Service Level Agreement Compliance Research Articles

An Optimized Beluga Whale Approach for Migration to Reduce Power and Service Level Agreement in Real-Time System

Managing power consumption in cloud data centers has become a critical challenge. Live container migration is a technology supporting energy efficiency in this context. To address the hurdles of power consumption management, thereby mitigating carbon emissions and minimizing service level agreement (SLA) violations, we propose an approach utilizing a real-time server with the Beluga Whale Optimization Algorithm (BWOA) for container migration. The proposed approach aims to optimize energy consumption while ensuring SLA compliance. The BWOA, a machine learning-based method, is employed to predict the resource requirements of containers and migrate them to hosts with sufficient resources. We implemented the proposed approach in a real-time cloud server and compared its performance with other algorithms in terms of response time. The results demonstrate a remarkable 30% improvement in response time, leading to reduced SLA violations and optimized power consumption in containerized data centers.

C-SLA-MLO: Enhancing SLA Compliance in Industrial Wi-Fi through Cooperative Multilink Operation

In the dynamic landscape of Industry 4.0, robust wireless connectivity emerges as a critical enabler for Industrial Internet of Things (IIoT) applications. With the advent of Wi-Fi 7’s multilink operation (MLO), the demand for schedulers capable of meeting diverse Service Level Agreement (SLA) requirements within industrial environments becomes paramount. Addressing this need, this paper introduces Cooperative SLA-MLO (C-SLA-MLO), a novel distributed multilink scheduler that balances data across MLO channels to fulfill the SLA of STAs operating within the same BSS. We provide a simulation-based evaluation where we compare C-SLA-MLO with other benchmark approaches, in terms of SLA compliance when varying the SLA characteristics, the level of QoS, or background traffic, showcasing an average reduction of 90% in SLA deviation in the industrial use case. This study contributes practical insights for enhancing wireless connectivity in IIoT, offering potential benefits for industrial network optimization by exploiting the MLO feature brought by the new IEEE 802.11be.

UAVs-assisted QoS guarantee scheme of IoT applications for reliable mobile edge computing

Unmanned aerial vehicles (UAVs) assisted mobile edge computing (MEC) is an emerging network architecture that has been considered as a promising transformative service paradigm. It enhances the coverage of intelligent mobile communication network and promotes the rapid development of a wide range of internet of things (IoT) applications. However, the ever-increasing data transmission demands given rise by these IoT applications based on MEC have posed significant challenges to the service of quality (QoS) guarantee of UAVs-assisted MEC (UAVs-MEC) network. To address the issue, we propose a novel UAVs-MEC QoS guarantee scheme that can enhances the reliability of IoT applications in UAVs-MEC network. Specifically, a dynamic QoS-aware based service level agreement (SLA) compliance verification model for MEC service is proposed in the scheme. It can monitor and detect the consistency of dynamic QoS of IoT applications through UAVs to ensure the continuous SLA compliance of service provided by MEC. Additionally, an objective weight assignment method and an adaptive update method are presented to improve the accuracy and scalability of the scheme. Finally, the simulation experiments conducted using a real-world dataset show that the proposed scheme can efficiently and effectively verify the SLA compliance of MEC service for guaranteeing QoS of IoT applications in UAVs-MEC context while outperforms other existing SLA violation detection methods.

FinOps-driven optimization of cloud resource usage for high-performance computing using machine learning

Cloud computing is gaining popularity in high-performance computing applications. Its utilization enables advanced simulations when local computing resources are limited. However, cloud usage may increase costs and entail resource unavailability risks. This article presents an original approach that employs machine learning to predict long-term cloud resource usage. This enables optimizing resource utilization through appropriate reservation plans, reducing the associated costs. The solution developed utilizes statistical models, XGBoost, neural networks and the Temporal Fusion Transformer. Long-term prediction of cloud resource consumption, especially the Cloud Resource Usage Optimization System that is critical for prolonged simulations, involves using prediction results to dynamically create resource reservation plans across various virtual machine types for HPC on the Google Cloud Platform. Experiments using real-life production data demonstrate that the TFT prediction model improved prediction quality (by 31.4%) compared to the best baseline method, particularly in adapting to chaotic changes in resource consumption. However, it should be noted that the best prediction model in terms of error magnitude might not be the most suitable for resource reservation planning. This was validated by the neural network-based method, introducing an FR metric for forecast evaluation. Resource reservation plans were assessed both qualitatively and quantitatively, focusing on various aspects like a service-level agreement compliance and potential downtime. This paper is an extension of work originally presented during the International Conference on Computational Science — ICCS 2023, entitled “Long-Term Prediction of Cloud Resource Usage in High-Performance Computing”.

