Showing papers on "Service-level agreement published in 2004"

Web services on demand: WSLA-driven automated management

Abstract: In this paper we describe a framework for providing customers of Web services differentiated levels of service through the use of automated management and service level agreements (SLAs). The framework comprises the Web Service Level Agreement (WSLA) language, designed to specify SLAs in a flexible and individualized way, a system to provision resources based on service level objectives, a workload management system that prioritizes requests according to the associated SLAs, and a system to monitor compliance with the SLA. This framework was implemented as the utility computing services part of the IBM Emerging Technologies Tool Kit, which is publicly available on the IBM alphaWorksTM Web site.

Service level agreement and provisioning in optical networks

Abstract: This article proposes a service level agreement applied to the optical domain (O-SLA), which is expected to be the near- and long-term network technology of the great bandwidth capacity offered by optical devices. After an exposition of the rationale behind an optical SLA, parameters that could be included in this O-SLA, as well as their values for four classes of services are proposed. Different client (wavelength or subwavelength) and service types (from leased wavelength to bandwidth on demand) are distinguished when necessary. The last part of this article presents issues related to the provisioning of services emanating from this O-SLA.

Adaptive correlation of service level agreement and network application performance

Abstract: Methods, apparatuses and systems directed to adaptive monitoring of network application performance. In one implementation, the present invention improves processes used by enterprises to track, manage, and troubleshoot performance of network applications across distributed networks. In one implementation, the present invention allows for a network application performance monitoring scheme that tracks end-to-end performance of selected network applications on a passive basis, while selectively engaging more invasive (synthetic) approaches to tracking performance and troubleshooting issues when needed.

System and method for supporting transaction and parallel services across multiple domains based on service level agreenments

Abstract: An on-demand manager provides an improved distributed data processing system for facilitating dynamic allocation of computing resources among multiple domains based on a current workload and service level agreements. Based on a service level agreement, the on-demand manager monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration, the on-demand manager determines additional resources needed to handle the workload. If the service level agreement violations cannot be handled by reconfiguring resources at a domain, the on-demand manager sends a resource request to other domains. These other domains analyze their own commitments and may accept the resource request, reject the request, or counter-propose with an offer of resources and a corresponding service level agreement. Once the requesting domain has acquired resources, workload load balancers are reconfigured to allocate some of the workload from the requesting site to the acquired remote resources.

WS-Negotiation: an overview of research issues

Abstract: A Web service is defined as an autonomous unit of application logic that provides either some business functionality or information to other applications through an Internet connection. Web services are based on a set of XML standards such as Simple Object Access Protocol (SOAP), Universal Description, Discovery and Integration (UDDI) and Web Services Description Language (WSDL). In particular, Web services discovery is the process of finding most appropriate Web services providers needed by a Web services requestor. One of the important issues in the discovery process is for Web services providers and Web services requestors to negotiate and find a solution that is acceptable to both sides. Thus, a more sophisticated business model with negotiation feature is required for this challenging research area. As there are increasing demands for negotiation technologies in the context of Web services, this paper proposes an independent declarative XML language called WS-Negotiation for Web services providers and requestors. In general, WS-Negotiation contains three parts: negotiation message, which describes the format for messages exchanged among negotiation parties, negotiation protocol, which describes the mechanism and rules that negotiation parties should follow, and negotiation decision making, which is an internal and private decision process based on a cost-benefit model or other strategies. This paper also presents a service level agreement (SLA) template model with different domain specific vocabularies for supporting different types of business negotiations in WS-Negotiation.

Specification of Service Level Agreements: Problems, Principles and Practices

Abstract: Software intensive systems (SIS) increasingly influence the ability of enterprises to be competitive in continuously changing market situations. The integration of these systems into organizations, and in particular the subsequent exploitation, maintenance and service activities, have become of utmost importance. Unfortunately the area of exploitation and operation, also known as service management, is still rather immature. Service management covers services such as performance and availability support, end-user and help desk support, education, and maintenance. One of the main concepts of service management is the Service Level Agreement (SLA). The goal of an SLA is to bridge the gap between service provider and users or customers. However, there exist many problems and unsolved questions regarding the specification and the quantification of SLAs. This paper addresses the specification of SLAs on the basis of three well-founded service management principles, respectively: ‘continuity in service management,’ the pit/shell principle of a service, and the principle of specifying the quality of both a service process and a service object. Finally, the paper addresses the validation of these principles in practice.

