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.

An Initial Approach to Explaining SLA Inconsistencies

Abstract: An SLA signed by all interested parties must be created carefully, avoiding contradictions between terms, because their terms could carry penalties in case of failure. However, this consistency checking may become a challenging task depending on the complexity of the agreement. As a consequence, an automated way of checking the consistency of an SLA document and returning the set of inconsistent terms of the agreement would be very appealing from a practical point of view. For instance, it enables the development of software tools that make the creation of correct SLAs and the consistency checking of imported SLAs easier for users. In this paper, we present the problem of explaining WS-Agreement inconsistencies as a constraint satisfaction problem (CSP), and then we use a CSP solver together with an explanation engine to check the consistency and return the inconsistent terms. Furthermore, a proof-of-concept using Choco solver in conjunction with the Palm explanation engine has been developed.

An Iterative Budget Algorithm for Dynamic Virtual Machine Consolidation Under Cloud Computing Environment

Abstract: Virtualization is a crucial technology of cloud computing to enable the flexible use of a significant amount of distributed computing services on a pay-as-you-go basis. As the service demand continuingly increases to a global scale, efficient virtual machine consolidation becomes more and more imperative. Existing heuristic algorithms targeted mostly at minimizing either the rate of service level agreement violations or the energy consumption of the cloud. However, the communication overhead among different virtual machines and the decision time of virtual machine consolidation are rarely considered. To reduce both the over-utilized nodes and the under-utilized nodes with the consideration of migration cost, communication overhead, and energy consumption, this paper presents a new iterative budget algorithm in which a budget heuristic and a multi-stage selection strategy are designed to find suitable migration objects and targets simultaneously. Experiments show that the proposed algorithm provides a substantial improvement over other typical heuristics and metaheuristic algorithms in reducing the energy consumption, the number of migrated virtual machines, the overall communication overhead, as well as the decision time.

Resource allocation algorithm for light communication grid-based workflows within an SLA context

Abstract: Service level agreements (SLAs) are currently one of the major research topics in grid computing. Among many system components for supporting SLA-aware grid-based workflow, the SLA mapping mechanism receives a prominent position. It is responsible for assigning sub-jobs of the workflow to grid resources in a way that meets the user's deadline and minimises costs. Assuming many different kinds of sub-jobs and resources, the process of mapping a light communication workflow within an SLA context defines an unfamiliar and difficult problem. This paper presents a mapping algorithm, which can cope with this problem. The quality and efficiency of the algorithm is demonstrated through performance measurements.

Error recovery mechanism for grid-based workflow within SLA context

Abstract: Service Level Agreements (SLAs) serve as a foundation for a reliable and predictable job execution at remote grid sites. In this paper, we describe an error recovery mechanism for workflow within the SLA context, coping with catastrophic failure when one or several High Performance Computing Centers (HPCCs) are detached from the grid system. We propose an algorithm to detect all affected sub-jobs when the error happens and an algorithm to remap those sub-jobs to the remaining healthy HPCCs with makespan optimise. The experiment result shows that our mechanism discovers a higher quality solution in a shorter time period than other existing methods.