Service Level Agreement Model Research Articles

RAaaS: Resource Allocation as a Service in multiple cloud providers

Cloud users require a set of specific computing needs for their applications, while cloud providers offer a variety of computing products and services on the Internet. These two cloud players make deals through the use of service level agreements (SLAs) where, for instance, prices and levels of quality of service (QoS) are defined. From the cloud user’s point of view, building a robust set of SLAs becomes a challenging problem when multiple cloud providers are present in the market. The allocation of resources in the cloud to run complex applications with guaranteed reliable, secure and acceptable response times is not an easy task, and this paper aims to tackle this problem. This work describes a resource allocation service that aims to optimize the user’s request of cloud resources (virtual machines — VMs) onto multiple Infrastructure-as-a-Service (IaaS) cloud providers. The Resource-Allocation-as-a-Service (RAaaS) proposed in this paper works as a standalone service between cloud users and cloud providers, and it relies on three different requirements: reliability, processing, and mutual trust. The proposed resource allocation service is carried out using the three very common types of VM billing models: on-demand, reserved and spot, where the spot cost model is employed to furnish low-cost resources for the application allocation to improve its reliability. The contributions of this paper are threefold: (i) a three-dimension SLA encompassing reliability, processing, and trust; (ii) an integer linear program (ILP) to schedule cloud-based VMs to applications considering the three-dimension SLA model, and (iii) a heuristic algorithm to mitigate possible QoS violations. Experimental results show that the proposed RAaaS procedure is capable of optimizing resource allocation considering multiple criteria in the SLA while mitigating the extra costs introduced by mutual trust between customers using redundant spot instances allocation.

NASLMRP: Design of a Negotiation Aware Service Level Agreement Model for Resource Provisioning in Cloud Environments

Cloud resource provisioning requires examining tasks, dependencies, deadlines, and capacity distribution. Scalability is hindered by incomplete or complex models. Comprehensive models with low-to-moderate QoS are unsuitable for real-time scenarios. This research proposes a Negotiation Aware SLA Model for Resource Provisioning in cloud deployments to address these challenges. In the proposed model, a task-level SLA maximizes resource allocation fairness and incorporates task dependency for correlated task types. This process's new tasks are processed by an efficient hierarchical task clustering process. Priority is assigned to each task. For efficient provisioning, an Elephant Herding Optimization (EHO) model allocates resources to these clusters based on task deadline and make-span levels. The EHO Model suggests a fitness function that shortens the make-span and raises deadline awareness. Q-Learning is used in the VM-aware negotiation framework for capacity tuning and task-shifting to post-process allocated tasks for faster task execution with minimal overhead. Because of these operations, the proposed model outperforms state-of-the-art models in heterogeneous cloud configurations and across multiple task types. The proposed model outperformed existing models in terms of make-span, deadline hit ratio, 9.2% lower computational cycles, 4.9% lower energy consumption, and 5.4% lower computational complexity, making it suitable for large-scale, real-time task scheduling.

AWESOME: an auction and witness enhanced SLA model for decentralized cloud marketplaces

In recent decades, the world has witnessed cloud computing as an essential technology that changes the traditional application Development and Operation (DevOps) lifecycle. However, current cloud software DevOps and Service Level Agreement (SLA) management often face challenges of 1) selecting the best fitting service providers, customizing services and planning capacities for large-scale distributed applications; 2) guaranteeing high-quality and trustworthy SLAs among multiple service providers; 3) enhancing the interoperability of cloud services across different providers; and 4) designing effective incentive models among stakeholders. This paper proposes a novel framework called Auction and Witness Enhanced trustworthy SLA for Open, decentralized service MarkEtplaces (AWESOME) to build a trustworthy cloud marketplace and address the above challenges. The proposed framework contains four subsystems: a customizable graphical user interface, an auction-based service selection model, a witness committee management mechanism, and a smart contract factory orchestration. We developed a prototype AWESOME decentralized application (DApp) based on the Ethereum blockchain. Extensive experiments are designed to evaluate the latency and cost of our model. The experimental results demonstrate that our model is economical and feasible.

