Service-level agreement

About: Service-level agreement is a research topic. Over the lifetime, 4358 publications have been published within this topic receiving 75333 citations. The topic is also known as: SLA.

System and method for enforcing communications bandwidth based service level agreements to plurality of customers hosted on a clustered web server

Abstract: A method and system for controlling and guaranteeing a service level agreement (SLA) based on a communications outbound link bandwidth usage to a plurality of customers having electronic business activity hosted by at least one server as a server farm, includes monitoring the outbound communications bandwidth usage by each customer traffic to determine a level of service being provided to each customer with respect to the agreed service level agreement in each service cycle time per unit of time. The flow of incoming requests to each customer business activity application is controlled so as to guarantee a level of service previously agreed to the customer by queuing requests to the customer and by selectively dropping requests to the customer to guarantee the agreed service levels to the customer. The controlling process controls and guarantees each outbound link usage based service level agreement by controlling the flow of incoming requests to the at least one server.

Comprehensive Explanation of SLA Violations at Runtime

Abstract: Service Level Agreements (SLAs) establish the Quality of Service (QoS) agreed between service-based systems consumers and providers. Since the violation of such SLAs may involve penalties, quality assurance techniques have been developed to supervise the SLAs fulfillment at runtime. However, existing proposals present some drawbacks: 1) the SLAs they support are not expressive enough to model real-world scenarios, 2) they couple the monitoring configuration to a given SLA specification, 3) the explanations of the violations are difficult to understand and even potentially inaccurate, 4) some proposals either do not provide an architecture, or present low cohesion within their elements. In this paper, we propose a comprehensive solution, from a conceptual reference model to its design and implementation, that overcomes these drawbacks. The resulting platform, SALMonADA, receives the SLA agreed between the parties as input and reports timely and comprehensive explanations of SLA violations. SALMonADA performs an automated monitoring configuration and it analyses highly expressive SLAs by means of a constraint satisfaction problems based technique. We have evaluated the impact of SALMonADA over the resulting service consumption time performance. The results are satisfactory enough to consider SALMonADA for SLA supervision because of its low intrusiveness.

Monitoring Dependencies for SLAs: The MoDe4SLA Approach

Abstract: In service oriented computing different techniques for monitoring service level agreements (SLAs) are available. Many of these monitoring approaches focus on bilateral agreements between partners. However, when monitoring composite services it is not only important to figure out whether SLAs are violated, but we also need to analyze why these violations have occurred. When offering a composite service a company depends on its content providers to meet the service level they agreed upon. Due to these dependencies a company should not only monitor the SLA of the composite service, but also the SLAs of the services it depends on. By analyzing and monitoring the composite service in this way, causes for SLA violations can be easier found. In this paper we demonstrate how to analyze SLAs during development phase and how to monitor these dependencies using event logs during runtime. We call our approach MoDe4SLA (monitoring dependencies for SLAs).

Systems and methods for provisioning of storage for virtualized applications

Abstract: Methods for provisioning storage for virtual machines by meeting a service level agreement (SLA) are disclosed. The SLA pertains to the operation of a virtual machine. An example of the method includes monitoring the workload of the first virtual machine; establishing at least one service level objective (SLO) in response to the observed workload; determining an SLA that meets the at least one SLO, wherein the SLA defines the time the SLO is satisfied; and provisioning at least one resource used by the first virtual machine in response to the SLA not being satisfied, wherein the provisioning causes the SLA to be satisfied.

Optimizing virtual machine placement for energy and SLA in clouds using utility functions

Abstract: Cloud computing provides on-demand access to a shared pool of computing resources, which enables organizations to outsource their IT infrastructure. Cloud providers are building data centers to handle the continuous increase in cloud users' demands. Consequently, these cloud data centers consume, and have the potential to waste, substantial amounts of energy. This energy consumption increases the operational cost and the CO2 emissions. The goal of this paper is to develop an optimized energy and SLA-aware virtual machine (VM) placement strategy that dynamically assigns VMs to Physical Machines (PMs) in cloud data centers. This placement strategy co-optimizes energy consumption and service level agreement (SLA) violations. The proposed solution adopts utility functions to formulate the VM placement problem. A genetic algorithm searches the possible VMs-to-PMs assignments with a view to finding an assignment that maximizes utility. Simulation results using CloudSim show that the proposed utility-based approach reduced the average energy consumption by approximately 6 % and the overall SLA violations by more than 38 %, using fewer VM migrations and PM shutdowns, compared to a well-known heuristics-based approach.