System and method for supporting transaction and parallel services in a clustered system based on a service level agreement

Abstract: A server allocation controller provides an improved distributed data processing system for facilitating dynamic allocation of computing resources. The server allocation controller supports transaction and parallel services across multiple data centers enabling dynamic allocation of computing resources based on the current workload and service level agreements. The server allocation controller provides a method for dynamic re-partitioning of the workload to handle workload surges. Computing resources are dynamically assigned among transaction and parallel application classes, based on the current and predicted workload. Based on a service level agreement, the server allocation controller monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration the server allocation controller determines additional resources needed to handle the current or predicted workload. The server cluster is reconfigured to meet the service level agreement.

Apparatus and method for allocating resources based on service level agreement predictions and associated costs

Abstract: A method, apparatus, and computer instructions for allocating resources based on predictions of service level agreement (SLA) breaches in order to minimize costs are provided. With the method, apparatus, and computer instructions, a prediction that an SLA will be breached is received from a prediction engine associated with the SLM system. Based on a prediction that an SLA will be breached, a minimum cost analysis is performed to determine if computer resources may be shifted from another service consumer under another SLA to facilitate the service consumer of the potentially breached SLA in order to reduce the cost of the penalty associated with breaching SLAs. If so, resources are reallocated in order to minimize penalties associated with SLA breaches.

Business driven prioritization of service incidents

Abstract: As a result of its increasing role in the enterprise, the Information Technology (IT) function is changing, morphing from a technology provider into a strategic partner. Key to this change is its ability to deliver business value by aligning and supporting the business objectives of the enterprise. IT Management frameworks such as ITIL (IT Infrastructure Library, [3]) provide best practices and processes that support the IT function in this transition. In this paper, we focus on one of the various cross-domain processes documented in ITIL involving the service level, incident, problem and change management processes and present a theoretical framework for the prioritization of service incidents based on their impact on the ability of IT to align with business objectives. We then describe the design of a prototype system that we have developed based on our theoretical framework and present how that solution for incident prioritization integrates with other IT management software products of the HP OpenviewTM management suite.

Dynamic core provisioning for quantitative differentiated services

Abstract: Efficient network provisioning mechanisms that support service differentiation are essential to the realization of the Differentiated Services (DiffServ) Internet. Building on our prior work on edge provisioning, we propose a set of efficient dynamic node and core provisioning algorithms for interior nodes and core networks, respectively. The node provisioning algorithm prevents transient violations of service level agreements (SLA) by predicting the onset of service level violations based on a multiclass virtual queue measurement technique, and by automatically adjusting the service weights of weighted fair queueing schedulers at core routers. Persistent service level violations are reported to the core provisioning algorithm, which dimensions traffic aggregates at the network ingress edge. The core provisioning algorithm is designed to address the difficult problem of provisioning DiffServ traffic aggregates (i.e., rate-control can only be exerted at the root of any traffic distribution tree) by taking into account fairness issues not only across different traffic aggregates but also within the same aggregate whose packets take different routes through a core IP network. We demonstrate through analysis and simulation that the proposed dynamic provisioning model is superior to static provisioning for DiffServ in providing quantitative delay bounds with differentiated loss across per-aggregate service classes under persistent congestion and device failure conditions when observed in core networks.

Towards Service Level Agreement Based Scheduling on the Grid

Abstract: The orchestration of complex workflows on the Grid is emerging as a key goal for the Grid community. It is necessary for these workflows to be executed reliably, respecting any dependences; it is also desirable for the user to know (albeit approximately) when the workflow will complete. The authors argue that meeting these goals will necessitate a major shift in the underlying scheduling technology, which is ultimately used to execute any computational tasks contained

CM/sup 3/: service level agreement

Abstract: To be able to provide support to the customers in their daily operation, one must not only have an efficient support process, but also an agreement on the types and quality of the services to be provided. Such an agreement is usually called service level agreement (SLA). In this paper, we suggest an SLA model and show how it is realised within four organisations in Sweden. Our model is called CM/sup 3/: SLA, and is part of a major model called CM/sup 3/: SLA/OLA.

