SERVICE LEVEL AGREEMENTS AND DEPENDABILITY

Dependability ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 27-30
Author(s):  
V. A. Netes
Keyword(s):  
Service Provider ◽  
Service Providers ◽  
Service Level Agreement ◽  
Service Level ◽  
Piecewise Constant Function ◽  
Availability Factor ◽  
Sla Violation ◽  
Wide Range ◽  
Standard Values ◽  
The One

The Service Level Agreement (SLA) is an efficient and proven tool for regulation of the relations between the supplier and the user of services that is designed to ensure their quality. Such agreements are well known and successfully used in the information and communication industry. They are also applicable in other areas. Essentially, SLA stipulates certain requirements for the service level of which the fulfilment is guaranteed by the provider. In case of SLA violation the service provider is usually financially liable. As a rule, in such cases the user is remunerated with a discount for services provided in the following accounting period. Dependability requirements are an important part of the SLA. The purpose of this paper is to familiarize a wide range of experts from various industries with the general matters of SLA application and the aspects related to the dependability requirements specification. The paper refers to the relevant documents of international standardization organizations (ITU, ISO/IEC, ETSI, TMForum) and the Russian standards. Recommendations are given for selecting the dependability indicators and standard values to be included in the SLA, as well as for defining the amounts of compensation payed by service providers to the customers in case of non-compliance with requirements for the availability factor. The availability factor is normally used in the SLA as the primary dependability indicator that defines the allowable total time of non-operability over the specified base period. Additionally, a client might be interested in restricting the duration of each individual downtime as well. For that purpose, the guaranteed recovery time can also be specified and exceeding this time would be deemed an SLA violation. The choice of the standard values for inclusion in the SLA is a search for a compromise between the intent to satisfy the user requirements and the wish to get ahead of the competition on the one hand and the requirement to ensure the feasibility of the assumed obligations and minimize the risk of SLA violation that involve financial and reputational losses on the other hand. Therefore, before proposing an SLA to a customer, a service provider must thoroughly analyze its actual ability to make sure that the probability of SLA requirements violation is sufficiently low. The computational or computational and experimental methods are suggested for its evaluation. The amount of compensation for a violation depends on its gravity, i.e. the achieved and the standard values of an indicator. In practice, this relation is usually expressed with a step (piecewise constant) function. A formula is proposed that expresses the theoretical relation between the relative amount of compensation for violation of the availability factor requirements and the severity of violation and the standard value of this indicator. It can be used in defining the technically substantiated reference for SLA conditions development and assessment, of which the value will be relevant to both the service providers and users.

scholarly journals DBaaS Multitenancy, Auto-tuning and SLA Maintenance in Cloud Environments: a Brief Survey

2018 ◽  
Vol 11 (2) ◽  
pp. 30-42
Author(s):  
Vinicius Da Silveira Segalin ◽  
Carina Friedrich Dorneles ◽  
Mario Antonio Ribeiro Dantas
Keyword(s):  
Data Storage ◽  
Service Providers ◽  
Research Work ◽  
Service Level Agreement ◽  
Service Level ◽  
Resources Management ◽  
Database As A Service ◽  
Cloud Environments ◽  
And Performance ◽  
The One

Cloud computing is a paradigm that presents many advantages to both costumers and service providers, such as low upfront investment, pay-per-use and easiness of use, delivering/enabling scalable services using Internet technologies. Among many types of services we have today, Database as a Service (DBaaS) is the one where a database is provided in the cloud in all its aspects. Examples of aspects related to DBaaS utilization are data storage, resources management and SLA maintenance. In this context, an important feature, related to it, is resource management and performance, which can be done in many different ways for several reasons, such as saving money, time, and meeting the requirements agreed between client and provider, that are defined in the Service Level Agreement (SLA). A SLA usually tries to protect the costumer from not receiving the contracted service and to ensure that the provider reaches the profit intended. In this paper it is presented a classification based on three main parameters that aim to manage resources for enhancing the performance on DBaaS and guarantee that the SLA is respected for both user and provider sides benefit. The proposal is based upon a survey of existing research work efforts.

