Attila Kertesz

A survey on service quality description

Quality of service (QoS) can be a critical element for achieving the business goals of a service provider, for the acceptance of a service by the user, or for guaranteeing service characteristics in a composition of services, where a service is defined as either a software or a software-support (i.e., infrastructural) service which is available on any type of network or electronic channel. The goal of this article is to compare the approaches to QoS description in the literature, where several models and metamodels are included. consider a large spectrum of models and metamodels to describe service quality, ranging from ontological approaches to define quality measures, metrics, and dimensions, to metamodels enabling the specification of quality-based service requirements and capabilities as well as of SLAs (Service-Level Agreements) and SLA templates for service provisioning. Our survey is performed by inspecting the characteristics of the available approaches to reveal which are the consolidated ones and which are the ones specific to given aspects and to analyze where the need for further research and investigation lies. The approaches here illustrated have been selected based on a systematic review of conference proceedings and journals spanning various research areas in computer science and engineering, including: distributed, information, and telecommunication systems, networks and security, and service-oriented and grid computing.

An SLA-based resource virtualization approach for on-demand service provision

Cloud computing is a newly emerged research infrastructure that builds on the latest achievements of diverse research areas, such as Grid computing, Service-oriented computing, business processes and virtualization. In this paper we present an architecture for SLA-based resource virtualization that provides an extensive solution for executing user applications in Clouds. This work represents the first attempt to combine SLA-based resource negotiations with virtualized resources in terms of on-demand service provision resulting in a holistic virtualization approach. The architecture description focuses on three topics: agreement negotiation, service brokering and deployment using virtualization. The contribution is also demonstrated with a real-world case study.

An interoperable and self-adaptive approach for SLA-based service virtualization in heterogeneous Cloud environments

Cloud computing is a newly emerged computing infrastructure that builds on the latest achievements of diverse research areas, such as Grid computing, Service-oriented computing, business process management and virtualization. An important characteristic of Cloud-based services is the provision of non-functional guarantees in the form of Service Level Agreements (SLAs), such as guarantees on execution time or price. However, due to system malfunctions, changing workload conditions, hard- and software failures, established SLAs can be violated. In order to avoid costly SLA violations, flexible and adaptive SLA attainment strategies are needed. In this paper we present a self-manageable architecture for SLA-based service virtualization that provides a way to ease interoperable service executions in a diverse, heterogeneous, distributed and virtualized world of services. We demonstrate in this paper that the combination of negotiation, brokering and deployment using SLA-aware extensions and autonomic computing principles are required for achieving reliable and efficient service operation in distributed environments. ? Heterogeneous Cloud environments need business-oriented autonomic service executions. ? A novel approach called Service-level agreement-based Service Virtualization. ? Built on three areas: agreement negotiation, brokering and service deployment. ? Principles of autonomic computing are used to cope with failures in Clouds. ? Validated in a simulation environment using a biochemical application.

A taxonomy of grid resource brokers

Grid computing has gone through some generations and as a result only a few widely used middleware architectures remain. Using the tools of these middlewares, various resource brokers have been developed to automate job submission over different grids. Most of the present brokers operate only on a single grid infrastructure, where they have been developed. This taxonomy helps identifying and categorizing the most important properties of brokers within different Resource Management Systems. The result of this work reveals the differences of the examined Resource Brokers, which can enhance a more efficient grid usage and future development.

GMBS: A new middleware service for making grids interoperable

Grid resource management has been a highly studied research field since Grids were born. Though well-designed, evaluated and widely used resource brokers and meta-schedulers have been developed, new capabilities are still required, while the major demand is for interoperability support. Most of the existing brokering solutions can hardly cross the borders of current middleware systems that are lacking the support of these requirements. In this paper we (i) investigate the current resource management solutions from the lowest to the highest level of the Grid middleware, (ii) examine and compare their connections by presenting an anatomy that helps users to grasp the basics of their operation and the researchers to identify common components and open issues. Then we (iii) introduce meta-brokering, which enables higher level resource management by utilizing existing Grid brokers, and provide an implementation of this solution, the Grid Meta-Broker Service, which is a new interoperable grid middleware service for interconnecting Grid islands to compose a World Wide Grid, where users and portals can transparently utilize a growing number of Grids in the future. Finally we (iv) evaluate the presented solution in a simulated Grid environment using real workloads.

