Service-level agreement

About: Service-level agreement is a research topic. Over the lifetime, 4358 publications have been published within this topic receiving 75333 citations. The topic is also known as: SLA.

CSLAOnto: A Comprehensive Ontological SLA Model in Cloud Computing

Abstract: Cloud computing is an emerging topic in the information technology sector. The rapid evolution of this technology led to the emergence of new interaction models between its actors. However, the absence of a universally accepted format of the service level agreement (SLA) governing the relationships between the different actors of cloud increases its complexity. In addition, the dynamic nature of the cloud could lead to severe SLA violations. This undesirable but currently unavoidable situation may lead to penalizing providers and forcing customers to evaluate their SLAs permanently. In this paper, we propose a generic and semantically richer ontology-based model for SLA to improve its definition and its evaluation in cloud computing. Through this model, we have developed a prototype to validate our model and our monitoring process where SLA evaluation and guarantee actions triggering are automatically performed.

Ontology of Secure Service Level Agreement

Abstract: Maintaining security and privacy in the Cloud is a complex task. The task is made even more challenging as the number of vulnerabilities associated with the cloud infrastructure and applications are increasing very rapidly. Understanding the security service level agreements (SSLAs) and privacy policies offered by service and infrastructure providers is critical for consumers to assess the risks of the Cloud before they consider migrating their IT operations to the Cloud. To address these concerns relative to the assessment of security and privacy risks of the Cloud, we have developed ontologies for representing security SLAs (SSLA) in this paper. Our ontologies for SSLAs can be used to understand the security agreements of a provider, to negotiate desired security levels, and to audit the compliance of a provider with respect to federal regulations (such as HIPAA).

Enabling service-level agreement renegotiation through extending WS-Agreement specification

Abstract: WS-Agreement is a language and protocol designed for creating service-level agreements (SLAs) based on initial offers, and for monitoring those offers at runtime The definition of WS-Agreement protocol is very general and does not contemplate the possibility of changing an agreement at runtime This paper presents extensions of the WS-Agreement specification to support the dynamic nature of SLAs by allowing the possibility of SLA renegotiation at runtime The extended WS-Agreement specification has been implemented and tested Within this implementation, the concept of renegotiation is demonstrated through the ability to create more than one SLA at runtime An evaluation is conducted to examine the profits a service provider may gain through renegotiation, as well the savings resulting from rescuing the SLA from violations as a consequence of avoiding paying penalties The results show that making the SLA terms adaptable and changeable is a viable mechanism that provides flexibility to the service provider and service consumer

Multi-Criteria Virtual Machine Placement in Cloud Computing Environments: A literature Review

Abstract: Cloud computing is a revolutionary process that has impacted the manner of using networks. It allows a high level of flexibility as Virtual Machines (VMs) run elastically workloads on physical machines in data centers. The issue of placing virtual machines (VMP) in cloud environments is an important challenge that has been thoroughly addressed, although not yet completely resolved. This article discusses the different problems that may disrupt the placement of VMs and Virtual Network Functions (VNFs), and classifies the existing solutions into five major objective functions based on multiple performance metrics such as energy consumption, Quality of Service, Service Level Agreement, and incurred cost. The existing solutions are also classified based on whether they adopt heuristic, deterministic, meta-heuristic or approximation algorithms. The VNF placement in 5G network is also discussed to highlight the convergence toward optimal usage of mobile services by including NFV/Software-Defined-Network technologies.

SLA-Based Sharing Economy Service with Smart Contract for Resource Integrity in the Internet of Things

Abstract: Recently, technology startups have leveraged the potential of blockchain-based technologies to govern institutions or interpersonal trust by enforcing signed treaties among different individuals in a decentralized environment. However, it is going to be hard enough convincing that the blockchain technology could completely replace the trust among trading partners in the sharing economy as sharing services always operate in a highly dynamic environment. With the rapid expanding of the rental market, the sharing economy faces more and more severe challenges in the form of regulatory uncertainty and concerns about abuses. This paper proposes an enhanced decentralized sharing economy service using the service level agreement (SLA), which documents the services the provider will furnish and defines the service standards the provider is obligated to meet. The SLA specifications are defined as the smart contract, which facilitates multi-user collaboration and automates the process with no involvement of the third party. To demonstrate the usability of the proposed solution in the sharing economy, a notebook sharing case study is implemented using the Hyperledger Fabric. The functionalities of the smart contract are tested using the Hyperledger Composer. Moreover, the efficiency of the designed approach is demonstrated through a series of experimental tests using different performance metrics.