【摘要】：隨著Internet與Web技術(shù)的高速發(fā)展及廣泛應(yīng)用,如何從眾多的服務(wù)功能相近或相同但QoS屬性值不同的Web服務(wù)中選擇出最能滿足用戶需求的Web服務(wù),已經(jīng)成為相關(guān)領(lǐng)域的一個(gè)研究熱點(diǎn)。傳統(tǒng)的Web服務(wù)選擇技術(shù)雖然能夠滿足用戶的-般功能性服務(wù)請(qǐng)求,但是由于已有的服務(wù)選擇技術(shù)沒(méi)有充分考慮服務(wù)組件的動(dòng)態(tài)性以及服務(wù)請(qǐng)求高峰期產(chǎn)生的服務(wù)器運(yùn)行負(fù)載不均衡等服務(wù)的非功能性屬性導(dǎo)致服務(wù)不可用問(wèn)題,因此不能滿足用戶有確定服務(wù)質(zhì)量等級(jí)要求的服務(wù)請(qǐng)求。論文的核心工作就是圍繞這些問(wèn)題,使用負(fù)載感知每一服務(wù)請(qǐng)求方法以及可用性感知的服務(wù)依賴關(guān)系的建模等自適應(yīng)技術(shù),針對(duì)面向服務(wù)的應(yīng)用系統(tǒng)設(shè)計(jì)以及保證服務(wù)選擇質(zhì)量的系統(tǒng)優(yōu)化等方面作了較深入的研究。 本文的主要工作有以下4個(gè)方面： 1.提出可用性感知的服務(wù)選擇模型;本文深入研究并分析了服務(wù)選擇相關(guān)理論以及自適應(yīng)技術(shù)。對(duì)Web服務(wù)及其服務(wù)等級(jí)協(xié)議進(jìn)行建模,分析任務(wù)執(zhí)行Web服務(wù)的工作流程、描述語(yǔ)言以及其QoS屬性計(jì)算,設(shè)計(jì)了可用性感知的服務(wù)選擇模型,使任務(wù)感知服務(wù)組件的可用性。 2.基于可用性感知服務(wù)選擇模型給出可用性感知的全局最優(yōu)的服務(wù)動(dòng)態(tài)選擇算法。包括以下3個(gè)方面的解決方案： (1)負(fù)載均衡策略,解決任務(wù)執(zhí)行過(guò)程中某一服務(wù)載荷過(guò)重而引起的服務(wù)性能下降的問(wèn)題。 (2)可用性記錄評(píng)價(jià)服務(wù)方法,針對(duì)當(dāng)前Web服務(wù)組件的動(dòng)態(tài)性導(dǎo)致服務(wù)失敗的問(wèn)題,設(shè)計(jì)可用性服務(wù)組件模型,對(duì)服務(wù)組件每一次被調(diào)用執(zhí)行的完成情況進(jìn)行歷史累加記錄,并設(shè)計(jì)可用性記錄調(diào)整算法,用可用性記錄作為服務(wù)選擇時(shí)一種選擇約束條件。 (3)可用性感知的服務(wù)動(dòng)態(tài)選擇算法,基于負(fù)載均衡策略與可用性記錄評(píng)價(jià)服務(wù)方法,提出了可用性感知的服務(wù)動(dòng)態(tài)選擇算法,利用0-1整數(shù)線性規(guī)劃優(yōu)化流程,并進(jìn)行設(shè)計(jì)與實(shí)現(xiàn),通過(guò)仿真實(shí)驗(yàn)證明其有效性。 3.設(shè)計(jì)實(shí)現(xiàn)了一個(gè)支持可用性感知的的服務(wù)動(dòng)態(tài)選擇應(yīng)用原型,給出了該原型系統(tǒng)的體系結(jié)構(gòu),以及系統(tǒng)實(shí)例分析。 4.系統(tǒng)仿真實(shí)驗(yàn)與分析,對(duì)上述給出的3個(gè)算法進(jìn)行了3組仿真實(shí)驗(yàn),通過(guò)實(shí)驗(yàn),驗(yàn)證了原型系統(tǒng)DSCS可以避免服務(wù)組件動(dòng)態(tài)性對(duì)系統(tǒng)服務(wù)帶來(lái)的不利影響,并能保證在訪問(wèn)量較大時(shí)系統(tǒng)具有負(fù)載均衡的能力,較好地保證了面向服務(wù)應(yīng)用系統(tǒng)能夠?yàn)橛脩籼峁┻B續(xù)一致的服務(wù),即驗(yàn)證了本文方法的有效性。
[Abstract]:With the rapid development and wide application of Internet and Web technology, how to select the Web service which can best meet the needs of users from many Web services with similar or same service functions but different QoS attribute values has become a research hotspot in related fields. Although the traditional Web service selection technology can satisfy the user's functional service request, However, the non-functional properties of the service, such as the dynamic service component and the service load imbalance caused by the peak service request, have not been fully taken into account in the existing service selection technology. Therefore, it can not satisfy the service request that the user has defined the quality of service grade request. The core work of this paper is to use adaptive techniques such as load aware of each service request method and usability aware service dependency modeling around these problems. In this paper, the design of service oriented application system and the optimization of service selection quality are studied. The main work of this paper is as follows: 1. A usability aware service selection model is proposed, and the theory of service selection and adaptive technology are studied and analyzed in this paper. Modeling the Web service and its service level protocol, analyzing the workflow of the task executing Web service, describing language and its QoS attribute calculation, designing the service selection model of usability awareness. Make task aware of the availability of service components. 2. Based on the usability aware service selection model, a globally optimal dynamic service selection algorithm for usability awareness is presented. The solutions include the following three aspects: (1) load balancing strategy to solve the problem of service performance degradation caused by overloading of a service during task execution; (2) availability record evaluation service method. Aiming at the problem of service failure caused by the dynamic nature of the current Web service component, this paper designs a usability service component model, records the completion of each invocation of the service component, and designs an algorithm for adjusting the availability record. The availability record is used as a selection constraint in service selection. (3) A service dynamic selection algorithm based on usability awareness, which is based on load balancing strategy and availability record evaluation method. This paper presents a dynamic service selection algorithm based on usability perception. It optimizes the process by 0-1 integer linear programming, and designs and implements it. The simulation results show that the algorithm is effective. A service dynamic selection application prototype supporting usability awareness is designed and implemented. The architecture of the prototype system and the analysis of system examples are given. 4. System simulation experiment and analysis, three groups of simulation experiments on the above three algorithms are carried out. Through the experiments, it is verified that the prototype system DSCS can avoid the adverse impact of the dynamic service component on the system service. It can ensure that the system has the ability of load balancing when the traffic is large, and the service-oriented application system can provide continuous and consistent service to the user, which proves the effectiveness of the method in this paper.
【學(xué)位授予單位】：青島大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TP393.09

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本文編號(hào)：2207468