Grid meta-broker architecture: towards an interoperable grid resource brokering service

Grid computing has gone through some generations and as a result only a few widely used middleware architectures remain. Using the tools of these middlewares different resource brokers have been developed to automate job submission over different grids. As grid resources were grouped to Virtual Organizations, users seem to become isolated by these groups. Enhancing interoperability among these VOs and grids will be the main issue of future generation grids. This paper describes a metabrokering architecture that shows how to enable the interoperability of various grids through their own resource brokers.

Enhancing Federated Cloud Management with an Integrated Service Monitoring Approach

Cloud Computing enables the construction and the provisioning of virtualized service-based applications in a simple and cost effective outsourcing to dynamic service environments. Cloud Federations envisage a distributed, heterogeneous environment consisting of various cloud infrastructures by aggregating different IaaS provider capabilities coming from both the commercial and the academic area. In this paper, we introduce a federated cloud management solution that operates the federation through utilizing cloud-brokers for various IaaS providers. In order to enable an enhanced provider selection and inter-cloud service executions, an integrated monitoring approach is proposed which is capable of measuring the availability and reliability of the provisioned services in different providers. To this end, a minimal metric monitoring service has been designed and used together with a service monitoring solution to measure cloud performance. The transparent and cost effective operation on commercial clouds and the capability to simultaneously monitor both private and public clouds were the major design goals of this integrated cloud monitoring approach. Finally, the evaluation of our proposed solution is presented on different private IaaS systems participating in federations.

Autonomic SLA-Aware Service Virtualization for Distributed Systems

Cloud Computing builds on the latest achievements of diverse research areas, such as Grid Computing, Service-oriented computing, business processes and virtualization. Managing such heterogeneous environments requires sophisticated interoperation of adaptive coordinating components. In this paper we introduce an SLA-aware Service Virtualization architecture that provides non-functional guarantees in the form of Service Level Agreements and consists of a three-layered infrastructure including agreement negotiation, service brokering and on demand deployment. In order to avoid costly SLA violations, flexible and adaptive SLA attainment strategies are used with a failure propagation approach. We demonstrate the advantages of our proposed solution with a biochemical case study in a Cloud simulation environment.

Integrated Monitoring Approach for Seamless Service Provisioning in Federated Clouds

Cloud Computing offers simple and cost effective outsourcing in dynamic service environments, and allows the construction of service-based applications using virtualization. By aggregating the capabilities of various IaaS cloud providers, federated clouds can be built. Managing such a distributed, heterogeneous environment requires sophisticated interoperation of adaptive coordinating components. In this paper we introduce an integrated federated management and monitoring approach that enables autonomous service provisioning in federated clouds. In this architecture, cloud brokers manage the number and the location of the utilized virtual machines for the received service requests. In order to provide seamless service executions, a state of the art monitoring solution is proposed that supports cloud selection performed by the management layer of the architecture. Our solution is able to cope with highly dynamic service executions by federating heterogeneous cloud infrastructures in a transparent and autonomous manner.

Grid Interoperability Solutions in Grid Resource Management

Since the management and beneficial utilization of highly dynamic grid resources cannot be handled by the users themselves, various grid resource management tools have been developed, supporting different grids. To ease the simultaneous utilization of different middleware systems, researchers need to revise current solutions. Grid Interoperability can be achieved at different levels of grid systems. In this paper, we investigate interoperability issues in Grid resource management, focusing on the following approaches: 1) extending existing resource brokers with multiple middleware support; 2) interfacing grid portals to different brokers and middleware; or 3) developing a new middleware component, a meta-broker that not only interfaces various brokers but also coordinates their simultaneous utilization. We show that all of these approaches contribute to enable Grid Interoperability, and conclude that meta-brokering is a significant step towards the final solution.