随着云计算的普及,软件即服务(software as a service,SaaS)逐渐成为云计算的一种重要表现形式.云中数据节点的缓存是提高多租户应用数据访问性能的一种重要资源,缓存资源的共享和分配受到SaaS提供商的关注.对SaaS提供商而言,如何在多...随着云计算的普及,软件即服务(software as a service,SaaS)逐渐成为云计算的一种重要表现形式.云中数据节点的缓存是提高多租户应用数据访问性能的一种重要资源,缓存资源的共享和分配受到SaaS提供商的关注.对SaaS提供商而言,如何在多租户间有效地分配数据节点上的缓存资源,从而满足租户的服务水平协议(service level agreement,SLA),获得更高的收益已成为一项挑战.为此,提出了多租户云数据存储缓存管理机制,以实现服务提供商收益最大化的目标,结合SLA收益模型,评估不同缓存策略下服务提供商获取的收益值,将全局缓存管理问题定义为目标优化问题,并结合缓存分配特点,采用优化的遗传算法解决该问题.通过实验比较,该方法能保证SaaS服务提供商在多租户间有效利用缓存资源获取高收益.展开更多
针对云中软件即服务(Software as a Service,SaaS)多租户共享存储模式下恶意服务提供商伪造、删除或篡改租户定制存储的数据副本数据问题,结合多租户数据共享存储特点以及租户间隐私与隔离需求,提出了面向租户的多副本完整性保护机制(Te...针对云中软件即服务(Software as a Service,SaaS)多租户共享存储模式下恶意服务提供商伪造、删除或篡改租户定制存储的数据副本数据问题,结合多租户数据共享存储特点以及租户间隐私与隔离需求,提出了面向租户的多副本完整性保护机制(Tenant-oriented duplication integrity checking scheme,TDIC).TDIC通过对租户副本元组进行周期性随机抽样的方式,来降低验证对象的生成代价.为适应租户数据的动态更新,建立面向租户多副本辅助验证结构(Tenant duplication authentication structure,TDAS),TDAS可以将每个数据节点上不同租户的副本验证信息隔离,保证租户副本验证过程的隔离性.结合租户元组的同态标签与TDAS,TDIC可以在不泄露租户数据内容的前提下,委托可信第三方对租户副本进行抽样检查.分析表明,如果租户逻辑视图中包含一万个数据元组时,在元组破坏率为1%的情况下发现数据被破坏的随机抽样数目最大约为元组总数的5%,相对全部验证的方法有效降低了系统资源消耗.展开更多
为解决SaaS(Software as a Service)应用中多租户重复定制造成的数据冗余存储问题,提出一种基于元数据的差异数据存储方法。该方案研究传统元数据驱动的存储模式,通过对元数据的分类定义,给出差异存储方案的形式化语义和数据存储策略。...为解决SaaS(Software as a Service)应用中多租户重复定制造成的数据冗余存储问题,提出一种基于元数据的差异数据存储方法。该方案研究传统元数据驱动的存储模式,通过对元数据的分类定义,给出差异存储方案的形式化语义和数据存储策略。最后分别对增删改查操作提出该方案的数据访问算法。计算表明,差异存储方法在冗余减少的概率分析下显示出较高的存储空间利用效率,有效地减少了租户的冗余存储。同时性能测试结果还反映出该方案具有较好的数据访问性能。展开更多
Legacy system migration to the cloud brings both great challenges and benefits, so there exist various academic research and industrial applications on legacy system migration to the cloud. By analyzing the research a...Legacy system migration to the cloud brings both great challenges and benefits, so there exist various academic research and industrial applications on legacy system migration to the cloud. By analyzing the research achievements and application status,we divide the existing migration methods into three strategies according to the cloud service models integrally. Different processes need to be considered for different migration strategies, and different tasks will be involved accordingly. The similarities and differences between the migration strategies are discussed, and the challenges and future work about legacy system migration to the cloud are proposed. The aim of this paper is to provide an overall presentation for legacy system migration to the cloud and identify important challenges and future research directions.展开更多
In the middle of current financial crisis,measures have to be undertaken by working with fine user experience to alleviate the difficulties faced by every software corporation.Combining the CRM model with traditional ...In the middle of current financial crisis,measures have to be undertaken by working with fine user experience to alleviate the difficulties faced by every software corporation.Combining the CRM model with traditional SaaS mode,customers have little time and money in purchasing and deploying software resources. Meanwhile,developers will gradually improve the system according to user experience and feedback; besides,provide users with personalized service to obtain users' satisfaction and loyalty.The ultimate goal is to gain considerable profits for these companies to tide over the period of financial crisis.展开更多
