Reliable Cloud Services Research Articles

Ruminant Digestive System Based Framework for Enhancing the Reliability and Availability of Cloud

In the last decade, the substantial increase in adoption of cloud computing has transformed the IT industry. From a user's viewpoint, the practically boundless scalability, the avoidance of up-front investments, and usage based payment schemes make cloud computing a very attractive option. Presently, almost all companies and individuals are utilizing the cloud for any of their purpose. Healthcare sector also understands the major advantages of cloud services and try to utilize the cloud computing. The cloud has some challenges or issues in cloud which affects the performance of the Healthcare applications in cloud. The Reliability of cloud services and Availability of cloud resources are considered as important challenges. We have already proposed three scheduling algorithms to improve the reliability and availability of cloud resources. In this paper we propose a new hybrid scheduling algorithm fit into our RDS framework to furthermore improve the performance.

Cocktail: a service-oriented cloud storage architecture for enhancing service quality

Cloud computing is getting increasingly popular because of its various benefits. Although many free cloud storage services such as Google Drive, Dropbox, etc. are available on the internet, there exist some problems in using such services. Those public cloud storage services can be more convenient and more valuable if those problems are resolved. The first problem is the limitation of the service, such as space limit, file size limit and file type limit. Secondly, different cloud storage services provide different functions so that users may have to use multiple services simultaneously in order to fulfil their needs. The process of logging in and using multiple services might be very complicated. Thirdly, users may not be able to access or even lose their data owing to incidents such as server down, network failure, and availability problems. The goal of this research is to compose a service named Cocktail by using the service-oriented computing SOC as the fundamental design approach to solve these three problems and enhance the service quality in terms of the reliability, availability and scalability of free cloud services.

A broker framework for selecting secure cloud service provider using security risk approach

Cloud computing is a rising field providing computation resources. It represents a new paradigm of utility computing and enormously growing phenomenon in the present IT industry and economy hype. The companies which provide services to customers are called as cloud service providers. The cloud users (CUs) increase and require secure, reliable and trustworthy cloud service providers (CSPs) from the market. So, it is a challenge for a new customer to choose the highly secure provider. In this paper, we propose a broker framework that analyse and rank the cloud service providers based on measuring the risks of confidentiality, integrity and availability. This model uses a CSP rank framework for the group of cloud providers by assessing security metrics which make decision of the more secure provider among the available providers list and justify the business needs of users in terms of security and reliability.

QoS guarantee protocol based on combination of opportunistic dynamic cloud service and cooperative multimedia stream for wireless sensor networks

Abstract In real-time multimedia applications, the most problems are how to store, process, and transport the multimedia data with cloud, how to optimize the cloud platform to satisfy the user demand, as well as how to provide the quality of service (QoS) guarantees by combining cloud platform and wireless sensor networks (WSNs). To overcome these issues, the multimedia cloud was designed according to the characteristics of group of pictures (GOP), determining degree, and video frame density. The opportunistic dynamic multimedia cloud platform was proposed on the basis of the variation of packet error rate, decodable frame ratio and peak signal-to-noise ratio (PSNR) with channel quality. Then, the optimal multi-relay hierarchical cooperative multimedia transmission scheme was designed and implemented by reconstructing the cooperative multimedia stream based on the framing of GOP. For enhancing the multimedia cloud computing efficiency and decreasing the complexity of encoding and decoding of multimedia stream, we combined the opportunistic dynamic multimedia cloud platform and cooperative multimedia stream, which can also enhance the resources utilization of WSNs. Finally, the QoS guarantee protocol with the combination of opportunistic dynamic multimedia cloud platform and cooperative multimedia stream for WSNs (ODM-CM-WSN) was presented. Especially, the layered architectural model for multimedia applications and the opportunistic cooperative multimedia cloud service model were developed. The mathematical and simulation results demonstrate that the proposed QoS guarantee protocol can satisfy the various requirements of multimedia applications and provide reliable and efficient cloud services with WSNs.

FTCloudSim: support for cloud service reliability enhancement simulation

Recently, an increasing number of companies have begun to deploy their application services in the cloud. However, the cloud data centre downtime has negatively affected the quality of cloud service. Many researchers have studied the problem of cloud service reliability assurance. However, there is a shortage of tools that enable researchers to evaluate their newly proposed cloud service reliability enhancement mechanisms. To fill this gap, in this paper, we propose FTCloudSim as a reliable cloud data centre simulation system based on the basic functionalities of CloudSim. FTCloudSim provides an extensible interface to help researchers implement new cloud service reliability enhancement mechanisms. In addition, FTCloudSim can also study the behaviour of the newly proposed mechanisms. We demonstrate the capabilities of FTCloudSim by using five reliability enhancement mechanisms. The results indicate the benefits of our proposed simulation system.

