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TP393; 湖南省气象局依托国家超级计算长沙中心，建立了我省第一个远程高性能计算终端用户。针对远程环境的搭建，首先分析了湖南省气象局在高性能计算方面的需求，然后从省级气象部门业务计算需求出发，重点阐述了以高性能计算机集群“天河一号”为计算资源的远程计算环境的系统架构以及主要技术路线与方法。考虑到远程高性能强大的计算能力和省级气象部门作业提交的复杂需求，又进一步设计了湖南省远程高性能任务调度的系统流程以及保障远程计算环境高速稳定的多层面方案。最后也给出了高分辨率中小尺度 WRF模式在该环境下运行的实际情况，计算速度改善非常明显。

Dynamic consolidation of virtual machines (VMs) in a data center is an effective way to reduce the energy consumption and improve physical resource utilization. Determining which VMs should be migrated from an overloaded host directly influences the VM migration time and increases energy consumption for the whole data center, and can cause the service level of agreement (SLA), delivered by providers and users, to be violated. So when designing a VM selection policy, we not only consider CPU utilization, but also define a variable that represents the degree of resource satisfaction to select the VMs. In addition, we propose a novel VM placement policy that prefers placing a migratable VM on a host that has the minimum correlation coefficient. The bigger correlation coefficient a host has, the greater the influence will be on VMs located on that host after the migration. Using CloudSim, we run simulations whose results let draw us to conclude that the policies we propose in this paper perform better than existing policies in terms of energy consumption, VM migration time, and SLA violation percentage.

Failures are normal rather than exceptional in the cloud computing environments. To improve system avai- lability, replicating the popular data to multiple suitable locations is an advisable choice, as users can access the data from a nearby site. This is, however, not the case for replicas which must have a fixed number of copies on several locations. How to decide a reasonable number and right locations for replicas has become a challenge in the cloud computing. In this paper, a dynamic data replication strategy is put forward with a brief survey of replication strategy suitable for distributed computing environments. It includes： 1） analyzing and modeling the relationship between system availability and the number of replicas; 2） evaluating and identifying the popular data and triggering a replication operation when the popularity data passes a dynamic threshold; 3） calculating a suitable number of copies to meet a reasonable system byte effective rate requirement and placing replicas among data nodes in a balanced way; 4） designing the dynamic data replication algorithm in a cloud. Experimental results demonstrate the efficiency and effectiveness of the improved system brought by the proposed strategy in a cloud.

With the development of Internet technology and human computing, the computing environment has changed dramatically over the last three decades. Cloud computing emerges as a paradigm of Internet computing in which dynamical, scalable and often virtualized resources are provided as services. With virtualization technology, cloud computing offers diverse services (such as virtual computing, virtual storage, virtual bandwidth, etc.) for the public by means of multi-tenancy mode. Although users are enjoying the capabilities of super-computing and mass storage supplied by cloud computing, cloud security still remains as a hot spot problem, which is in essence the trust management between data owners and storage service providers. In this paper, we propose a data coloring method based on cloud watermarking to recognize and ensure mutual reputations. The experimental results show that the robustness of reverse cloud generator can guarantee users’ embedded social reputation identifications. Hence, our work provides a reference solution to the critical problem of cloud security.

The Internet is undergoing a tremendous change towards the globalized computing environment. Due to the open, dynamic and uncontrollable natures of the Internet, software running in the Internet computing environment has some new features, which bring challenges to current software technologies in terms of software model, software operating platform, software engineering approaches and software quality. Researchers in China have proposed the term ＂Internetware＂ to present the emerging software paradigm. Sponsored by the National Basic Research 973 Program, several research practices have been done on the Internetware in the past decade. This paper summarizes the progress and status of the Internetware researches. A technical solution framework for the Internetware paradigm is proposed from four aspects： the Internetware software model defines what the Internetware is to be; the Internetware middleware determines how to run the Internetware applications; the engineering methodology determines how to develop the Internetware applications; the Internetware quality assurance determines how well the Internetware applications can perform. The paper also discusses the ongoing research issues and future trends of Internetware.

In order to fully utilize all potential available network resources and make the interoperability of systems possible, we propose to integrate cloud computing and peer-to-peer (P2P) computing environments together. We utilize the mobile multi-agent technology to construct an effective hierarchical integration model named Cloud-P2P. As the original management mechanisms for traditional cloud computing and P2P computing systems are no longer applicable to Cloud-P2P, we propose a novel hybrid collaborative management ring based on mobile multi-agent in order to ensure the efficiency and success rate of task implementation in the Cloud-P2P environment. This mechanism needs to divide the system into core ring, cloud inner rings and several peer rings. In each ring, every node is in collaboration with its neighbor nodes with multi-agent, or uses mobile agent moving from node to node with string or parallel methods to monitor the statuses and performances of all nodes, in order to avoid problems of performance bottleneck and single point failure. This paper analyses the node conditions of cloud computing and P2P computing environments in-depth, then elaborates on Cloud-P2P and the hybrid collaborative management ring based on mobile multi-agent (HCMRMMA). After that, the construction method of the network ring topology for Cloud-P2P is introduced. Finally, experimental results and performance analysis of HCMRMMA are presented.

