Support Service Level Agreements Research Articles

The solutions to improve CSR activities for Vietnam enterprises: Evidence from Ho Chi Minh City Power Corporation (EVNHCMC)

CSR activities are very important not only to generate stakeholder attitudes and behaviors but also, over the long run, to build corporate/brand image, strengthen stakeholder–company relationships, and enhance stakeholders’ advocacy behaviors for the enterprises. By analyzing the company’s current situation, managerial implementations are proposed, including in terms of CSR activities improvement via Website quality such as Customer-centric website design, Efficient current website management, regular updating of the latest information, Social network, and Customer centricity solutions by Customer Support Service Level Agreement (SLA), Organizing seminars, reality shows, expert’s advice in the electricity industry to raise customer awareness, customer responsibility in saving energy for sustainable development.

Towards decision support systems for energy management in the smart industry and Internet of Things

Decision Support Systems (DSS) have widely provided on intelligent human–machine interactions like the Internet of Things (IoT). As the dimensions and complexity of the IoT communications between intelligent devices, industrial equipment, sensors, and mobile applications are continuously increasing, supporting Service Level Agreements (SLA) for a large amount of cloud data centers and a huge number of user requests is going to be more challenging. This challenge would be more complicated when the energy consumption of the industrial IoT ecosystems increases exponentially as well. Therefore, DSS models are required for automated decision-making in critical IoT environments like intelligent industrial systems and smart cities. This paper provides a comprehensive review of the DSS strategies for energy-efficient IoT applications in intelligent urban computing. The main objective of this review is (1) presenting a technical taxonomy to categorize existing energy-efficient DSS models for industrial and smart environments in IoT ecosystems; (2) recognizing significant research trends in the field of energy-aware DSS strategies for intelligent urban computing in IoT and (3) presenting a technical and statistical analysis of reviewed studies and evaluation factors. Finally, innovations as forthcoming issues and new challenges of energy-based DSS strategies for intelligent urban computing in IoT are presented.

Energy aware cloud‐edge service placement approaches in the Internet of Things communications

SummaryIn recent years, applying Internet of Things (IoT) applications has significantly increased to facilitate and improve quality of human life activities in various fields such as healthcare, education, industry, economics, etc. The energy aware cloud‐edge computing paradigm has developed as a hybrid computing solution to provide IoT applications using available cloud service providers and fog nodes for the smart devices and mobile applications. Since the IoT applications are developed in the form of several IoT services with various quality of service (QoS) metrics which can deploy on the cloud‐edge providers with different resource capabilities, finding an efficient placement solution as one of challenging topics to be measured for IoT applications. The service placement issue arranges IoT applications on the cloud‐edge providers with various capabilities of atomic services though sufficient different QoS factors to support service level agreement (SLA) contracts. This paper presents a technical analysis on the cloud‐edge service placement approaches in IoT systems. The key point of this technical analysis is to identify substantial studies in the service placement approaches which need additional consideration to progress more efficient and effective placement strategies in IoT environments. In addition, a side‐by‐side taxonomy is proposed to categorize the relevant studies on cloud‐edge service placement approaches and algorithms. A statistical and technical analysis of reviewed existing approaches is provided, and evaluation factors and attributes are discussed. Finally, open issues and forthcoming challenges of service placement approaches are presented.

Supporting SLA via Adaptive Mapping and Heterogeneous Storage Devices in Ceph

This paper proposes a new resource management scheme that supports SLA (Service-Level Agreement) in a bigdata distributed storage system. Basically, it makes use of two mapping modes, isolated mode and shared mode, in an adaptive manner. In specific, to ensure different QoS (Quality of Service) requirements among clients, it isolates storage devices so that urgent clients are not interfered by normal clients. When there is no urgent client, it switches to the shared mode so that normal clients can access all storage devices, thus achieving full performance. To provide this adaptability effectively, it devises two techniques, called logical cluster and normal inclusion. In addition, this paper explores how to exploit heterogeneous storage devices, HDDs (Hard Disk Drives) and SSDs (Solid State Drives), to support SLA. It examines two use cases and observes that separating data and metadata into different devices gives a positive impact on the performance per cost ratio. Real implementation-based evaluation results show that this proposal can satisfy the requirements of diverse clients and can provide better performance compared with a fixed mapping-based scheme.

