Temporal-Awareness in SLAS. Why Should We Be Concerned?

Traditionally, Service Level Agreements have been decomposed in two sets of properties: functionals (what) and non-functionals (how). However, in our opinion, there has been a third key element that has had a minor attention from academy: temporal awareness (when). We believe temporality is a main concern that should be addressed in realistic scenarios. in doing so, this position paper discuss our experience in extending the specification WS-Agreement with a temporal Domain Specific Language; importantly, main aim of the paper is to provoke a debate about the importance of temporality in SLAs

The Triple Schizophrenia of the Software Engineering Researcher

In this paper we question the problem of a software engineering researcher, who in his daily work, has to deal with researching, teaching and learning activities at the same time. Likewise, we suggest the Action Research as the way to disentagle from that triple schizophrenia

Explaining the Non-Compliance between Templates and Agreement Offers in WS-Agreement

A common approach to the process of reaching agreements is the publication of templates that guide parties to create agreement offers that are then sent for approval to the template publisher. in such scenario, a common issue the template publisher must address is to check whether the agreement offer received is compliant or not with the template. Furthermore, in the latter case, an automated explanation of the reasons of such non-compliance is very appealing. Unfortunately, although there are proposals that deal with checking the compliance, the problem of providing an automated explanation to the non-compliance has not yet been studied in this context. in this paper, we take a subset of the WS-Agreement recommendation as a starting point and we provide a rigorous definition of the explanation for the non-compliance between templates and agreement offers. Furthermore, we propose the use of constraint satisfaction problem (CSP) solvers to implement it and provide a proof-of-concept implementation. The advantage of using CSPs is that it allows expressive service level objectives inside SLAs

Using Automated Analysis of Temporal-Aware SLAS in Logistics

Service level agreements (SLAs) establish the terms in which a logistics service may be provided or consumed. During the last years we have been studying techniques to perform an automated analysis of expressive and realistic SLAs, which makes the agreement creation process easier for involved parties. Firstly, we extended WS-Agreement specification to allow to apply any type of validity periods to SLA terms. Later, we dealt with the automated analysis of SLAs by proposing the explaining of SLAs inconsistencies and non-compliance scenarios. in this paper we show how these contributions are necessary to enable a logistic scenario of package tracking by providing examples for each proposal. We also include a final discussion on the convenience of performing a merge of all contributions to enable a better application of SLAs to logistic scenarios

An Initial Approach to Explaining SLA Inconsistencies

An SLA signed by all interested parties must be created carefully, avoiding contradictions between terms, because their terms could carry penalties in case of failure. However, this consistency checking may become a challenging task depending on the complexity of the agreement. As a consequence, an automated way of checking the consistency of an SLA document and returning the set of inconsistent terms of the agreement would be very appealing from a practical point of view. For instance, it enables the development of software tools that make the creation of correct SLAs and the consistency checking of imported SLAs easier for users. In this paper, we present the problem of explaining WSAgreement inconsistencies as a constraint satisfaction problem (CSP), and then we use a CSP solver together with an explanation engine to check the consistency and return the inconsistent terms. Furthermore, a proof-of-concept using Choco solver in conjunction with the Palm explanation engine has been developed

Building Industry-Ready Tools: FAMA Framework & ADA

Developing good academic tools has become an art that forces researchers to achieve tasks they are not supposed to do. These include coding, web and logo designing, testing, etc. It compromises the quality of a product that differs from what the industry expects from it. in this paper we propose professionalising the tool development to build industry-ready products that are a middle term between academic and industrial products. We summarise many of the decisions we have made in the last three years to build two successful products of this kind, and that we think that may help other researchers their best in tool building

An Elasticity-aware Governance Platform for Cloud Service Delivery

In cloud service provisioning scenarios with a changing demand from consumers, it is appealing for cloud providers to leverage only a limited amount of the virtualized resources required to provide the service. However, it is not easy to determine how much resources are required to satisfy consumers expectations in terms of Quality of Service (QoS). Some existing frameworks provide mechanisms to adapt the required cloud resources in the service delivery, also called an elastic service, but only for consumers with the same QoS expectations. The problem arises when the service provider must deal with several consumers, each demanding a different QoS for the service. In such an scenario, cloud resources provisioning must deal with trade-offs between different QoS, while fulfilling these QoS, within the same service deployment. In this paper we propose an elasticity-aware governance platform for cloud service delivery that reacts to the dynamic service load introduced by consumers demand. Such a reaction consists of provisioning the required amount of cloud resources to satisfy the different QoS that is offered to the consumers by means of several service level agreements. The proposed platform aims to keep under control the QoS experienced by multiple service consumers while maintaining a controlled cost.Junta de Andalucía P12--TIC--1867Ministerio de Economía y Competitividad TIN2012-32273Agencia Estatal de Investigación TIN2014-53986-RED

A Service Level Agreement Driven Framework to Customise Cloud Service Billing

Cloud service providers offer to their customers a variety of pricing policies, which range from the simple, yet widely used pay-as-you-go schema to complex discounted models. When executing the billing process, stakeholders have to consider usage metrics and service level objectives in order to obtain the correct billing and conform to the service level agreement in place. The more metrics, discount and compensations rules are added to the pricing schema, the more complex the billing generation results. In this paper we present a monitoring-based solution that enables the dynamically definition of both service level objectives and discount rules, so that providers can customise the billing generation process in terms of the service level agreement they offer. We validate our proposal in a real-world scenario, introducing a micro-service based software solution deployed in a Kubernetes cluster.Ministerio de Economía y Competitividad BELI (TIN2015-70560-R)Ministerio de Ciencia, Innovación y Universidades Horatio RTI2018-101204-B-C21Ministerio de Ciencia, Innovación y Universidades TIN2016-81978-REDTJunta de Andalucía P12-TIC-186