Service Level Agreements Management Research Articles

Service level agreement management framework for utility-oriented computing platforms

With the increasing popularity of utility-oriented computing where the resources are traded as services, efficient management of quality of service (QoS) has become increasingly significant to both service consumers and service providers. In the context of distributed multimedia content adaptation deployment on service-oriented computing, how to ensure the stringent QoS requirements of the content adaptation is a significant and immediate challenge. However, QoS guarantees in the distributed multimedia content adaptation deployment on service-oriented platform context have not been accorded the attention it deserves. In this paper, we address this problem. We formulate the SLA management for distributed multimedia content adaptation deployment on service-oriented computing as an integer programming problem. We propose an SLA management framework that enables the service provider to determine deliverable QoS before settling SLA with potential service consumers to optimize QoS guarantees. We analyzed the performance of the proposed strategy under various conditions in terms of the SLA success rate, rejection rate and impact of the resource data errors on potential violation of the agreed upon SLA. We also compared the proposed SLA management framework with a baseline approach in which the distributed multimedia content adaptation is deployed on a service-oriented platform without SLA consideration. The results of the experiments show that the proposed SLA management framework substantially outperforms the baseline approach confirming that SLA management is a core requirement for the deployment of distributed multimedia content adaptation on service-oriented systems.

A Framework for Consumer-Centric SLA Management of Cloud-Hosted Databases

Service Level Agreements (SLA) represent the contract which captures the agreed upon guarantees between a service provider and its customers. The specifications of existing service level agreements (SLA) for cloud services are not designed to flexibly handle even relatively straightforward performance and technical requirements of consumer applications. In this article, we present a novel approach for SLA-based management of cloud-hosted databases from the consumer perspective. We present an end-to-end framework for consumer-centric SLA management of cloud-hosted databases. The framework facilitates adaptive and dynamic provisioning of the database tier of the software applications based on application-defined policies for satisfying their own SLA performance requirements, avoiding the cost of any SLA violation and controlling the monetary cost of the allocated computing resources. In this framework, the SLA of the consumer applications are declaratively defined in terms of goals which are subjected to a number of constraints that are specific to the application requirements. The framework continuously monitors the application-defined SLA and automatically triggers the execution of necessary corrective actions (scaling out/in the database tier) when required. The framework is database platform-agnostic, uses virtualization-based database replication mechanisms, and requires zero source code changes of the cloud-hosted software applications. The experimental results demonstrate the effectiveness of our SLA-based framework in providing the consumer applications with the required flexibility for achieving their SLA requirements.

Renegotiation in Service Level Agreement Management for a Cloud-Based System

Managing Service Level Agreement (SLA) within a cloud-based system is important to maintain service continuity and improve trust due to cloud flexibility and scalability. We conduct a general review on cloud-based systems to understand how service continuity and trust are addressed in cloud SLA management. The review shows that SLA renegotiation is necessary to improve trust and maintain service continuity; however, research on SLA renegotiation is limited. Of the two key approaches in renegotiation, namely bargaining-based negotiation and offer generation--based negotiation, the latter approach is the most promising due to its ability to generate optimized multiple-offer SLA parameters within one round during renegotiation.

A utility-based approach for customised cloud service selection

The fact that cloud computing is widely accepted results in an increasing number of cloud providers. Customers are now burdened with the task of deciding which provider to choose for serving their requirements. This work developed a broker-based framework capable of automatically selecting cloud services based on user-defined requirement parameters and the service level agreement (SLA) attributes of the cloud providers. The goal is to help customers make clever decisions to achieve their best benefit. The framework contains components for decision making, cloud monitoring, user authentication, cloud access and SLA management. More specifically, we developed a utility-based, dynamic and flexible matching algorithm capable of maximising the users' profits. The matching algorithms as well as the entire framework were evaluated using a realistic simulation environment. Experimental results show that our utility-based approach performs well in terms of the matching quality and cost-saving.

CSLAT: an SLA template for cloud service management

Service level agreements (SLAs) are used to bind cloud provider for providing services and hence to assure cloud consumer that delivered services are up to the mark. However, most of the cloud SLAs are either static in nature or are concerned only for availability of service leaving major concerns such as performance, security, metering and monitoring, automation, and many more. In this paper, we have reviewed the existing SLA frameworks and then examined their suitability in the context of cloud computing. Next, we discuss the desirable components, which should be considered in cloud SLA. Also, we have identified different parameters that need to be incorporated in each component. Based on this, we put forward a cloud SLA template, which we termed as cloud service level agreement template (CSLAT). This work attempts to provide a clear and formal definition of decisive parameters in cloud computing. The definition will give clear perception of how these parameters should be specified in SLA, so as to avoid any conflict rising due to ambiguity in it. Further, precise monitoring and QoS measurement can be done using the mathematical interpretations given corresponding to parameters. Thus, proposed CSLAT will help in automation of SLA management in cloud computing.