Towards Automatic Network Slicing for the Internet of Space Things

The emergence of CubeSats as a viable means for realizing satellite networks at low costs has given rise to ubiquitous cyber-physical systems spanning air, ground, and space, in what is being recognized as the Internet of Space Things (IoST). IoST is expected to serve a wide variety of applications ranging from monitoring and reconnaissance to in-space backhauling, i.e., the network architecture must serve a plethora of application scenarios with differing service-level agreement (SLA) requirements over the same physical infrastructure in an end-to-end manner. At the same time, since the different use cases might belong to a variety of different stakeholders, IoST must support multi-tenancy and functional isolation of services. Consequently, a network slicing framework is vital to the success of IoST. To this end, an automatic network slicing framework for space-ground integrated networks is presented in this paper. The proposed framework has been designed to address the dual objectives of route computation and resource allocation with minimal SLA violations. Different from the existing state-of-the-art, the framework presented herein is purpose-built for ultra-dense CubeSat networks, and is fully automated. In other words, the framework is purely SLA-based, and does not require prior information concerning the resource requirements associated with a slice. Other key innovations introduced through this framework include a robust SLA model for slice customization, a novel topology construction mechanism, and a unique segment routing-based online admission control solution. Furthermore, the flexibility and efficacy of the proposed framework have been evaluated through a comprehensive use case driven evaluation scenario.

A novel service level agreement model using blockchain and smart contract for cloud manufacturing in industry 4.0

ABSTRACT The number of service offerings in cloud manufacturing continues to grow, so that service level agreement (SLA) within cloud manufacturing is increasingly used to ensure the coordination of the cross-organisational business processes between the cloud service providers (CSP) and cloud service consumers (CSC). The definition of SLA and monitoring SLA’s performance are significant and should be highly valued to ensure the effectiveness and efficiency of business services. At present, the third-party monitoring methods based on service credit are mainly applied in cloud manufacturing environments. There is no effective supervision mechanism to monitor the third party and no efficient punishment mechanism on SLA violation. To address aforementioned issues, this paper proposes a novel Service Level Agreement model by integrating Blockchain and Smart Contract (SLABSC), in which trust issues among CSP, CSC, and the third-party monitoring can be addressed through Blockchain technologies. The method proposed in this paper realises the full functionality of SLABSC and facilitates data security, and it can be used to supervise CSP to provide better services. Experiments results show that the performance of the proposed model is valid and efficient.

Implementation Scheme SLA and Network Availability Mechanism for Customer Service Provider

Increasingly complex network heterogeneity and network monitoring tasks become the management concentration of a large distributed production infrastructure with various business services requiring a centralized control monitoring system, with increasing network size, heterogeneity and complexity. The network monitoring and management solutions available are not only expensive but also difficult to use, configure and maintain. Manually routing pins to the wrong device on a large complex network is very complicated and time-consuming for Service Provider (SP). Thus, it is necessary to have an automatic system that immediately reports to the network Service Provider (SP) monitoring system regarding the type of error or alert, Network Availability and Service Level Agreement (SLA). This research presents the modeling design and implementation of Network Availability and SLA network systems for Service Provider (SP) organizations, by being based on open-source programming tools (Zabbix System) and intelligently integrating to monitor network devices, especially to get Network Availability and SLA parameters and values on a customer or customer. Monitoring Customers devices in the network in the form of a module alert parameter that will be applied so that it is seen and can be said to be a universal Plug & Play technology concept (UPnP). Monitoring system developed will provide value and quality of service (qos) output parameters in the form of measuring and taking test value parameters Network Availability and SLA modeling, which will produce an accurate Service Level Agreement (SLA) value parameter test, and become a reference for an agreement between a service provider and a customer. As a guarantee or link availability for the services provided by Service Provide (SP) to customers. With the SLA value fulfilled at 99.9% with a 99.5% agreement, Network availability is met with a percentage of 98.89% and Down time with a percentage of only 1% of the agreement 2%, and the latency value of the terrestrial transmission media obtained is 2 ms, from the 8 ms agreement and the obtained VSAT transmission media is 500-600 ms from the agreement latency value is 700 ms.