A blockchain-based SLA monitoring and compliance assessment for IoT ecosystems

A Service Level Agreement (SLA) establishes the trustworthiness of service providers and consumers in several domains; including the Internet of Things (IoT). Given the proliferation of Blockchain technology, we find it compelling to reconsider the assumption of trust and centralised governance typically practised in SLA management including monitoring, compliance assessment, and penalty enforcement. Therefore, we argue that, such critical tasks should be operated by blockchain-based smart contracts in a non-repudiable manner beyond the influence of any SLA party. This paper envisions an IoT scenario wherein a firefighting station outsources end-to-end IoT operations to a specialised service provider. The contractual relationship between them is governed by an SLA which stipulates a set of quality requirements and violation consequences. The main contribution of this paper lies in designing, deploying and empirically experimenting a novel blockchain-based SLA monitoring and compliance assessment framework in the context of IoT. This is done by utilising Hyperledger Fabric (HLF), an enterprise-grade blockchain technology. Our work highlights a set of considerations and best practice at two sides, the IoT application monitoring-side and the blockchain-side. Moreover, it experimentally validates the reliability of the proposed monitoring approach, which collects relevant metrics from each IoT component and examines them against the quality requirements stated in the SLA. Finally, we propose a novel design for smart contracts at the blockchain-side, analyse and benchmark the performance, and demonstrate that the new design proves to successfully handle Multiversion Concurrency Control (MVCC) conflicts typically encountered in blockchain applications, while maintaining sound throughput and latency.

Performance-Cost Trade-Off in Auto-Scaling Mechanisms for Cloud Computing.

Cloud computing has been widely adopted over the years by practitioners and companies with a variety of requirements. With a strong economic appeal, cloud computing makes possible the idea of computing as a utility, in which computing resources can be consumed and paid for with the same convenience as electricity. One of the main characteristics of cloud as a service is elasticity supported by auto-scaling capabilities. The auto-scaling cloud mechanism allows adjusting resources to meet multiple demands dynamically. The elasticity service is best represented in critical web trading and transaction systems that must satisfy a certain service level agreement (SLA), such as maximum response time limits for different types of inbound requests. Nevertheless, existing cloud infrastructures maintained by different cloud enterprises often offer different cloud service costs for equivalent SLAs upon several factors. The factors might be contract types, VM types, auto-scaling configuration parameters, and incoming workload demand. Identifying a combination of parameters that results in SLA compliance directly in the system is often sophisticated, while the manual analysis is prone to errors due to the huge number of possibilities. This paper proposes the modeling of auto-scaling mechanisms in a typical cloud infrastructure using a stochastic Petri net (SPN) and the employment of a well-established adaptive search metaheuristic (GRASP) to discover critical trade-offs between performance and cost in cloud services.The proposed SPN models enable cloud designers to estimate the metrics of cloud services in accordance with each required SLA such as the best configuration, cost, system response time, and throughput.The auto-scaling SPN model was extensively validated with 95% confidence against a real test-bed scenario with 18.000 samples. A case-study of cloud services was used to investigate the viability of this method and to evaluate the adoptability of the proposed auto-scaling model in practice. On the other hand, the proposed optimization algorithm enables the identification of economic system configuration and parameterization to satisfy required SLA and budget constraints. The adoption of the metaheuristic GRASP approach and the modeling of auto-scaling mechanisms in this work can help search for the optimized-quality solution and operational management for cloud services in practice.