Fuzzy rule based SLA generation algorithms for web based multi party negotiation systems

2020 ◽  
Vol 39 (6) ◽  
pp. 8345-8356
Author(s):  
M. Alamelu ◽  
T.S. Pradeep Kumar ◽  
V. Vijayakumar
Keyword(s):  
Service Provider ◽  
Service Providers ◽  
Service Level Agreement ◽  
Fuzzy Rule ◽  
Service Level ◽  
Rule Base ◽  
Web Based ◽  
Multilateral Negotiation ◽  
Service Consumer

Service Level Agreement (SLA) is an agreement between the service provider and consumer to provide the verifiable quality of services. Using the valuable metrics in SLA, a service consumer could easily evaluate the service provider. Though there are different types of SLA models are available between the consumer and provider, the proposed approach describes the Fuzzy rule base SLA agreement generation among multiple service providers. A negotiation system is designed in this work to collect the different sets of provider services. With their desired quality metrics, a common Fuzzy based SLA report is generated and compared against the existing consumer requirements. From the analysis of the common agreement report, consumers can easily evaluate the best service with the desired Impact service, cost and Quality. The main advantage of this approach is that it reduces the time consumption of a consumer. Moreover, the best service provider can be selected among multiple providers with the desired QoS parameters. At the same time, the bilateral negotiation is enhanced with the approach of multilateral negotiation to improve the searching time of consumers.

An SLA-Based Auction Pricing Method Supporting Web Services Provisioning

2011 ◽  
pp. 224-259
Author(s):  
Jia Zhang ◽  
Ning Zhang ◽  
Liang-Jie Zhang
Keyword(s):  
Web Services ◽  
Prediction Model ◽  
Service Providers ◽  
Formal Model ◽  
Service Level Agreement ◽  
Risk Preference ◽  
Service Level ◽  
Preference Elicitation ◽  
The One ◽  
New Research

Applying auctions to Web services selection and invocation calls for examination due to the unique features of Web services, such as interoperable machine-to-machine interactions and re-enterable bargaining services. In this chapter we propose a formal model for Web services-based auctions. Examining the one-sided sealed auction type, we prove mathematically that service requestors’ risk preferences could lead to different pricing strategies for service providers towards higher profit. We argue that Service Level Agreement (SLA) documents can be used to analyze service requestors’ preferences. On top of WS-Agreement, we propose a basic service requestor risk preference elicitation algorithm, as well as a historical data-based service requestor risk preference prediction model. Guidelines are provided to iteratively approach the learning rate of the proposed risk preference prediction model. The methods and techniques presented in this chapter can be reused to investigate and examine more facades of services-oriented auctions, towards establishing a new research realm on comprehensive services-oriented auctions.

scholarly journals Service Broker-Based Architecture Using Multi-Criteria Decision Making for Service Level Agreement

2019 ◽  
Vol 13 (1) ◽  
pp. 20
Author(s):  
Imane Haddar ◽  
Brahim Raouyane ◽  
Mostafa Bellafkih
Keyword(s):  
Decision Making ◽  
Service Provider ◽  
Network Architecture ◽  
Service Providers ◽  
Service Level Agreement ◽  
Service Selection ◽  
Service Level ◽  
Multi Criteria Decision Making ◽  
Sla Management ◽  
Set Up

With the on-going trends of the telecom services, the number of service providers with similar functionalities is undergoing a rapid growth. The customers face the difficulty to decide which service provider can satisfy their needs and full their requirements. Negotiating contracts between involved parts, and hiding heterogeneity in the distributed network environment has been challenging for telecom operators and service providers. Different languages exist to describe the Service Level Agreement (SLA), which is a contract between a service provider and a customer. However, since each service provider expresses his SLA in his own way, it disrupts the customer's choice of the best service provider, and leads to a bad contract management. In this respect, we propose a novel architecture for service selection, and SLA management between different stakeholders in our network architecture. The idea is to set up a smart broker where we implemented a Multi-Criteria Decision Making (MCDM) method to maximize utility function so that the customer can choose services with required QoS performances. We also came up with the idea of settling a negotiation model for the SLA, and a context based SLA contract ontology in IP Multimedia Subsystem (IMS) network is also proposed to provide users with a clear model to express their requirements and preferences. Moreover, we used the New Generation Operations Systems and Software (NGOSS) Framework to model and analyze networks and services actions. To better understand the relationship and the projection of NGOSS Framework and IMS platform, we introduce an SLA management and monitoring architecture in IMS network.