A framework to address inconstant user requirements in cloud SLAs management

Dynamically managing service level agreements (SLAs) is a non-trivial issue for both active media technology users and providers. Cloud computing is considered as one of the significant components of the rapidly emerging active media in the current era. As the technology grows rapidly, cloud computing requirements and techniques also change over time, while the current cloud SLA management methods are rigorous in terms of SLA contents updates with the technology innovation and user requirement change. In other words, public SLAs are used as templates, and when issuing a new SLA, it is necessary to map its requirements to all public SLAs. In addition, updating any consumer's SLA requires a cumbersome process of remapping their changed requirements to all public SLAs. This paper proposes a cloud computing SLA management mechanism based on the real options analysis concept to manage cloud SLAs in a dynamic manner. At the beginning, or when issuing a new SLA, the proposed framework receives a new user's requirements and maps these to all public SLAs, while executes only the most appropriate SLA based on options analysis and records/marks the other related solutions (SLAs) for future analysis to address any further change due to internal/external factor. This also provides a mechanism to effectively counter uncertainty parameters triggering dynamic change in cloud SLA management. The framework was deployed using Web SLA and Java followed by an experimental study to evaluate the efficacy and scalability of the proposed framework. The results show that the proposed framework provides efficient and scalable cloud SLA management mechanism.

Toward SLA-constrained service composition: An approach based on a fuzzy linguistic preference model and an evolutionary algorithm

In a market-oriented service computing environment, both back-end SLA (service level agreement) offers and front-end SLA requirements should be considered when performing service composition. In this paper, we address the optimization problem of SLA-constrained service composition and focus on the following issues: the difficulties related to preference definition and to weight assignment, the limitation of linear utility functions in identifying preferred skyline solutions, and the efficiency and scalability requirements of the optimization algorithm. We present a systematic approach based on a fuzzy preference model and on evolutionary algorithms. Specifically, we first model this multi-objective optimization problem using the weighted Tchebycheff distance rather than a linear utility function. We then present a fuzzy preference model for preference representation and weight assignment. In the model, a set of fuzzy linguistic preference terms and their properties are introduced for establishing consistent preference order of multiple QoS dimensions, and a weighting procedure is proposed to transform the preference into numeric weights. Finally, we present two evolutionary algorithms, i.e., single_EA and hybrid_EA, that implement different optimization objectives and that can be used in different SLA management scenarios for service composition. We conduct a set of experimental studies to evaluate the effectiveness of the proposed algorithms in determining the optimal solutions, and to evaluate their efficiency and scalability for different problem scales.

Benchmarking cloud performance for service level agreement parameters

Infrastructure as a Service (IaaS) Clouds offer capabilities for the high-availability of a wide range of systems, from individual virtual machines to large-scale high performance computing (HPC) systems. But it is argued that the widespread uptake for such systems will only happen if Cloud providers, or brokers, are able to offer bilateral service level agreements (SLAs). In this paper, we discuss how to measure and use quality of service (QoS) information to be able to predict availability, quantify risk, and consider liability in case of failure. We demonstrate through this work that there is a pressing need for such an understanding and explore a set of benchmarks that offers an interesting characterisation of resource performance variability which can be quite significant. We subsequently identify how such information might be used both directly by a user and indirectly via a Cloud Broker in the automatic construction and management of SLAs which reference certain kinds of financial portfolios.

AutoSLAM – A policy‐based framework for automated SLA establishment in cloud environments

SummaryCloud computing offers a realization of SOA in which IT resources are dynamically provisioned as services to consumers using flexible provisioning and pricing models. When provisioning such services, providers and consumers must first agree over the service usage terms and conditions, which are captured in Service Level Agreements (SLAs). In this paper, we propose a policy‐based framework with corresponding models, mechanisms and tools for the automated establishment of SLAs in open, diverse and dynamic cloud environments. The Automated SLA Management framework allows entities to specify their requirements and capabilities, and preferences over them in a flexible and expressive manner. It also supports multiple interaction models for SLA establishment, giving consumers and providers the flexibility to select the one that is most appropriate in a given context, while simultaneously participating in multiple concurrent SLA interactions using different interaction models. As part of the framework, we define a formal model for the underlying policies, a corresponding physical model WS‐SLAM that extends WS‐Policy and a reference architecture that can be easily implemented. We validate the practicability of our framework through the Smart CloudPurchaser prototype that can automatically purchase computing resources from Amazon EC2 under different scenarios and contexts. Copyright © 2013 John Wiley & Sons, Ltd.