SLA-aware operational efficiency in AI-enabled service chains: challenges ahead

Service providers compose services in service chains that require deep integration of core operational information systems across organizations. Additionally, advanced analytics inform data-driven decision-making in corresponding AI-enabled business processes in today’s complex environments. However, individual partner engagements with service consumers and providers often entail individually negotiated, highly customized Service Level Agreements (SLAs) comprising engagement-specific metrics that semantically differ from general KPIs utilized on a broader operational (i.e., cross-client) level. Furthermore, the number of unique SLAs to be managed increases with the size of such service chains. The resulting complexity pushes large organizations to employ dedicated SLA management systems, but such ‘siloed’ approaches make it difficult to leverage insights from SLA evaluations and predictions for decision-making in core business processes, and vice versa. Consequently, simultaneous optimization for both global operational process efficiency and engagement-specific SLA compliance is hampered. To address these shortcomings, we propose our vision of supplying online, AI-supported SLA analytics to data-driven, intelligent core workflows of the enterprise and discuss current research challenges arising from this vision. Exemplified by two scenarios derived from real use cases in industry and public administration, we demonstrate the need for improved semantic alignment of heavily customized SLAs with AI-enabled operational systems. Moreover, we discuss specific challenges of prescriptive SLA analytics under multi-engagement SLA awareness and how the dual role of AI in such scenarios demands bidirectional data exchange between operational processes and SLA management. Finally, we discuss the implications of federating AI-supported SLA analytics across organizations.

An integrated three-tier trust management framework in mobile edge computing using fuzzy logic.

Mobile edge computing (MEC) is introduced as part of edge computing paradigm, that exploit cloud computing resources, at a nearer premises to service users. Cloud service users often search for cloud service providers to meet their computational demands. Due to the lack of previous experience between cloud service providers and users, users hold several doubts related to their data security and privacy, job completion and processing performance efficiency of service providers. This paper presents an integrated three-tier trust management framework that evaluates cloud service providers in three main domains: Tier I, which evaluates service provider compliance to the agreed upon service level agreement; Tier II, which computes the processing performance of a service provider based on its number of successful processes; and Tier III, which measures the violations committed by a service provider, per computational interval, during its processing in the MEC network. The three-tier evaluation is performed during Phase I computation. In Phase II, a service provider total trust value and status are gained through the integration of the three tiers using the developed overall trust fuzzy inference system (FIS). The simulation results of Phase I show the service provider trust value in terms of service level agreement compliance, processing performance and measurement of violations independently. This disseminates service provider’s points of failure, which enables a service provider to enhance its future performance for the evaluated domains. The Phase II results show the overall trust value and status per service provider after integrating the three tiers using overall trust FIS. The proposed model is distinguished among other models by evaluating different parameters for a service provider.

Blockchain-Enabled SLA Compliance for Crowdsourced Edge-Based Network Function Virtualization

Network function virtualization (NFV) allows edge devices to host different types of virtual network functions (VNFs) and support Computing in the Network. Therefore, an edge device can abstract multiple VNFs of different infrastructure providers (InPs) as services and serve them at different times to act as a tenant for different InPs. Deploying edge devices is expensive and difficult to manage. Hence, crowdsourced edge devices can be used. To ensure the quality and availability of the services and the privacy of sensitive data of the service stakeholders, it is extremely important to establish a service level agreement (SLA) between an edge device owner and an InP. For monitoring of SLA compliance and enforcing accountability, a trusted platform is required. The traditional NFV management authority cannot be trusted due to its centralized characteristics. In this article, we propose a blockchain-powered framework for the SLA compliance of edge devices offering VNFs as services and introduce a smart contract-driven framework to establish trust in edge-based NFV. We analyze the performance of the proposed framework in the context of a private blockchain network.

Combining task scheduling and data replication for SLA compliance and enhancement of provider profit in clouds

Task scheduling and data replication are highly coupled resource management techniques that are widely used by cloud providers to improve the overall system performance and ensure service level agreement (SLA) compliance while preserving their own economic profit. However, balancing the trade-off between system performance and provider profit is very challenging. In this paper, we propose a novel scheduling algorithm called Bottleneck and Cost Value Scheduling (BCVS) algorithm coupled with a novel dynamic data replication strategy called Correlation and Economic Model-based Replication (CEMR). The main goal is to improve data access effectiveness in order to meet service level objectives in terms of response time SLORT and minimum availability SLOMA, while preserving the provider profit. The BCVS algorithm focuses on reducing system bottleneck situations caused by data transfer when the CEMR focuses on preventing future SLA violations and guaranteeing a minimum availability. An economic model is also proposed to estimate the cloud provider profit. Simulation results indicate that the proposed combination of scheduling and replication algorithms offers higher monetary profit for the cloud provider by up to 30% compared to existing strategies. Moreover, it allows better performance.

