【作者】 何伟；

【导师】 王海洋；

【作者基本信息】 山东大学 ， 计算机软件与理论， 2009， 博士

【摘要】 随着信息技术,尤其是Internet的发展和普及,互联网早已从单纯的信息发布平台转变为支撑复杂应用和大规模业务协同的基础计算平台,这一事实正在改变着人们的社会生活及业务模式,基于Internet的分布协同成为一种趋势,在这种应用模式下,协作方式、合作伙伴规模、协作关系、应用场景、用户角色及参与方式等诸多方面正在发生重大的变化,基于网络的业务流程无处不在。首先,互联网为任何机构或个人之间的协作提供了可能,这种协作逐渐超越了业务领域、地域、数量的限制,合作伙伴规模不断扩大,相互关系变得更灵活、更开放、更自由,在现实中往往是一种无中心的关系;其次,流程应用场景由相对成熟、规范的业务应用渗透到普通用户的生活中,其特点是用户数量众多,需求的个性化特征明显,在流程建模和执行阶段,需要更为友好、自然的交互方式;再次,Internet范围内分布广泛的WEB服务资源为流程中的任务执行单元提供了更多的选择,使得基于Internet的协同应用构建方式发生了重大改变,对面向流程的网络应用产生了巨大影响和推动作用。面对Internet计算环境中业务流程应用模式的变化,传统应用模式暴露出了诸多问题。传统流程应用一般以业务分析和建模为核心,采用有中心的管理模式,虽然结构简单、易于控制,但是随着协同规模的不断扩大、协作关系变得更灵活、更自由,中心模式在应用的开放性、灵活性、可伸缩性、可扩展性等方面逐渐暴露出明显的缺陷,而这些特征对于构建Internet平台上大规模协同复杂应用具有至关重要的意义。另外,传统流程管理主要面向成熟规范的企业用户,在需求获取、业务流程分析建模、交互方式等方面提供的方法对普通用户来说并不适用。基于业务流程在当前技术和应用背景下的需求特点和应用场景的变化,本文称构建于Internet计算环境基础上的、面向流程的复杂应用为智能流程应用。该应用模式以遍布互联网的WEB服务为资源,基于服务组合动态构建以实现业务目标,支持机构或个人之间开放、灵活、自由的协同关系,适应普通用户的个性化需求,将流程嵌入到人们的日常生活中,从而改善用户参与流程的体验。本文重点围绕无中心网络计算环境下智能流程应用模式若干关键问题进行深入研究。概括地讲,无中心网络计算环境下智能流程的应用模式是:服务提供商通过本文提出的解决方案(通过下载并安装轻量级软件框架以加入无中心的智能流程虚拟网络)获得相互协同、为用户提供智能流程服务的能力,无中心的特性使得整体服务能力随着参与商家数量的扩大而不断增强,通过提供更人性化的、友好的流程服务吸引消费者,从而使服务商获得更多的商机和收益,藉此形成他们积极参与的动力;并且,这种无中心的协作关系允许服务商自由加入、退出,以确保智能流程应用更高的敏捷性和伸缩性。作为未来Internet上的新型计算模式和应用系统的核心共性支撑技术,基于无中心网络计算环境的相关技术成为近年来的研究热点,出现了大量无中心的计算模式或应用系统,包括P2P计算、网格计算以及最近兴起的云计算模型等,其共同特征是基于Internet计算环境构建具备大规模协同和服务能力的应用支撑平台,通过将资源和计算分布于成千上万的节点上而获得更强的计算力、伸缩性和灵活性。这与本文研究的无中心智能流程应用目标有相通之处,同时本文所研究的某些问题也是目前各种无中心计算模型中需要解决的共性问题。同传统流程管理技术相比,无中心模式在网络模型构建、服务评价和选择、流程调度管理、节点认证等问题上更为复杂。围绕无中心智能流程应用的目标,本文着重研究其中的若干主要问题:(1)在深入分析当前技术和应用背景下流程应用的新需求和新特征的基础上,提出无中心智能流程应用模式的整体框架,并为之建立本文研究的知识体系;(2)在允许服务节点自由加入、退出的前提下,研究一种高效的、无中心智能流程应用网络模型及其动态、自主构建方法;(3)在无中心模式没有统一评价及注册机制的情况下,研究各服务节点之间基于服务能力、服务质量、负载均衡等特征的评价方法,以此为基础,解决流程自动生成中基于服务节点评价模型的服务选择和匹配方法;(4)在流程进入执行阶段后,在不存在统一流程执行引擎或控制中心的情况下,研究流程实例如何在各服务节点的协调、调度下执行的问题;(5)从智能流程为普通用户提供更为友好、自然的交互方式的需求出发,本文还研究了流程执行过程中用户与流程服务的多通道交互问题。本文研究以近几年越来越普遍并受到商家和消费者欢迎的网上旅游为应用背景,开发原型系统实现若干主要特征,将本文研究的策略和方法应用于其中并进行检验和验证;同时,也为进一步的研究和改进奠定基础。概括来说,本文的主要创新点包括:第一,在分析当前应用背景下智能流程的特点和需求的基础上,提出一种无中心模式的智能流程应用基础框架。基于Internet和现有网络协议,本文提出一种无中心智能流程虚拟网络的概念和运行模式,该虚拟网络是通过在服务提供商的应用服务器上安装轻量级软件框架DFSP形成的逻辑网络;本文提出并设计了这一基础框架,DFSP本质上是一个有机结合了P2P网络、工作流、Web服务、Web应用等领域思想和技术的轻量级软件层,以WEB服务作为流程中任务的资源,在Internet上自主构建,形成一个无中心的智能流程虚拟网络。第二,在无中心智能流程应用框架的基础上,提出了一种兼顾节点服务能力、服务质量和负载均衡的服务节点评价方法,为服务选择和绑定提供依据。在不存在任何服务注册或节点管理中心的情况下,对服务节点的评价是一个关键问题,本文建立了基于节点能力和服务质量度量的评估模型,为保持无中心虚拟网络的均衡性,在评估中引入了节点负载均衡的度量模型,共同为流程引擎选择和绑定服务提供依据。本文详细介绍了具有随时间衰减特性的节点能力、服务质量及节点负载的度量和评估模型,并通过实验验证了服务搜索和匹配结果在各种情况下对SPN虚拟网络中节点负载均衡特性的影响。第三,针对开放、动态、无中心的网络环境,提出了服务节点在流程中的动态绑定策略,及流程实例在服务节点之间的调度和执行方法。在服务选择、绑定和执行过程中,考虑到开放的Internet环境中服务的高可变性和不确定性,本文提出了流程定义生成过程中任务与WEB服务的动态绑定策略;在流程实例执行阶段,本文深入研究了流程的实例化、调度和执行机制。第四,提出了流程实例执行过程中用户与流程服务之间的智能交互框架,使用户在流程应用中获得更好的体验。通过在无中心智能流程基础框架DFSP中增加用户上下文管理模块和多通道交互控制模块,使其能够管理并感知用户所在的上下文环境,使得智能流程服务具备与用户之间的多通道交互能力,从而将流程应用中的人机交互部分从桌面计算扩展到更为自然的环境。作为未来Internet上新型计算模式和应用系统的共性支撑技术,顺应软件工程研究和应用中将工作分散、形成全面分布式计算的趋势和商业需求,无中心网络计算环境下的智能流程应用的研究具有较高的理论价值和广阔的应用前景。本文通过对无中心智能流程网络模型动态构建、服务评价和选择、流程调度管理、节点认证、智能交互等问题的研究,建立了无中心智能流程应用的整体运行框架,提出了若干适用于无中心网络计算环境中流程管理的关键技术和方法。本文成果不仅丰富和完善了智能流程应用的理论研究,还对智能流程应用的普及推广具有一定的促进作用。更多还原

【Abstract】 With the development of Internet and related technologies, such as WEB service and SOA, Internet has changed its role from a single information promulgating platform to a computing infrastructure supporting complicated applications and massive business cooperative processes. The business modes of organizations and the lives of individuals are being changed by the above fact. And many manifest changes of business process, including scales and relationships among collaborative partners, application domains and the participating modes and roles of user, have been brought out. First, Internet provides possibilities of collaboration for any organization or individual which have exceeded the limitation of business domains, regions and amount. The relationships among collaborative partners are becoming more flexible, open and free, and sometimes there isn’ t any uniform organization in reality which is called decentralized relationships. Second, the application scenarios, which were involved in the relatively mature and regular business applications before, have also saturated into every detail of