Cloud computing as an emerging technology promises to provide reliable and available services on demand. However, offering services for mobile requirements without dynamic and adaptive migration may hurt the performance of deployed services. In this paper, we propose MAMOC, a cost-effective approach for selecting the server and migrating services to attain enhanced QoS more economically. The goal of MAMOC is to minimize the total operating cost while guaranteeing the constraints of resource demands, storage capacity, access latency and economies, including selling price and reputation grade. First, we devise an objective optimal model with multi-constraints, describing the relationship among operating cost and the above constraints. Second, a normalized method is adopted to calculate the operating cost for each candidate VM. Then we give a detailed presentation on the online algorithm MAMOC, which determines the optimal server. To evaluate the performance of our proposal, we conducted extensive simulations on three typical network topologies and a realistic data center network. Results show that MAMOC is scalable and robust with the larger scales of requests and VMs in cloud environment. Moreover, MAMOC decreases the competitive ratio by identifying the optimal migration paths, while ensuring the constraints of SLA as satisfying as possible.

Today’s software systems need to support complex business operations and processes.The development of the web-based software systems has been pushing up the limits of traditional software engineering methodologies and technologies as they are required to be used and updated almost real-time,so that users can interact and share the same applications over the internet as needed.These applications have to adapt quickly to the diversified and dynamic changing requirements in the physical,technological,economical and social environments.As a consequence,we are expecting a major paradigm shift in software engineering to reflect such changes in computing environment in order to better address the fundamental needs of organisations in this new era.Existing software technologies,such as model driven development,business process engineering,online（re-）configuration,composition and adaptation of managerial functionalities are being repurposed to reduce the time taken for software development by reusing software codes.The ability to dynamically combine contents from numerous web sites and local resources,and the ability to instantly publish services worldwide have opened up entirely new possibilities for software development.In retrospect to the ten years applied research on Internetware,we have witnessed such a paradigm shift,which brings about many changes to the developmental experience of conventional web applications.Several related technologies,such as cloud computing,service computing,cyber-physical systems and social computing,have converged to address this emerging issue with emphasis on different aspects.In this paper,we first outline the requirements that the Internetware software paradigm should meet to excel at web application adaptation;we then propose a requirement model driven method for adaptive and evolutionary applications;and we report our experiences and case studies of applying it to an enterprise information system.Our goal is to provide high-level guidelines to researchers and practitioners to meet the challenges of building adaptive industrial-strength applications with the spectrum of processes,techniques and facilities provided within the Internetware paradigm.

Internet-based virtual computing environment （iVCE） has been proposed to combine data centers and other kinds of computing resources on the Internet to provide efficient and economical services. Virtual machines （VMs） have been widely used in iVCE to isolate different users/jobs and ensure trustworthiness, but traditionally VMs require a long period of time for booting, which cannot meet the requirement of iVCE＇s large-scale and highly dynamic applications. To address this problem, in this paper we design and implement VirtMan, a fast booting system for a large number of virtual machines in iVCE. VirtMan uses the Linux Small Computer System Interface （SCSI） target to remotely mount to the source image in a scalable hierarchy, and leverages the homogeneity of a set of VMs to transfer only necessary image data at runtime. We have implemented VirtMan both as a standalone system and for OpenStack. In our 100-server testbed, VirtMan boots up 1000 VMs （with a 15 CB image of Windows Server 2008） on 100 physical servers in less than 120 s, which is three orders of magnitude lower than current public clouds.

This paper presents an algorithm to evaluate estimated and exact system reliabilities for a computer network in the cloud computing environment.From the quality of service（QOS） viewpoint,the computer network should be maintained when falling to a specific state such that it cannot afford enough capacity to satisfy demand.Moreover,the transmission time should be concerned as well.Thus,the data can be sent through several disjoint minimal paths simultaneously to shorten the transmission time.Under the maintenance budget B and time constraint T,we evaluate the system reliability that d units of data can be sent from the cloud to the client through multiple paths.Two procedures are integrated in the proposed algorithm-an estimation procedure for estimated system reliability and an adjusting procedure utilizing the branch-and-bound approach for exact system reliability.Subsequently,the estimated system reliability with lower bound and upper bound,and exact system reliability are computed by applying the recursive sum of disjoint products（RSDP） algorithm.