BloCkEd: Blockchain-Based Secure Data Processing Framework in Edge Envisioned V2X Environment

There has been an increasing trend of moving computing activities closer to the edge of the network, particularly in smart city applications (e.g., vehicle-to-everything – V2X). Such a paradigm allows the end user’s requests to be handled/processed by nodes at the edge of the network; thus, reducing latency, and preserving privacy of user data/activities. However, there are a number of challenges in such an edge computing ecosystem. Examples include (1) potential inappropriate utilization of resources at the edge nodes, (2) operational challenges in cache management and data integrity due to data migration between edge nodes, particularly when dealing with vehicular mobility in a V2X application, and (3) high energy consumption due to continuous link breakage and subsequent reestablishment of link(s). Therefore in this paper, we design a blockchain-based secure data processing framework for an edge envisioned V2X environment (hereafter referred to as BloCkEd ). Specifically, a multi-layered edge-enabled V2X system model for BloCkEd is presented, which includes the formulation of a multi-objective optimization problem. In addition, BloCkEd comprises an optimal container-based data processing scheme, and a blockchain-based data integrity management scheme, designed to minimize link breakage and reducing latency. Using Chandigarh City, India, as the scenario, we implement and evaluate the proposed approach in terms of its latency, energy consumption, and service level agreement compliance.

Implementing service level agreements in custody operations and software systems

This paper discusses a software design concept that allows custodians to map the content of their service level agreements (SLA) directly into their software systems and therefore their operations. It discusses the shortcomings of traditional software design concepts of transaction-processing systems when it comes to SLA monitoring and user guidance. The paper identifies the absence of a formalized description of the SLA as one of the major obstacles for the implementation of appropriate controls. As an alternative, the paper proposes a design that allows for such a formal description, which can be directly linked to specific processing rules, checks and parameter settings of the custody software. The current authors expect such a design to help business teams to proactively monitor potential upcoming SLA violations, therefore increasing SLA compliance and reducing operational risk.

A Multi-Objective Optimized Service Level Agreement Approach Applied on a Cloud Computing Ecosystem

The cloud ecosystem provides transformative advantages that allow elastically offering on-demand services. However, it is not always possible to provide adequate services to all customers and thus to fulfill service level agreements (SLA). To enable compliance with these agreements, service providers leave the customer responsible for determining the service settings and expect that the client knows what to do. Some studies address SLA compliance, but the existing works do not adequately address the problem of resource allocation according to clients' needs since they consider a limited set of objectives to be analyzed and fulfilled. In previous work, we have already addressed the problem considering a single-objective approach. In that work, we identified that the problem has a multi-objective characteristic since several attributes simultaneously influence the SLA agreement, which can lead to conflicts. This paper proposes a multi-objective combinatorial optimization approach for computational resources provisioning, seeking to optimize the efficient use of the infrastructure and provide the client with greater flexibility in contract closure.

“HySLAC” – A Conceptual Model for Service Level Agreement Compliance in Hybrid Cloud Architectures

“HySLAC” – A Conceptual Model for Service Level Agreement Compliance in Hybrid Cloud Architectures

Analysis of SLA Compliance in the Cloud - An Automated, Model-based Approach

Service Level Agreements (SLA) are commonly used to specify the quality attributes between cloud service providers and the customers. A violation of SLAs can result in high penalties. To allow the analysis of SLA compliance before the services are deployed, we describe in this paper an approach for SLA-aware deployment of services on the cloud, and illustrate its workflow by means of a case study. The approach is based on formal models combined with static analysis tools and generated runtime monitors. As such, it fits well within a methodology combining software development with information technology operations (DevOps).