A Framework for Negotiating Service Level Agreement of Cloud-based Services

Abstract Cloud-based services have become the backbone of IT industry nowadays and the promising technology that offers a commoditized service to the software, the platform and the infrastructure where they are delivered as a service. Because several providers have started to offer a vast diversity of Cloud services, Cloud customers became unable to decide whose services they should use and what is the basis for their selection. Therefore, a legal contract is necessarily needed for negotiating these both Cloud parties. This contract is referred to Service Level Agreement (SLA). A SLA negotiation between Cloud parties assists in defining the Quality of Service (QoS) requirements of critical service-based processes. In addition, the role of third party in the negotiation process that is represented in Cloud broker will recommend customers to achieve the required service efficiently when negotiating with multiple providers. Currently, there is no framework that can allow customers to evaluate Cloud offerings and rank them based on their interests. Thus it is important to have a methodology that might map the customers’ requirements referred as Service Level Objectives (SLO) with the most reliable Cloud service. In this work, we address this problem by presenting a proposed framework that intends to empower customers to evaluate and select between the different Cloud service offerings. This proposed framework aims to formalize the SLA with precise and unambiguous definition of services key performance indicators (KPIs) to support automated negotiation on the details of the agreement for both contracted parties. Our reasoning evaluation of proposed framework proved the importance of negotiation process for both Cloud parties in mapping the Cloud services with the customers’ requirements.

A fault recovery‐based scheduling algorithm for cloud service reliability

AbstractBecause of the unreliable and dynamic characteristics, cloud service failures are inevitable. It has an adverse effect on task execution and scheduling. To improve cloud service reliability, we first analyze the fault recovery mechanism, and then, cloud service failures considered in this paper are classified into unrecoverable failures and recoverable failures. By extending the traditional dynamic level scheduling (DLS) algorithm, a novel scheduling algorithm based on fault recovery mechanism named fault recovery‐based DLS algorithm is proposed to reduce the failure probability of task scheduling. The experimental results confirm that fault recovery mechanism can meet the reliability requirements of cloud computing infrastructures and the proposed algorithm can effectively ensure trustworthy execution of tasks. Copyright © 2014 John Wiley & Sons, Ltd.

Model and Analysis of Cloud Storage Service Reliability Based on Stochastic Petri Nets

HDFS is a distributed file system of Hadoop cluster, providing storage service for cloud computing. Files in HDFS are broken into block-sized chunks, each block is replicated to physically separated machines. Some studies have been conducted to HDFS, but no work focuses on the performance analysis of HDFS. In this paper, a concise mathematic tool is adopted, Stochastic Petri Nets (SPNs), to establish a system model of HDFS. By the general SPNs model, the reliability, availability and maintainability of HDFS can be measured, and a hierarchical decomposition method is proposed to avoid the state space explosion problem as well, which give a theoretical basis for further studying on the optimal reliability of cloud services.

A Trustworhty Model for Reliable Cloud Service Discovery

computing is a new model for delivering new applications and services. Its adoption is gaining ground because most of the services provided by the cloud are of low cost and readily available for use. Despite many promises by the cloud service providers, users remain much concerned about the general risk associated with the adoption of the cloud. The availability of many cloud service providers on one hand promotes competition in the cloud market and gives end users more freedom to choose the best cloud provider however it became a tedious and time consuming task for potential cloud users to evaluate and compare the available cloud offerings in the market. Hence, discovering a reliable service is a daunting task. This research proposed a trustworthy model for reliable cloud service discovery.