Risk-aware service level agreement modeling in smart grid

As advanced Smart Grid environments grow from a simple grid towards a complex provider ecosystem, there is an uncertain challenge on those grid environments that need to manage a risk paradigm. We present an automated risk-aware service level agreements modeling to the grid provider for speed automated pricing and getting better performance to program as an agent-oriented platform. The key idea of our novel approach is proposing a risk level agreements contract and a pricing model to decrease the complexity of previous methods from an off-line service level agreement to an on-line risk level agreement for managing the risk lifecycle of contracts used to record the rights and obligations of the services and their consumers. Based on a risk level agreements contract the model optimizes resource management according to the business objective level of the provider with an online risk-aware rendezvous to define the penalty level of the cost model. The corresponding quality of service criteria is defined based on multi-class risk-aware service level agreements between Smart Grid providers and their power consumers which include the tail distributions of the per-class costs in addition to the more standard quality of service metrics such as throughput and mean delays. Our empirical experiments show the benefits of the proposed approach.

SLA Management for Big Data Analytical Applications in Clouds

Recent years have witnessed the booming of big data analytical applications (BDAAs). This trend provides unrivaled opportunities to reveal the latent patterns and correlations embedded in the data, and thus productive decisions may be made. This was previously a grand challenge due to the notoriously high dimensionality and scale of big data, whereas the quality of service offered by providers is the first priority. As BDAAs are routinely deployed on Clouds with great complexities and uncertainties, it is a critical task to manage the service level agreements (SLAs) so that a high quality of service can then be guaranteed. This study performs a systematic literature review of the state of the art of SLA-specific management for Cloud-hosted BDAAs. The review surveys the challenges and contemporary approaches along this direction centering on SLA. A research taxonomy is proposed to formulate the results of the systematic literature review. A new conceptual SLA model is defined and a multi-dimensional categorization scheme is proposed on its basis to apply the SLA metrics for an in-depth understanding of managing SLAs and the motivation of trends for future research.

An Adaptive Service Monitoring System in a Cloud Computing Environment

Cloud computing is a trending area of information technology (IT). In a cloud environment, the Cloud service provider (CSP) provides all the functionalities to the users or customers in terms of services. With the rapid development of cloud computing, the performance of any cloud environment relies on the quality of services (QoS) at the time of providing the services. A service level agreement (SLA) increases the confidence of the user or customer to use the cloud services in a cloud environment. There should be negotiation between the CSP and users to achieve a strong SLA. Many existing SLA models are already developed. However, these models do not concentrate to maintain the quality in a long-time duration period. To solve this issue, a novel SLA model has been proposed in this article by using Fuzzy logic. Both the theoretical and simulation results show the proficiency of the proposed scheme over the existing schemes in a cloud computing environment.

CART, a Decision SLA Model for SaaS Providers to Keep QoS Regarding Availability and Performance

Cloud systems are becoming a powerful tool for business. The evidence of the advantages of offering infrastructure as a service (IaaS), platform as a service (PaaS), or software as a service (SaaS) is overwhelming. Therefore, for SaaS providers, it is essential to know the virtual resources required to optimize the service offered and to keep the quality of service (QoS) at the desired levels. This paper presents an analytic model cloud availability and response time (CART) for obtaining the best tradeoff between performance, cost, and availability in a cloud system aimed at providing software as a service. The model aims to guarantee the predetermined availability and response time (RT) agreed with customers in a service-level agreement (SLA) contract while minimizing the cost of the system. A client-transparent error recovery strategy has been considered along with a Poisson traffic model. A sensitivity analysis of the simulated and real workloads is presented to study how a specific SLA influences the cloud service performance regarding the guaranteed RT and availability. The results corroborate the goodness of the model proposed, adjusting the real system accurately. Furthermore, the obtained results provide useful guidelines for cloud or Web-server designers.