Management of service level agreements for composite Web services

Abstract: Method and apparatus are disclosed for managing at least one service level agreement (SLA) associated with at least one composite Web service. For each completed process instance, the status data logged in executing the process instance is analyzed to determine whether the process instance satisfied the SLA. The violation/satisfaction data and the logged status data are then used to construct an explanatory decision tree. Each node in the explanatory decision tree represents at least one attribute of the process instances, each branch from a node represents a subset of attribute values of the attribute of the node, and each leaf node indicates a probability value that process instances having attribute values consistent with the attribute values in nodes on a path to the leaf node fail to satisfy the SLA. Data that represents the explanatory decision tree may then be output to explain past violations of SLAs. Other embodiments generate a predictive decision tree that may be used in predicting whether active process instances will violate a SLAs.

Method and system of ordering provisioning request execution based on service level agreement and customer entitlement

Abstract: A solution provided here comprises receiving requests for a service from a plurality of customers, responding to the requests for a service, utilizing a shared infrastructure, and configuring the shared infrastructure, based on stored customer information. Another example of such a solution comprises: analyzing at least one provisioning request; assigning a priority to the provisioning request, based on performance data and stored customer information; configuring a shared infrastructure, according to the provisioning request and the priority; and responding to requests for services, utilizing the shared infrastructure.

An approach for quality of service adaptation in service-oriented Grids

Abstract: Some applications utilizing Grid computing infrastructure require the simultaneous allocation of resources, such as compute servers, networks, memory, disk storage and other specialized resources. Collaborative working and visualization is one example of such applications. In this context, quality of service (QoS) is related to Grid services, and not just to the network connecting these services. With the emerging interest in service-oriented Grids, resources may be advertised and traded as services based on a service level agreement (SLA). Such a SLA must include both general and technical specifications, including pricing policy and properties of the resources required to execute the service, to ensure QoS requirements are satisfied. An approach for QoS adaptation is presented to enable the dynamic adjustment of behavior of an application based on changes in the pre-defined SLA. The approach is particularly useful if workload or network traffic changes in unpredictable ways during an active session

Automating the Provisioning of Application Services with the BPEL4WS Workflow Language

Abstract: We describe the architecture and implementation of a novel workflow-driven provisioning system for application services, such as multi-tiered e-Commerce systems. These services need to be dynamically provisioned to accomodate rapid changes in the workload patterns. This, in turn, requires a highly automated service provisioning process, for which we were able to leverage a general-purpose workflow language and its execution engine. We have successfully integrated a workflow-based change management system with a commercial service provisioning system that allows the execution of automatically generated change plans as well as the monitoring of their execution.

Algorithm for Minimizing Rebate Value Due to SLA Breach in a Utility Computing Environment

Abstract: The invention described is a new and useful process for minimizing the overall rebate a provider disburses to customers when a service level agreement (SLA) breach occurs in a utility computing environment. Specifically, the process compares performance data and resource usage with the SLAs of the customers, and reallocates shared resources to those customers who represent a lesser penalty to the provider in the event of an SLA breach. The process determines which resources, used by customers representing the lesser penalty, are operating below peak capacity. The process then reallocates these under-utilized resources to those customers requiring additional resources to meet SLA thresholds. If all resources are operating at peak capacity, the process reallocates the resources to those customers whose SLAs represent a greater penalty in the event of an SLA breach as compared to those customers whose SLAs provide for a lesser penalty, thereby minimizing the total rebate due upon an SLA breach.

Method and apparatus for representing and managing service level agreement management data and relationships thereof

Abstract: Techniques are provided for representing and managing data and associated relationships. In one aspect of the invention, a technique for managing data associated with a given domain comprises the following steps. A specification of data attributes representing one or more types of data to be managed is maintained. Further, a specification of algorithms representing one or more types of operations performable in accordance with the data attributes is maintained. Still further, a specification of relationships representing relationships between the data attributes and the algorithms is maintained. The data attribute specification, the algorithm specification and the relationship specification are maintained in a storage framework having multiple levels, the multiple levels being specified based on the given domain with which the data being managed is associated. The techniques may be provided in support of service level management. In such a domain, the present invention provides techniques for representing and managing service level agreement management data using a multi-level multi-ontology metadata store and extensible service level management framework.