Multi-criteria-Based Energy-Efficient Framework for VM Placement in Cloud Data Centers

Energy efficiency has become a prime concern in this evolving era of cloud computing. In recent years, several VM consolidation techniques were proposed. However, they involve single-criterion‐based host selection methods, which are unsuitable for the dynamic cloud environment. Cloud data centers need an efficient utilization of physical host resources. The selected hosts for VMs deployment must ensure the least energy consumption and service ‐level agreement (SLA) violations simultaneously. There is a lack of multi-criteria‐based solution which considers multiple resources to select hosts for the deployment of VMs. This paper presents a VM deployment framework that considers multiple criteria, i.e., reducing energy consumptions and SLA violations simultaneously while determining target hosts for VMs placement. The article proposes an Improved Technique for Order of Preference by Similarity to Ideal Solution-based Host Selection Policy for VM deployment on the target hosts in terms of energy efficiency. It manages the trade-off between energy consumption and SLA compliance. A case study is demonstrated to prove the usefulness and appropriateness of the proposed framework. The results show that our framework is promising and provides more efficiency in the use of cloud resources and maintaining SLA.

Green Service Level Agreement Compliance for Optical WDM Networks

Green Service Level Agreement Compliance for Optical WDM Networks

PRESENCE: Monitoring and Modelling the Performance Metrics of Mobile Cloud SaaS Web Services

Service Level Agreements (SLAs) are defining the quality of the services delivered from the Cloud Services Providers (CSPs) to the cloud customers. The services are delivered on a pay-per-use model. The quality of the provided services is not guaranteed by the SLA because it is just a contract. The developments around mobile cloud computing and the advent of edge computing technologies are contributing to the diffusion of the cloud services and the multiplication of offers. Although the cloud services market is growing for the coming years, unfortunately, there is no standard mechanism which exists to verify and assure that delivered services satisfy the signed SLA agreement in an automatic way. The accurate monitoring and modelling of the provided Quality of Service (QoS) is also missing. In this context, we aim at offering an automatic framework named PRESENCE, to evaluate the QoS and SLA compliance of Web Services (WSs) offered across several CSPs. Yet unlike other approaches, PRESENCE aims at quantifying in a fair and by stealth way the performance and scalability of the delivered WS. This article focuses on the first experimental results obtained on the accurate modelisation of each individual performance metrics. Indeed, 19 generated models are provided, out of which 78.9% accurately represent the WS performance metrics for two representative SaaS web services used for the validation of the PRESENCE approach. This opens novel perspectives for assessing the SLA compliance of Cloud providers using the PRESENCE framework.

SmartVM: a SLA-aware microservice deployment framework

Software-as-a-Service is becoming the prevalent way of software delivery. The popularisation of microservices architecture and containers has facilitated the efficient development of complex SaaS applications. Yet, for average SaaS vendors, there are a lot of challenges in managing microservices at a large scale while meeting the Quality-of-Service constraints. In this paper, we present SmartVM, a business Service-Level-Agreement (SLA) aware, microservice-centric deployment framework, designed to streamline the process of building and deploying dynamically-scalable microservices that can handle traffic spikes in a cost-efficient manner. We also compare our approach with traditional monolithic and the state-of-the-art microservice deployment approaches. The evaluation results show our approach advances in deployment cost, resource utilisation, and SLA compliance.

Inventory Allocation in the Presence of Service‐Level Agreements

Retailers often use service‐level agreements (SLAs) to evaluate their supplier's performance. Based on an examination of 70 SLAs from practice, we conclude that in terms of evaluating fill rate, these SLAs vary in at least three key dimensions: (i) Supplier performance can be evaluated for each demand request or over some longer horizon, (ii) the acceptable fill rate can be 100% or something less than 100%, and (iii) the non‐compliance charge can be a flat fee, a per‐unit‐short fee, or both. For a supplier operating a periodic‐review inventory system and serving multiple retailers, each with an SLA, we investigate the impact of inventory allocation rules on SLA compliance and expected non‐compliance costs across the three dimensions of review horizon, fill rate target and non‐compliance cost structure. We derive several analytic results when retailers are symmetric. For the single‐period setting and a fill rate target of 100%, we characterize the optimal allocation rule and rank other rules common in practice and the literature. We also characterize the optimal rule for the single‐period setting when the fill rate target is less than 100% and the SLA specifies a flat‐fee non‐compliance charge. In the multiple‐period case, we characterize the optimal rule when the fill rate target is 100%. When the fill rate target is less than 100% and the performance review horizon is more than one period, we develop a simple heuristic that outperforms common allocation rules.