Per-service security SLAs for cloud security management: model and implementation

In the cloud computing context, Service Level Agreements (SLAs) 'tailored' to specific Cloud Service Customers (CSCs) seem to be still an utopia, and things are even worse as regards the security terms to be guaranteed. In fact, existing cloud SLAs focus only on a few service terms, and Cloud Service Providers (CSPs) mainly provide uniform guarantees for all offered services and for all customers, regardless of any particular service characteristics or of customer-specific needs. This paper presents a framework that enables the adoption of a per-service SLA model, supporting the automatic implementation of cloud security SLAs tailored to the needs of each customer for specific service instances. In particular, the process and the software architecture for per-service SLA implementation are shown. A case study application, related to the provisioning of a secure web container service, is presented and discussed, to demonstrate the feasibility and effectiveness of the proposed solution.

Per-service security SLAs for cloud security management: model and implementation

In the cloud computing context, Service Level Agreements (SLAs) 'tailored' to specific Cloud Service Customers (CSCs) seem to be still an utopia, and things are even worse as regards the security terms to be guaranteed. In fact, existing cloud SLAs focus only on a few service terms, and Cloud Service Providers (CSPs) mainly provide uniform guarantees for all offered services and for all customers, regardless of any particular service characteristics or of customer-specific needs. This paper presents a framework that enables the adoption of a per-service SLA model, supporting the automatic implementation of cloud security SLAs tailored to the needs of each customer for specific service instances. In particular, the process and the software architecture for per-service SLA implementation are shown. A case study application, related to the provisioning of a secure web container service, is presented and discussed, to demonstrate the feasibility and effectiveness of the proposed solution.

Cloud SLA Terms Analysis Based On Ontology

Services in cloud computing run under specified constraints defined in Service Level Agreement (SLA) which becomes the basic core that guarantee the Quality of Service (QoS). However, the ambiguity in agreement terms makes the consumer face new challenges especially in understanding and analyzing SLA document. These challenges increasingly rise when the consumer uses services from multiple providers; since each one has its own SLA terminology. In this paper, we have significantly automated the process of managing and analyzing cloud SLA using semantic web technologies like OWL (Ontology Web Language), SWRL (Semantic Web Rule Language) and SQWRL (Semantic Query-Enhanced Web Rule Language). We describe the cloud SLA modeling and analyzing approach that assists consumers automatically analyze terms of various SLA documents. A prototype implementation demonstrates the feasibility and the efficiency of our approach.

Management of Service Level Agreements for Cloud Services in IoT: A Systematic Mapping Study

Cloud computing and Internet of Things (IoT) are computing technologies that provide services to consumers and businesses, allowing organizations to become more agile and flexible. Therefore, ensuring quality of service (QoS) through service-level agreements (SLAs) for such cloud-based services is crucial for both the service providers and service consumers. As SLAs are critical for cloud deployments and wider adoption of cloud services, the management of SLAs in cloud and IoT has thus become an important and essential aspect. This paper investigates the existing research on the management of SLAs in IoT applications that are based on cloud services. For this purpose, a systematic mapping study (a well-defined method) is conducted to identify the published research results that are relevant to SLAs. This paper identifies 328 primary studies and categorizes them into seven main technical classifications: SLA management, SLA definition, SLA modeling, SLA negotiation, SLA monitoring, SLA violation and trustworthiness, and SLA evolution. This paper also summarizes the research types, research contributions, and demographic information in these studies. The evaluation of the results shows that most of the approaches for managing SLAs are applied in academic or controlled experiments with limited industrial settings rather than in real industrial environments. Many studies focus on proposal models and methods to manage SLAs, and there is a lack of focus on the evolution perspective and a lack of adequate tool support to facilitate practitioners in their SLA management activities. Moreover, the scarce number of studies focusing on concrete metrics for qualitative or quantitative assessment of QoS in SLAs urges the need for in-depth research on metrics definition and measurements for SLAs.

Quality of network economics optimisation using service level agreement modelling

AbstractThis paper analyses the relationships between different service level agreement (SLA) components, that is, the different types of quality metrics employed by infrastructure and service providers. We propose that the quality of network economics (QoNE) be used to evaluate the quality of a network path for a given SLA model. Our evaluation indicates the usefulness of the QoNE metric, and it provides a new mechanism for the networking community to address network design problems when incorporating new challenges, such as the Internet of Things. We show how the proposed model can be implemented in software‐defined network architecture applicable to networking technologies that include the interconnection of autonomous systems. Copyright © 2016 John Wiley & Sons, Ltd.

