to address new domains

WS-Governance Tooling: SOA Governance Policies analysis and authoring

Governance is a capital issue in current Service Oriented Arcuitectures, and governance policies are at its base. The governance policies definition must be supported by proper languages and tools, allowing for comfortable and collaborative editing, consistency checking and the evaluation policy meeting. In this paper we present a policy analizer for WS-Governance (a governance policy definition language created by authors, described in [1]) together with an online editor and test suite with classical examples of WS-Governance Documents for consistency validation. Both the test model and the analysis tool prove the suitability of WS-Governance to define SOA governance policiesComisión Interministerial de Ciencia y Tecnología (CICYT) SETI (TIN2009-07366)Junta de Andalucía TIC-2533Junta de Andalucía TIC-590

On the Calculation of Process Performance Indicators

Performance calculation is a key factor to match corporate goals between different partners in process execution. However, although, a number of standards protocols and languages have recently emerged to support business process services in the industry, there is no standard related to monitoring of performance indicators over processes in these systems. As a consequence, BPMS use propietary languages to define measures and calculate them over process execution. In this paper, we describe two different approaches to compute performance mea- sures on business process decoupled from specific Business Process Man- agement System (BPMS) with an existing BPMS-independent language (PPINOT) to define indicators over business processes. Finally, some optimization techniques are described to increase calculation performance based on computing aggregated measures incrementally.Ministerio de Economía y Competitividad TIN2012–32273 (TAPAS)Junta de Andalucía TIC–5906 (THEOS)Junta de Andalucia COPAS (P12–TIC-1867)

Automated Validation of Compensable SLAs

A Service Level Agreement (SLA) regulates the provisioning of a service by defining a set of guarantees. Each guarantee sets a Service Level Objective (SLO) on some service metrics, and optionally a compensation that is applied when the SLO is unfulfilled or overfulfilled. Currently, there are software tools and research proposals that use the information about compensations to automate and optimise certain parts of the service management. However, they assume that compensations are well defined, which is too optimistic in some circumstances and can lead to undesirable situations. In this article we discuss about the notion of validity of guarantees with a compensation, which we refer to as compensable guarantees (CG). We describe an abstract model of CGs and we provide a technique that leverages constraint satisfaction problem solvers to automatically validate them. We also present a materialisation of the model of CGs in iAgree, a language to specify SLAs and a tooling support that implements our whole approach. An assessment over 319 CGs taken from 24 real-world SLAs suggests that the expressiveness and effectiveness of our proposal can pave the way for using CGs in a safer and more reliable way.Ministerio de Economía y Competitividad BELI (TIN2015-70560-R)Ministerio de Ciencia, Innovación y Universidades TIN2016-81978-REDTJunta de Andalucía P12--TIC--186

Automated analysis of feature models: Quo vadis?

Feature models have been used since the 90's to describe software product lines as a way of reusing common parts in a family of software systems. In 2010, a systematic literature review was published summarizing the advances and settling the basis of the area of Automated Analysis of Feature Models (AAFM). From then on, different studies have applied the AAFM in different domains. In this paper, we provide an overview of the evolution of this field since 2010 by performing a systematic mapping study considering 423 primary sources. We found six different variability facets where the AAFM is being applied that define the tendencies: product configuration and derivation; testing and evolution; reverse engineering; multi-model variability-analysis; variability modelling and variability-intensive systems. We also confirmed that there is a lack of industrial evidence in most of the cases. Finally, we present where and when the papers have been published and who are the authors and institutions that are contributing to the field. We observed that the maturity is proven by the increment in the number of journals published along the years as well as the diversity of conferences and workshops where papers are published. We also suggest some synergies with other areas such as cloud or mobile computing among others that can motivate further research in the future.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía TIC-186

The mediation of the environmental strategies in hotel financial performance in the context of Creating Shared Value

The tourism sector stakeholders in general, and the hotel companies stakeholders in particular, keep demanding more and more intensity the implementation and development of environmental policies that ensure sustainable tourist services, being the national and international large hotel chains the ones that make the biggest efforts in this area. There are numerous studies that value, in an unequal way, the cost and consequences of these environmental sustainability strategies on the performance of companies. For the hotel sector in particular, the scientific literature does not offer convincing enough conclusions in regards to the influence of these strategies on hotels performance. Some authors affirm that the clients are willing to pay higher rates when they recognise a high environmental component in the product. Other studies have concluded that when clients detect the proper implementation of energy saving, waste recycling or low emissions policies, they manifest very positive opinions on social media and online review platforms, notably improving the company’s reputation. In addition, the Creating Shared Value strategies between companies and stakeholders supported by Porter, consider that the redefinition of the companies’ configuration of their chain of value is highly important, including the implementation of environmental policies that involve the whole company. The results obtained grant clarity about the stimulus that entails the application of hotel environmental policies (in a shared value strategy) and the improvement of reputation, in hotel performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

!Agree Studio: a Platform to Edit and Validate Ws-Agreement Documents

The widespread use of SLA-regulated Cloud services, in which the violation of SLA terms may imply a penalty for the parties, have increased the importance and complexity of systems supporting the SLA lifecycle. Although these systems can be very different from each other, ranging from service monitoring platforms to auto-scaling solutions according to SLAs, they all share the need of having machine-processable and semantically valid SLAs. in this paper we present iAgree studio, the first application, up to our knowledge, that is able to edit and semantically validate agreement documents that are compliant with the WS–Agreement specification by checking properties such as its consistency, and the compliance between templates and agreement offers. in addition, it reports explanations when documents are not valid. Moreover, it allows users to combine the validation and explanation operations by means of a scenarios develope