한국과 일본의 클라우드 서비스 인증제도 비교연구

최근 클라우드에 대한 인식이 널리 확산되면서 세계적으로 클라우드 이용이 점점 더 증가하고 있다. 클라우드는 ICT를 기반으로 하는 다양한 산업에 융 복합이 가능하고, 비용 절감 등 장점이 많아 경기 침체기인 요즘 더욱더 각광받고 있다. 그러나 클라우드 서비스의 잠재력을 더욱 더 발휘하기 위해서는 서비스 제공자와 소비자관점에서 서비스의 보안, 성능, 가용성 등 핵심 이슈들에 대한 명확한 이해가 필요하며 사용자의 주된 관심은 어떻게 안전하고 신뢰할 수 있는 클라우드 서비스를 제공받아 사용할 것인가에 맞추어지게 된다. 이러한 문제점에 대응하기 위하여 한국에서는 클라우드 서비스 인증제도가 시행되고 있으며 일본에서는 ASP-SaaS-Cloud 인증제도가 시행되고 있다. 본 연구에서는 양국의 두 인증제도의 비교분석을 수행하고 두 인증제도간의 차이점에 대하여 기술한다. 궁극적으로는 두 인증제도간의 비교연구 결과를 토대로 한국의 클라우드 서비스 인증제도의 발전방안을 제안하기로 한다. Due to the wide spread of the perception of cloud computing, the usage of cloud computing is increasing globally. Cloud computing is able to converge the various industrial domains based on ICT and it is more and more popular because it has a lot of benefits such as cost savings etc. in global economic recession. However, if cloud computing service is to achieve its potential, it is necessary to clearly understand the critical issues such as service security, performance and availability and so on from the perspectives of the providers and the consumers of the cloud service. In addition, customers focus on how to get and use the safe and reliable cloud service. In order to meet these problems, Korea cloud service certification system and Japanese ASP-SaaS-Cloud certification system were performed in each country. This paper aims at comparing and analyzing between them and describing the difference. Eventually, we propose the improvement strategy of Korea cloud service certification system based on the comparison results between them.

Implementation of User-End Broker Policy to Improve the Reliability of Cloud Services

Outage in cloud computing services is a critical issue and is primarily attributed to the single data center connectivity. To address the cloud outage, this work proposes a model for the subscription and selection of more than one data center. Selection of data center can be determined by the usage of broker at the user ends itself. Provision of broker at user's end reduces the overhead at provider's end; as a result performance of cloud data center improves. For the selection of appropriate data center, broker takes the feedback from the available data centers, and select one of them. During the selection of cloud, their status (up/down) at that particular time is also considered. In case of outage at one data center, other can be selected from the available list. Broker also facilitates the homogeneous use of cloud by allotting the load to less congested data centers. Experimental results revealed that multiple data center approach is not only helpful in countering the outage (as other data center can be selected from the broker) but also the usage cost.

Fault tolerance and QoS scheduling using CAN in mobile social cloud computing

The performance of mobile devices including smart phones and laptops is steadily rising as prices plummet sharply. So, mobile devices are changing from being a mere interface for requesting services to becoming computing resources for providing and sharing services due to immeasurably improved performance. With the increasing number of mobile device users, the utilization rate of SNS (Social Networking Service) is also soaring. Applying SNS to the existing computing environment enables members of social network to share computing services without further authentication. To use mobile device as a computing resource, temporary network disconnection caused by user mobility and various HW/SW faults causing service disruption should be considered. Also these issues must be resolved to support mobile users and to provide user requirements for services. Accordingly, we propose fault tolerance and QoS (Quality of Services) scheduling using CAN (Content Addressable Network) in Mobile Social Cloud Computing (MSCC). MSCC is a computing environment that integrates social network-based cloud computing and mobile devices. In the computing environment, a mobile user can, through mobile devices, become a member of a social network through real world relationships. Essentially, members of a social network share cloud service or data with other members without further authentication by using their mobile device. We use CAN as the underlying MSCC to logically manage the locations of mobile devices. Fault tolerance and QoS scheduling consists of four sub-scheduling algorithms: malicious-user filtering, cloud service delivery, QoS provisioning, and replication and load-balancing. Under the proposed scheduling, a mobile device is used as a resource for providing cloud services, faults caused from user mobility or other reasons are tolerated and user requirements for QoS are considered. We simulate scheduling both with and without CAN. The simulation results show that our proposed scheduling algorithm enhances cloud service execution time, finish time and reliability and reduces the cloud service error rate.

Proxy based seamless connection management method in mobile cloud computing

Nowadays, complex smartphone applications are developed that support gaming, navigation, video editing, augmented reality, and speech recognition which require considerable computational power and battery lifetime. The cloud computing provides a brand new opportunity for the development of mobile applications. Mobile Hosts (MHs) are provided with data storage and processing services on a cloud computing platform rather than on the MHs. To provide seamless connection and reliable cloud service, we are focused on communication. When the connection to cloud server is increased explosively, each MH connection quality has to be declined. It causes several problems: network delay, retransmission, and so on. In this paper, we propose proxy based architecture to improve link performance for each MH in mobile cloud computing. By proposed proxy, the MH need not keep connection of the cloud server because it just connected one of proxy in the same subnet. And we propose the optimal access network discovery algorithm to optimize bandwidth usage. When the MH changes its point of attachment, proposed discovery algorithm helps to connect the optimal access network for cloud service. By experiment result and analysis, the proposed connection management method has better performance than the 802.11 access method.

Performance evaluation of cloud service considering fault recovery

Cloud computing is a recent trend in IT, which has attracted lots of attention. In cloud computing, service reliability and service performance are two important issues. To improve cloud service re...