Research On Web Service Composition Based On QoS

Web service is being paid more and more attention as a distributed applicationtechnology. The function provided by atomic service is limited while the requirementof users is complex and polybasic. Only by combing the existing atomic services thatcan provide services that meet the user’s demands. Consequently, how to choose andorganize atomic services reasonably and efficiently to meet the requirements of usershas become a problem that needs to be solved.Due to the low efficiency of existing combination modes, WSCM-N combinationservice model is designed firstly in this paper to describe the combination modes ofWeb Service using the principle of workflow. Secondly, QoS-S calculation model isput forward to calculate QoS of atomic services according to the user’s needs ofobjective and subjective. Lastly, SA-TA algorithm is proposed according to WSCM-Nmodel and QoS-S model to calculate the QoS of Web service after combination.Measured by consumed time of calculating optimal combination planning, thecomparing of SA-TA algorithm and the Integer Programming algorithm shows that thetime consumed by SA-TA algorithm is linear with Atomic process and the quantity ofWeb service while the Integer Programming algorithm increases exponentially with it.The time consumed by SA-TA algorithm is shorter than Integer Programmingalgorithm, which demonstrates the effectiveness of proposed algorithm.