文摘随着云计算的普及,软件即服务(software as a service,SaaS)逐渐成为云计算的一种重要表现形式.云中数据节点的缓存是提高多租户应用数据访问性能的一种重要资源,缓存资源的共享和分配受到SaaS提供商的关注.对SaaS提供商而言,如何在多租户间有效地分配数据节点上的缓存资源,从而满足租户的服务水平协议(service level agreement,SLA),获得更高的收益已成为一项挑战.为此,提出了多租户云数据存储缓存管理机制,以实现服务提供商收益最大化的目标,结合SLA收益模型,评估不同缓存策略下服务提供商获取的收益值,将全局缓存管理问题定义为目标优化问题,并结合缓存分配特点,采用优化的遗传算法解决该问题.通过实验比较,该方法能保证SaaS服务提供商在多租户间有效利用缓存资源获取高收益.
文摘为解决SaaS(Software as a Service)应用中多租户重复定制造成的数据冗余存储问题,提出一种基于元数据的差异数据存储方法。该方案研究传统元数据驱动的存储模式,通过对元数据的分类定义,给出差异存储方案的形式化语义和数据存储策略。最后分别对增删改查操作提出该方案的数据访问算法。计算表明,差异存储方法在冗余减少的概率分析下显示出较高的存储空间利用效率,有效地减少了租户的冗余存储。同时性能测试结果还反映出该方案具有较好的数据访问性能。
基金supported by National Natural Science Foundationof China(No.61262082)Key Project of Chinese Ministry of Education(No.212025)+2 种基金Inner Mongolia Science Foundation for Distinguished Young Scholars(No.2012JQ03)Inner Mongolia Natural Science Foundation of Inner Mongolia(No.2011MS0911)Postgraduate Scientific Research Innovation Project of Inner Mongolia(No.1402020201013)
文摘Legacy system migration to the cloud brings both great challenges and benefits, so there exist various academic research and industrial applications on legacy system migration to the cloud. By analyzing the research achievements and application status,we divide the existing migration methods into three strategies according to the cloud service models integrally. Different processes need to be considered for different migration strategies, and different tasks will be involved accordingly. The similarities and differences between the migration strategies are discussed, and the challenges and future work about legacy system migration to the cloud are proposed. The aim of this paper is to provide an overall presentation for legacy system migration to the cloud and identify important challenges and future research directions.
基金Supported by the National Key Technology R & D Program under Grant No.2008BAH24B03Zhejiang Provincial Natural Science Foundation of China under Grant No.Y1080130+1 种基金Zhejiang Province Key Technology R & D Program under Grant No.2008C01060-5Ningbo City Key Technology R & D Program under Grant No.2008B10023
文摘In the middle of current financial crisis,measures have to be undertaken by working with fine user experience to alleviate the difficulties faced by every software corporation.Combining the CRM model with traditional SaaS mode,customers have little time and money in purchasing and deploying software resources. Meanwhile,developers will gradually improve the system according to user experience and feedback; besides,provide users with personalized service to obtain users' satisfaction and loyalty.The ultimate goal is to gain considerable profits for these companies to tide over the period of financial crisis.