personal lives. Due to the fact of informal or individual requirements raised by these numerous users, it is impossible and unrealistic to define a universal process model for all users or design specific models for each user. The popular users would not analysis the processes and create models using specific modeling tools as the analysts or designers in enterprises. And also they need more friendly, natural and humanized interaction modes during the execution of processes. Third, the possible web services with inconsistent interfaces spreading over Internet provide more choices for the task performers in business process, which have brought out great influences and promotions to the relative technologies in process applications.Considering the new features and requirements of process applications in Internet computing environment, many problems appear in traditional business modes. Traditional process applications, usually based on business analysis and modeling, adopt center-based management mode, which has the advantage of simple construction and easiness to control. However, with the increase of collaborative scale and development of more flexible and free relationships among the business partners, centralized mode exposes obvious constraints on the features of opening ability, flexibility, refractivity and expansibility of applications, which are most important for constructing large scale collaborative complicated applications on Internet. In addition, based on definite model and normative definition, tradition process management focuses on the regular and mature users in the methods of requirements capture, process modeling and interaction modes, which are not applicable for the common users on Internet.Based on the features of requirements and the changes of scenarios in current technology and application background, this paper names the more flexible and agile, Internet-based and process-oriented complicated applications as smart process applications. In the smart process applications, with the resources of web services overspreading Internet, collaborations among decentralized organizations or individuals are supported, flexible and open environment for constructing business process are provided to realize business goals based on dynamic service composition through network and software service, and processes are embedded into users’ daily lives to improve their experiences during process execution. This paper emphasizes the research of constructing smart process applications in decentralized environments.Based on the goal of our research, the service providers spreading over Internet obtain the abilities of collaborating and providing services of smart process for users via the solution in this paper (downloading and installing a light-weighted software layer to join the decentralized smart process virtual network). The decentralized feature improves the service abilities of the whole smart process with the increasing of participating service providers, which may bring more business opportunities for them. Besides, the decentralized collaborative relationships allow service providers to join or exit freely to assure the abilities with more agilities and expansibility.Acting as the common supporting technologies for future computing modes and applications on Internet, the relative technologies based on decentralized network environments have becoming the hotspot of research in recent years. Researchers and developers have raised many computing modes, experiences and real applications, including P2P computing, network grid computing and cloud computing model, whose common characteristics are focusing on constructing supporting platform for large scale collaborative complicated applications and service abilities on Internet, and achieving good flexibility and expansibility, which has the similar goal of the research on decentralized smart process applications. At the same time, some issues in our research are the common ones to be solves in current decentralized computing models. On the other hand, compared with traditional technologies in process management, some issues are harder and more complicated, including decentralized network