On building multiple spanning trees and VLAN assignment in metro ethernet networks

While most of today's research effort is being devoted to wireless technologies involving the tiniest and most sophisticated devices, Ethernet is evolving from a best effort, plug-and-play LAN technology, towards a carrier-grade WAN technology. Most of the new Ethernet standards rely on spanning tree protocols (STP) such as Rapid STP (RSTP) and multiple STP (MSTP). RSTP offers faster convergence than the legacy STP but like its predecessor, it uses a single tree to carry all the traffic offered to the network, seriously impacting throughput and bandwidth usage. MSTP however supports multiple spanning tree instances but does not provide generic methods to build those instances. Moreover, MSTP does not provide efficient methods to map between spanning trees and virtual LANs (VLAN). Operators must manually provision this mapping which seriously affects network operation expenditures and network performance. In this paper, we introduce a multiple spanning tree generation algorithm (MSTGA) and a VLAN-spanning tree mapping algorithm (VSTMA) aimed at helping operators leverage their networks, save bandwidth, and support service level agreements with their customers. These algorithms can be used to extend and/or work with MSTP. We show that MSTGA maximizes throughput while VSTMA minimizes bandwidth usage. We also show that combining edge-disjoint spanning trees with VSTMA constitutes the best bandwidth/throughput tradeoff. © 2012 Wiley Periodicals, Inc. NETWORKS, 2013

Network-aware service placement and selection algorithms on large-scale overlay networks

Currently many service providers offer their services on a private and proprietary hard- and software infrastructure. These infrastructures often share many similarities. Hence we believe a generic service management architecture, that allows service providers to offer a large array of different services on a single infrastructure or multiple providers to offer their services cooperatively, would provide many advantages over current silo-based approaches. Additionally, by allowing the distributed service management components to cooperate in a peer-to-peer overlay network, scalability and resilience of the system could be greatly improved. In this paper we propose an optimal algorithm, based on an integer linear programming (ILP) formulation, and several heuristics to support such a generic overlay-based service management architecture. More specifically, we propose algorithms for dynamically allocating server and network resources to a set of services and selecting a suitable service instance for each client. Service instances are placed on a set of servers, taking into account server resource constraints (e.g. CPU and memory). Unlike existing algorithms for this problem, those proposed in this paper also support service level agreements (SLAs), which take the form of Quality of Service demands such as transmission latency constraints and bandwidth requirements. The optimisation goal is to maximise the percentage of satisfied demand (answered requests) and minimise the total number of required overlay servers, while satisfying the SLAs and resource constraints. Additionally, we propose an extension that allows the algorithms to find overlay routing paths to improve the transmission latency for latency-sensitive services. Extensive simulations were performed to evaluate the performance and scalability of the heuristics. They showed that in many cases the heuristics perform close to optimal and they scale well in terms of network size.

A recovery mechanism for errors caused by a late subjob in a system handling SLA-based Grid workflows

Supporting SLAs (Service Level Agreements) for Grid-based workflows requires providing mechanisms for handling errors (i.e., the failures of subjobs). In the context of this paper, we propose an er...

Dynamic Bandwidth Allocation for Supporting Dynamic Service Level Agreements in EPON

Recently, Ethernet Passive optical networks (EPON) is being deployed widely as the next generation broadband access networks due to the convergence of low cost Ethernet equipment and low cost fiber infrastructure. Because of the use of shared transmission media between all users, an efficient dynamic bandwidth allocation (DBA) is necessary to enable the quality of service (QoS) in EPON. However, to receive guaranteed QoS, end users first have to sign the contract called Service Level Agreement (SLA) with service provider in which specifies the QoS performances of the provider has to promise as well as the obligations the end users have to obey. Therefore, the central issue of QoS support in EPON is the appropriate dynamic bandwidth allocation scheme that makes sure the SLAs can be exactly fulfilled. According to the negotiation fashions, the SLA can be static or dynamic. Based on current standardized EPON architecture, most studies of the DBA schemes have only focused on achieving static SLAs, and the DBA for dynamic SLAs is rarely discussed. This paper firstly addresses this issue with an extension of EPON framework that supports dynamic SLAs negotiation, and further proposes a dynamic bandwidth allocation (DBA) scheme to fulfill the dynamic SLAs. Detailed simulation experiments are also conducted to study the performance and validate the effectiveness of the proposed solution.

Self-adaptive middleware: Supporting business process priorities and service level agreements

This paper deals with quality of service, defined at the application level, with respect to business constraints expressed in terms of business processes. We present a set of adaptive methods and rules for routing messages in an integration infrastructure which yields a form of autonomic behavior, namely the ability to dynamically optimize the flow of messages in order to comply with SLAs according to business priorities. EAI (Enterprise Application Integration) infrastructures may be seen as component systems that exchange asynchronous messages over an application bus, under the supervision of a processflow engine that orchestrates the messages. The QoS (Quality of Service) of the global IT system is defined and monitored with SLAs (Service Level Agreements) that apply to each business process. The goal of this paper is to propose routing strategies for message handling that maximize the ability of the EAI system to meet these requirements in a self-adaptive and self-healing manner, i.e., its ability to cope with sudden variations of the event flow or temporary failures of a component system. These results are a first contribution towards deployment of autonomic computing concepts into BPM (Business Process Management) architectures. This approach marks a departure from previous approaches in which QoS constraints are pushed to the lower level (e.g., the network). Although the techniques, such as adaptive queuing, are similar, managing QoS at the business process level yields more flexibility and robustness.