Cross-cutting 기반의 클라우드 서비스 품질 메트릭 및 SLA 명세 기법

클라우드 서비스가 증가하고 다양해짐에 따라 클라우드 서비스 사용자들의 요구사항을 만족하는 가장 적절한 서비스를 찾아주는 클라우드 서비스 브로커(CSB) 기술이 나타났다. CSB를 통해 클라우드 서비스가 사용되는 것을 촉진시키기 위해서는 서비스 수준 협약(SLA) 기반의 협상 과정을 통해 사용자들의 요구사항에 맞는 품질 수준을 보장하는 것이 중요하다. 그러나 클라우드 서비스 유형 별로 품질수준을 표현하는 측정 기준과 척도, 계산 방식이 서로 상이하다. 따라서 클라우드 서비스의 품질에 대한 가변성을 분석하고, 분석된 품질 수준을 보장 및 개선하기 위한 SLA 모델이 필요하다. 본 논문에서는 cross-cutting 개념을 적용하여 클라우드 서비스의 유형 별 품질 메트릭을 분석하고 사용자와 제공자 간의 품질 수준에 대한 협상을 담당하는 VSLA(Variable SLA) 메타모델을 제안한다.

SLA-driven dynamic cloud resource management

As the size and complexity of Cloud systems increase, the manual management of these solutions becomes a challenging issue as more personnel, resources and expertise are needed. Service Level Agreement (SLA)-aware autonomic cloud solutions enable managing large scale infrastructure management meanwhile supporting multiple dynamic requirement from users. This paper contributes to these topics by the introduction of Cloudcompaas, a SLA-aware PaaS Cloud platform that manages the complete resource lifecycle. This platform features an extension of the SLA specification WS-Agreement, tailored to the specific needs of Cloud Computing. In particular, Cloudcompaas enables Cloud providers with a generic SLA model to deal with higher-level metrics, closer to end-user perception, and with flexible composition of the requirements of multiple actors in the computational scene. Moreover, Cloudcompaas provides a framework for general Cloud computing applications that could be dynamically adapted to correct the QoS violations by using the elasticity features of Cloud infrastructures. The effectiveness of this solution is demonstrated in this paper through a simulation that considers several realistic workload profiles, where Cloudcompaas achieves minimum cost and maximum efficiency, under highly heterogeneous utilization patterns.

Reputation Improved Web Services Discovery Based on QoS

With an expanding of Web services giving same functionalities, Quality of Service (QoS) is becoming an important criterion for selection of the best available service. So users need to know QoS information and the reliability of this information .This article presents a new model of reputation improved Web services discovery considering the quality of services that include a reputation administrator to allocate reputation marks to the services based on customer feedback of their efficiency. The model is based on Service Level Agreements (SLAs) to ensure the standard of the process of discovery the quality specifications of the web services and it regulates perspectives from the two parties that is not the same and provides official definitions of quality of service (QoS) characteristics such that there is no vagueness in explaining characteristics. Practically we collected the present findings on SLA modeling and we presented a broker helps quality aware service discovery using the reputation marks in a service matching, ranking and selection algorithm based on our model.

Managing Enterprise Service Level Agreement

The continued trend of globalization and technology improvement like the internet and transportation have spawned an increasing number of complex service chains that span across local, regional and national boundaries. Service level agreement (SLA) plays a crucial role in gluing service chains together. In that regard, this paper provides a complete guidance of end-to-end lifecycle management of SLA, including SLA-aware service modelling and terms optimization, contract drafting and compliance tracking. Among these, the author introduces his work in the area of enterprise SLA optimization to address existing deficiencies in this area including a roadmap for industry-strength SLA optimization capability and an initial version of SLA modeling and optimization toolset—code-named SLA-OASIS. Some out-of-box toolsets for SLA contract drafting and compliance tracking are also introduced.