A Probabilistic QoS Model and Computation Framework for Web Services-Based Workflows

Abstract: Web services promise to become a key enabling technology for B2B e-commerce. Several languages have been proposed to compose Web services into workflows. The QoS of the Web services-based workflows may play an essential role in choosing constituent Web services and determining service level agreement with their users. In this paper, we identify a set of QoS metrics in the context of Web services and propose a unified probabilistic model for describing QoS values of (atomic/composite) Web services. In our model, each QoS measure of a Web service is regarded as a discrete random variable with probability mass function (PMF). We describe a computation framework to derive QoS values of a Web services-based workflow. Two algorithms are proposed to reduce the sample space size when combining PMFs. The experimental results show that our computation framework is efficient and results in PMFs that are very close to the real model.

Dynamic Service Management in Heterogeneous Networks

Abstract: Novel network architectures allow users to get specific performance guarantees via the definition of a document where QoS (Quality of Service) requirements are linked to the user traffic description. Such a document is defined SLA (Service Level Agreement), and it is a formal high level definition (user view) of characteristics for a communication service, whereas low level specification (network view) is obtained translating the SLA in a different document named SLS (Service Level Specification). Although in the case of static services the network configuration process is a well defined activity, when dynamic services come into play a more complicated scenario where SLA translation into the appropriate SLS is not a one-step and static process, but it needs an active and consistent evaluation with respect to the current situation. We claim that to make this process happen automatically, we need to have intelligent devices able to translate request specified inside SLAs in the most appropriate network configuration (by means of dynamic SLS) depending on client's current “service conditions.” In this paper we introduce a framework for distributed network management through an entity, namely AcMe (Active Mediator), which performs dynamic creation of network services in a transparent to the user fashion. A new protocol, HNMP (Heterogeneous Network Management Protocol), orchestrates all AcMe functionality. Finally, an experimental analysis is presented.

A generalized protection framework using a new link-State availability model for reliable optical networks

Abstract: This paper investigates a generalized protection framework for availability-guaranteed connection provisioning in an optical wavelength-division-multiplexed (WDM) network. Reliability is a crucial concern in high-speed optical networks. A service level agreement (SLA), which mandates high service availability even in the face of network failures must be met in provisioning a reliable connection. In this study, a new link-state-modeling mechanism is developed to form a dynamic link-state parameter called link and resource availability (LRA), which represents physical-layer availability and resource status for an optical link. Such up-to-date link-state information can be used by a standard link-state routing protocol to efficiently provision reliable connections. Based on the link-state availability model, LRA, a connection-provisioning algorithm is then proposed which can guarantee customers' availability requirements. A new generalized protection model is developed through dynamic LRA-based provisioning. Numerical results demonstrate the performance of the proposed provisioning approach to be promising.

Distributed Admission Control for QoS and SLS Management

Abstract: This article proposes a distributed admission control (AC) model based on on-line monitoring to manage the quality of Internet services and Service Level Specifications (SLSs) in class-based networks. The AC strategy covers intra- and interdomain operation, without adding significant complexity to the network control plane and involving only edge nodes. While ingress nodes perform implicit or explicit AC resorting to service-oriented rules for SLS and QoS parameters control, egress nodes collect service metrics providing them as inputs for AC. The end-to-end operation is viewed as a cumulative and repetitive process of AC and available service computation. We discuss crucial key points of the model implementation and evaluate its two main components: the monitoring process and the AC criteria. The results show that, using proper AC rules and safety margins, service commitments can be efficiently satisfied, and the simplicity and flexibility of the model can be explored to manage successfully QoS requirements of multiple Internet services.