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

2021 ◽  
Vol 7 ◽  
pp. e700
Author(s):  
Merrihan B.M. Mansour ◽  
Tamer Abdelkader ◽  
Mohamed Hashem ◽  
El-Sayed M. El-Horbaty
Keyword(s):  
Service Provider ◽  
Trust Management ◽  
Service Providers ◽  
Service Level Agreement ◽  
Cloud Service ◽  
Service Level ◽  
Edge Computing ◽  
Trust Value ◽  
Management Framework ◽  
Cloud Service Providers

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.

scholarly journals Conceptual Service Level Agreement Mechanism to Minimize the SLA Violation with SLA Negotiation Process in Cloud Computing Environment

2021 ◽  
Vol 18 (2(Suppl.)) ◽  
pp. 1020
Author(s):  
Narander Kumar ◽  
Surendra Kumar
Keyword(s):  
Cloud Computing ◽  
Service Provider ◽  
Service User ◽  
Service Providers ◽  
Service Level Agreement ◽  
Cloud Service ◽  
Service Level ◽  
Negotiation Process ◽  
Cloud Computing Service ◽  
Cloud Service Providers

Online service is used to be as Pay-Per-Use in Cloud computing. Service user need not be in a long time contract with cloud service providers. Service level agreements (SLAs) are understandings marked between a cloud service providers and others, for example, a service user, intermediary operator, or observing operators. Since cloud computing is an ongoing technology giving numerous services to basic business applications and adaptable systems to manage online agreements are significant. SLA maintains the quality-of-service to the cloud user. If service provider fails to maintain the required service SLA is considered to be SLA violated. The main aim is to minimize the SLA violations for maintain the QoS of their cloud users. In this research article, a toolbox is proposed to help the procedure of exchanging of a SLA with the service providers that will enable the cloud client in indicating service quality demands and an algorithm as well as Negotiation model is also proposed to negotiate the request with the service providers to produce a better agreement between service provider and cloud service consumer. Subsequently, the discussed framework can reduce SLA violations as well as negotiation disappointments and have expanded cost-adequacy. Moreover, the suggested SLA toolkit is additionally productive to clients so clients can secure a sensible value repayment for diminished QoS or conceding time. This research shows the assurance level in the cloud service providers can be kept up by as yet conveying the services with no interruption from the client's perspective

A Novel QoS Aware Shortest Path Algorithm for VSDN

2017 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
Amandeep Kaur Sandhu ◽  
Jyoteesh Malhotra
Keyword(s):  
Energy Consumption ◽  
Shortest Path ◽  
Service Providers ◽  
Service Level Agreement ◽  
Service Level ◽  
Software Defined Networks ◽  
Shortest Path Algorithm ◽  
Internet Service ◽  
Decrease Energy Consumption

This article describes how a rapid increase in usage of internet has emerged from last few years. This high usage of internet has occurred due to increase in popularity of multimedia applications. However, there is no guarantee of Quality of Service to the users. To fulfill the desired requirements, Internet Service Providers (ISPs) establish a service level agreement (SLA) with clients including specific parameters like bandwidth, reliability, cost, power consumption, etc. ISPs make maximum SLAs and decrease energy consumption to raise their profit. As a result, users do not get the desired services for which they pay. Virtual Software Defined Networks are flexible and manageable networks which can be used to achieve these goals. This article presents shortest path algorithm which improves the matrices like energy consumption, bandwidth usage, successful allocation of nodes in the network using VSDN approach. The results show a 40% increase in the performance of proposed algorithms with a respect to existing algorithms.

Broker-based optimization of SLA negotiations in cloud computing

2021 ◽  
Vol 17 (2) ◽  
pp. 179-195
Author(s):  
Priyanka Bharti ◽  
Rajeev Ranjan ◽  
Bhanu Prasad
Keyword(s):  
Cloud Computing ◽  
Service Providers ◽  
Service Level Agreement ◽  
Cloud Service ◽  
Service Level ◽  
Cloud Environment ◽  
Negotiation Strategies ◽  
Sla Negotiation ◽  
Conflicting Interests ◽  
The Impact

Cloud computing provisions and allocates resources, in advance or real-time, to dynamic applications planned for execution. This is a challenging task as the Cloud-Service-Providers (CSPs) may not have sufficient resources at all times to satisfy the resource requests of the Cloud-Service-Users (CSUs). Further, the CSPs and CSUs have conflicting interests and may have different utilities. Service-Level-Agreement (SLA) negotiations among CSPs and CSUs can address these limitations. User Agents (UAs) negotiate for resources on behalf of the CSUs and help reduce the overall costs for the CSUs and enhance the resource utilization for the CSPs. This research proposes a broker-based mediation framework to optimize the SLA negotiation strategies between UAs and CSPs in Cloud environment. The impact of the proposed framework on utility, negotiation time, and request satisfaction are evaluated. The empirical results show that these strategies favor cooperative negotiation and achieve significantly higher utilities, higher satisfaction, and faster negotiation speed for all the entities involved in the negotiation.

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