Selection of Trusted Service Providers by Enforcing Bayesian Analysis in iVCE

The initiative of internet-based virtual computing environment(iVCE) aims to provide the end users and applications with a harmonious,trustworthy and transparent integrated computing environment which will facilitate sharing and collaborating of network resources between applications.Trust management is an elementary component for iVCE.The uncertain and dynamic characteristics of iVCE necessitate the requirement for the trust management to be subjective,historical evidence based and context dependent.This paper presents a Bayesian analysis-based trust model,which aims to secure the active agents for selecting appropriate trusted services in iVCE.Simulations are made to analyze the properties of the trust model which show that the subjective prior information influences trust evaluation a lot and the model stimulates positive interactions.

VirtMan:design and implementation of a fast booting system for homogeneous virtual machines in iVCE

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 Open Stack.In our 100-server testbed,VirtMan boots up 1000 VMs(with a 15 GB 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.

一种基于聚类的虚拟计算环境资源聚合方法

作为面向互联网资源共享的虚拟计算环境的实例,iVCE(Internet based virtual computing environment)for Memory致力于解决广域分布的内存资源的共享与综合利用问题.由于内存资源的特殊性,传统的资源管理方法很难适用.以iVCE for Memory作为背景,提出一种基于聚类的虚拟计算环境资源聚合方法,有效降低了资源聚合的问题规模;借鉴物理学中的力场和势能理论,建立了实现资源聚合的基本模型和力场-势能模型以及相应的分布式算法;通过基于真实网络拓扑的模拟,对两种模型和算法分别进行了评估和验证.

虚拟计算环境中的可扩展分布式资源信息服务

基于网络资源的"成长性"、"自治性"和"多样性",近年来,人们提出以通用DHT(distributed Hash table)信息服务的形式实现网络资源信息的发布和查询.然而,现有的资源信息服务在通用性、易用性和自适应性等方面仍存在不足.针对虚拟计算环境iVCE(Internet-based virtual computingen vironment)的资源聚合需求,提出构建可扩展的分布式资源信息服务SDIRIS(scalable distributed resource information service).首先,提出采用自适应DHT(adaptive FissionE,简称A-FissionE)底层架构,以对上层应用透明的方式适应不同的系统规模和稳定性;其次,基于自适应DHT提出高效的多属性区间搜索算法(multiple-attribute range FissionE,简称MR-FissionE).理论分析和模拟结果表明,SDIRIS能够高效地实现资源信息的发布与查询功能.

自组织虚拟计算环境中的组信誉机制

借鉴人类社会中的组织构造与演化机制,提出一种基于组结构的信誉机制——组信誉机制.通过组信誉评价和信誉驱动的组演化机制的结合,一方面使得信誉模型具有更好的自主元素行为刻画能力和收敛特征;另一方面,基于组演化形成的自主元素聚集能够为实现自主元素基于信誉的差异化服务奠定基础,达到激励其积极参与和可靠服务的目的.

虚拟计算环境中的覆盖网技术

互联网资源的成长、自治和多样等特性给资源的有效聚合带来了巨大挑战.通过覆盖网动态组织互联网资源并支持资源的高效搜索,是虚拟计算环境中资源按需聚合的重要途径之一.文中概述了虚拟计算环境中覆盖网技术的研究进展.针对互联网资源的成长性和自治性等特点,阐述了基于Kautz图的高效覆盖网拓扑构造方法,进而给出了适用于任意正则图的通用覆盖网拓扑构造方法;针对互联网资源的多样性等特点,提出了支持分组的覆盖网拓扑构造方法;在此基础上,阐述了基于覆盖网的高效区间搜索技术,并对覆盖网拓扑的优化方法及其它复杂搜索技术进行探讨.

虚拟计算环境下信任管理研究

可信保证体系是虚拟计算环境的基础组件。虚拟计算环境下信任管理具有不确定性和动态性特点,因此,虚拟计算环境下的可信保证体系应具备主观性、基于证据以及上下文相关性的特性。针对虚拟计算环境下虚拟共同体的服务选取以及自主元素的可信度计算的安全问题,提出了基于贝叶斯分析的信任模型。