constructing, evaluation and selection for service peers, execution and management of process instances and peer certificating.Considering the target of decentralized smart Process model, this paper performs researches on the following important issues: Studying an efficient decentralized smart Process network logical topology and the self-constructing method based using the ideas and results in a few researching domains, such as classical Process, Web service, P2P network and pervasive computing; Investigating the evaluation of service peers based on their capabilities, qualities of services and loading; Working out the service matching and selecting methods according to the evaluation model of service peers in the automatic generation of process; Researching the issues during executing of process instances dispatched by the involved service peers; In addition, this paper also looks into the multiple interaction modes between users and their process service during the executing of process instances.On the background of e-travel increasingly accepted by providers and consumers, a prototype system with several important functionalities has been developed, which is used to validate and verify the ideas and methods in the research of this paper.In general, the main innovative points of this paper include:First, a decentralized framework for smart Process application is introduced based on the analysis of the new requirements and features of current business processes.Based on Internet and existing network protocols, this paper brings forward the concept and executing mechanism of a decentralized virtual network for smart process, as well as a light weighted software layer (called DFSP, Decentralized Framework of Smart Process) constructing the virtual network by installed on the hosts of Internet service providers. DFSP is designed in this paper, which constructs a smart Process virtual network without any center on Internet by combining the important ideas and technologies in several domains, such as workflow, web service, P2P and pervasive computing, using the web services published by providers as available resources via introducing them into the DFSP framework with minor cost.Second, a service matching and selecting method considering the capabilities, qualities of services and loading of service peers.This paper establishes the evaluation model based on the capabilities and qualities, as well as loading degree to keep the balance of the decentralized SPN network, which provides the basis of selecting and binding services for process engine.Third, According to the features of decentralized SPN network and process execution environment, this paper introduces a dynamic service binding strategy, and then researches the issues during the execution of process instances dispatched by the involved service peers.Next, this paper also proposes an interaction infrastructure with multiple modes between users and their process service during the executing of process instances.Through adding user context management module and multiple modes controlling model, the DFSP framework has the capabilities of extending the interactions between users and their process service to more natural environments from desktop computing.Acting as the common supporting technologies for future computing modes and applications on Internet, as long as acclimating the trends and requirements of decentralizing work to form full distributed computing in the development of software engineering in recent years, there are great theoretic values and expansive application foreground in the research of decentralized smart process modes. Through the study of some critical issues, including dynamic constructing of decentralized smart process network, evaluation and selection of services, scheduling and execution of process instances and peer certificating method for service peers multi-level exception handing in smart process, we build the whole structure present some key technologies and algorithms for decentralized smart process. The productions of this paper not only enrich and consummate the theoretical foundations of smart process, but also promote smart process applications.更多还原