A Probabilistic QoS Model and Computation Framework for Web Services-Based Workflows

Abstract: Web services promise to become a key enabling technology for B2B e-commerce. Several languages have been proposed to compose Web services into workflows. The QoS of the Web services-based workflows may play an essential role in choosing constituent Web services and determining service level agreement with their users. In this paper, we identify a set of QoS metrics in the context of Web services and propose a unified probabilistic model for describing QoS values of (atomic/composite) Web services. In our model, each QoS measure of a Web service is regarded as a discrete random variable with probability mass function (PMF). We describe a computation framework to derive QoS values of a Web services-based workflow. Two algorithms are proposed to reduce the sample space size when combining PMFs. The experimental results show that our computation framework is efficient and results in PMFs that are very close to the real model.

Incorporating QoS Specifications in Service Discovery

Abstract: In this paper, we extend the current approaches to service discovery in a service oriented computing environment, such as Web Services and Grid, by allowing service providers and consumers to express their promises and requirements for quality of service (QoS). More specifically, we allow service providers to advertise their services in an extended DAML-S that supports quality specifications, and we allow service consumers to request services by stating required quality levels. We propose a model here for incorporating QoS specifications and requirements in service discovery, and describe how matchmaking between advertised and requested services based on functional as well as quality requirements is supported in our model.

An SLA-oriented capacity planning tool for streaming media services

Abstract: This paper addresses the problem of mapping the requirements of a known media service workload into the corresponding system resource requirements and accurately sizing a media server cluster to handle the workload. In this paper, we propose a new capacity planning framework for evaluating the resources needed for processing a given streaming media workload with specified performance requirements. The performance requirements are specified in a service level agreement (SLA) containing: i) basic capacity requirements that define the percentage of time the configuration is capable of processing the workload without performance degradation while satisfying bounds on system utilization; and ii) performability requirements that define the acceptable degradation of service performance during the remaining, non-compliant time and in case of node failures. Using a set of specially benchmarked media server configurations, the capacity planning tool matches the overall capacity requirements of the media service workload profile with the specified SLAs to identify the number of nodes necessary to support the required service performance.

Enforcement of network service level agreements

Abstract: A service level agreement may be imposed by a service provider, such as an Internet service provider, that may include, e.g., a volume limitation and a bandwidth limitation. One or more limitations of the service level agreement may be enforced or modified in response to a triggering event. For example, a bandwidth limitation on a network subscriber may be enforced or modified based on how much data is consumed by the subscriber.

Restoration of virtual private networks with qos guarantees in the pipe model

Abstract: We propose heuristic algorithms to compute efficient restorable tunnel paths for IP Virtual Private Networks (IPVPNs). We first propose a Customer Premises Equipment (CPE) based solution to the problem and then optimize it by activating selectively few core ISP routers. We consider link cost as a function of bandwidth and loss over the link. The VPN tunnel paths are computed taking into account two parameters, the link cost and the cost of core routers that serve as end points of the tunnel. These paths we then call as Active Paths. Reliability of a VPN depends on the reliability of links in the Active path. To guarantee service quality and VPN availability to the Corporate users, seamless recovery from failures is mandatory. For the sake of survivability we propose heuristics for computing optimal backup path. We assume that the residual capacity available over the links for the VPN is sufficient to satisfy the Service Level Agreement (SLA). The problem of finding optimal paths for both Active and Backup is similar to constructing a directed steiner tree routed at source and spanning all the destinations which is NP-hard. Our heuristic algorithms provide an efficient solution to this problem with polynomial computation time.

Method for supporting transaction and parallel application workloads across multiple domains based on service level agreements

Abstract: An on-demand manager provides an improved distributed data processing system for facilitating dynamic allocation of computing resources among multiple domains based on a current workload and service level agreements. Based on a service level agreement, the on-demand manager monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration, the on-demand manager determines additional resources needed to handle the workload. If the service level agreement violations cannot be handled by reconfiguring resources at a domain, the on-demand manager sends a resource request to other domains. These other domains analyze their own commitments and may accept the resource request, reject the request, or counter-propose with an offer of resources and a corresponding service level agreement. Once the requesting domain has acquired resources, workload load balancers are reconfigured to allocate some of the workload from the requesting site to the acquired remote resources.