Active SLA 기반 서비스 수준 협약의 자동화

Abstract As demand for IT services increase, which are based on SOA and cloud computing, service level agreements (SLAs) have received more attention in the parties concerned. An SLA is usually a paper contract written in natural language. SLA management tools which are commercially available, implement SLAs implicitly in the application with a procedural language. This makes automation of SLA management difficult. It is also laborious to maintain contract management systems because changes in a contract give rise to extensive modifications in the source code. We see the source of the trouble is the existence of documentary SLAs (paper contracts) and corresponding executable SLAs (contracts coded in the procedural language). In this paper, to resolve the current SLA management problems we propose an active SLM (Active Service Level Management) system, which is based on the active SLA (Active Service Level Agreement). In the proposed system, the separated management and processing of dual SLAs can be unified into a single process with the introduction of active SLAs (ASLAs).

A framework for SLA management in cloud computing for informed decision making

In cloud computing, service providers offer cost-effective and on-demand IT services to service users on the basis of Service Level Agreements (SLAs). However the effective management of SLAs in cl...

Cloud resource provisioning and SLA enforcement via LoM2HiS framework

SUMMARYCloud computing represents a novel on‐demand computing technology where resources are provisioned in compliance to a set of predefined non‐functional properties specified and negotiated by means of service level agreements (SLAs). Currently, cloud providers strive to achieve efficient SLA enforcement strategies to avoid costly SLA violations during application provisioning and to timely react to failures and environmental changes. These strategies include advanced application deployment mechanisms and appropriate resource monitoring concepts. In terms of cloud resource monitoring, providers tend to adopt existing monitoring tools, such as those from grid environments. However, those tools are usually restricted to locality and homogeneity of monitored objects, are not scalable, and do not support mapping of low‐level resource metrics (e.g., system uptime and downtime) to high‐level application‐specific SLA parameters (e.g., system availability). In this paper, we present a novel low‐level metrics to high‐level SLA (LoM2HiS) framework for managing the monitoring of low‐level resource metrics and mapping them to high‐level SLAs and an application deployment mechanism for scheduling and provisioning applications in clouds. The LoM2HiS framework provides the application deployment mechanism with monitored information and SLA violation prevention techniques, thereby ensuring the performance of the applications and thus increasing the revenue of the cloud provider by avoiding SLA violation penalty cost. This framework is the building block of the Foundations of Self‐governing ICT Infrastructures project, which intends to facilitate autonomic SLA management and enforcement. Thus, the LoM2HiS framework detects future SLA violation threats and can notify the knowledge component to act so as to avert the threats. We discuss in detail the conceptual design of the LoM2HiS framework and the application deployment mechanism including their implementations. Finally, we present our evaluation results based on a use‐case scenario demonstrating the usage of the LoM2HiS framework in a real cloud environment. Copyright © 2012 John Wiley & Sons, Ltd.

ANALISA BEST PRACTICE SERVICE LEVEL MANAGEMENT (SLM) CISCO MENGGUNAKAN KRITERIA KELENGKAPAN DARI THOMAS SCHAAF

Service Level Agreement (SLA) is an important document to facilitate IT service provisioning by clearly defined Quality of Service (QoS) parameters. The management of SLA is the main subject in the discipline of Service Level Management (SLM) . SLM is very important to improve relationship between IT service provider and its customer. It delivers documented agreement as a common understanding of expectation and possible achievements to the agreed cost. It means SLM builds the interface between an IT organization and its cust omer, so it plays a critical and important role in the context of IT service management. In this paper, an SLM best practice from CISCO will be analyzed with the assessment criteria of SLM framework by Thomas Schaaf. The result will be followed with several suggestion to fulfil the gap in this CISCO’s best practice.

A Compendium on Service Oriented Architecture and Service Level Agreements

ABSTRACT Service Oriented Architecture provides an effective application integration and on-demand services provision. It supports loose coupling structure of the services which provides effective service management and also effective usage of the existing services. SOA gives strong support to business Innovation if implemented properly with proper understanding of the Principles of SOA. In order to incorporate the effective SOA, there should be a thorough deployment of the SOA, the SLA metrics needs to be standardized and focused. Since, the reliability of any service depends on the successful functionality. This article studies and reviews on a broad spectrum the Service Oriented Architecture and its Service Level Agreement (SLA) and its basic metrics. Keywords SOA, SLAs of SOA, Metrics of SLA in SOA, SLA Mon Tools 1. INTRODUCTION The SOA is an application architectural concept that defines the use of services to support business requirements. In SOA, the resources are made available as independent services, which can be accessed in a standardized manner. The Services are loosely coupled in order to facilitate the usage of the existing services and the components are reusable. In SOA environment, the Service Level Agreement (SLA) refers to mutually agreed understandings and expectation focused as the evaluation criteria for Quality of Service, between the Service Provider and Service Consumers. As the Services become more flexible, the Quality of Services becomes more critical and important. Every user is concerned about the Quality of Service. Thus there is a huge necessity of defining the QoS Metrics during the contract between the Service Providers and the Service Consumers, which would prove useful in making the Service transaction execute smoothly and efficiently [1]. More and more Services are done in order to create larger business process and services with the SOA developments [2], [3]. This initiates a closer examination of the quality of the services. The traditional mechanism makes it difficult to adapt to the complexity in open networked environment. The SLA is the contractual basis between the customer and the Service Provider about the Product. The Service of SOA is managed by SLA hence the Service Management can be achieved by the effective SLA management. In a Complex network environment requirements of end-to-end Quality of Service are different. The use of SLA guarantees in product can make the network more customer-focused. Further SLA based services are becoming a requirement to the provisioning of IP based network services to ensure Quality of Service. The Technical component of SLA is made up of a number of negotiated Service Level Objectives (SLO) which is based on Key Performance Indicators (KPI) metrics and Key Quality Indicators (KQI).

Optimal IT Service Availability: Shorter Outages, or Fewer?

High enterprise IT service availability is a key success factor throughout many industries. While understanding of the economic importance of availability management is becoming more widespread, the implications for management of Service Level Agreements (SLAs) and thinking about availability risk management are just beginning to unfold. This paper offers a framework within which to think about availability management, highlighting the importance of variance of outage costs. The importance of variance is demonstrated using simulations on existing data sets of revenue data. An important implication is that when outage costs are proportional to outage duration, more but shorter outages should be preferred to fewer but longer, in order to minimize variance. Furthermore, two archetypal cases where the cost of an outage depends non-linearly on its duration are considered. An optimal outage length is derived, and some guidance is also given for its application when the variance of hourly downtime costs is considered. The paper is concluded with a discussion about the feasibility of the method, its practitioner relevance and its implications for SLA management.

SLA-BASED JOB SUBMISSION AND SCHEDULING WITH THE GLOBUS TOOLKIT 4

High performance computing is nowadays mostly performed in a best effort fashion. This is surprising as the closely related topic of grid computing, which deals with the federation of resources from multiple domains in order to support large jobs, and cloud computing, which promises seemingly infinite amounts of compute and storage, both offer quality of service (QoS), albeit in different ways. Long-term service level agreements (SLAs), which require the establishment of SLAs long in advance of their actual usage, seem a promising way for the offering of QoS guarantees in an HPC environment in a way that is not disruptive to the business models employed today. This work uses the long-term SLA approach as a basis for the provisioning of service levels for HPC resources and presents an SLA management framework to support this. Flexibility is provided by providing SLAs with different service levels, support for which is integrated into job submission and scheduling. The SLA management framework can, on a high level, be used in a generic fashion and an implementation is presented that is evaluated against a motivating scenario.

Special section: software architectures and application development environments for Cloud computing

Special section: software architectures and application development environments for Cloud computing

A dependency‐aware ontology‐based approach for deploying service level agreement monitoring services in Cloud

SUMMARYCloud computing offers virtualized computing elements on demand in a pay‐as‐you‐go manner. The major motivations to adopt Cloud services include no upfront investment on infrastructure and transferring responsibility of maintenance, backups, and license management to Cloud Providers. However, one of the key challenges that holds businesses from adopting Cloud computing services is that, by migrating to Cloud, they move some of their information and services out of their direct control. Their main concern is how well the Cloud providers keep their information (security) and deliver their services (performance). To cope with this challenge, several service level agreement management systems have been proposed. However, monitoring service deployment as a major responsibility of those systems have not been deeply investigated yet. Therefore, this paper shows how monitoring services have to be described, deployed (discovered and ranked), and then how they have to be executed to enforce accurate penalties by eliminating service level agreement failure cascading effects on violation detection. Copyright © 2011 John Wiley & Sons, Ltd.

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.

An Appropriate Violation Detection Scenario for Service Level Agreements Based on WS-Agreement Protocol

Nowadays relations between service providers and customers are set in the service level agreement templates. SLA sometimes is called as service level warranty helps to reach to a common vision about the service, quality of service warranty, priorities, responsibilities and etc in which parties agrees on it. The most important topic in service level agreement is survey management and violation detection in the provisions of SLA. In this paper we have used WS-Agreement protocol which provides standard templates for SLA management in order to design and model an appropriate workflow scenario and required subsystems regarding to Violation management in Service Level agreements. Then in this paper we add evaluation phase for completed violations of service level agreement management and then evaluation phase modeling in eTom architecture.