Research On Temporal Management For Business Workflow In The Cloud Environment

In recent decades,with the rapid development of e-commerce and e-government industries,the requirement for business process automation and execution efficiency is becoming more stringent,and various business workflow systems have also emerged.The most obvious feature in business workflow application scenarios is that a large number of workflow instances are executed concurrently,and each workflow instance corresponds to a business request process.To pursue stronger processing power,high scalability and low cost,more and more business workflow systems are gradually migrated to cloud platform,and cloud infrastructures are used to ensure the effective execution of large-scale workflow instances.However,under the multiple influences of cloud computing performance instability and competing computing resources between concurrent workflow instances,some activities may have time delays during the execution process.If activity time delays cannot be prevented in time,a large number of concurrent workflow instances is unable to respond in a timely manner,which can reduce user satisfaction and even lead to huge economic losses.It can be seen that time indicator has an important impact on the service quality of business workflow systems.To ensure the timely completion of business workflow and improve the quality of service for workflow systems,it is necessary to carry out research on temporal management.Based on the above discussion,the main research work and innovations of this thesis are summarized as follows(1)The construction of temporal consistency verification model for business workflow.To monitor and verify the temporal state during the execution process of business workflow,this thesis constructs corresponding temporal consistency verification models from two different perspectives.In terms of business workflow,a temporal consistency verification model based on throughput and delay propagation effect is constructed.In terms of workflow activities executed on the same queuing system,a temporal consistency verification model based on activity response time is constructed for activities executed on a single queuing system.The proposed temporal consistency models can accurately reflect the temporal state during the execution process of workflow.(2)The design of dynamic temporal violation checkpoint selection strategy for business workflow.The selection of checkpoint is to select some time points during the execution process of workflow,and then verify the temporal state of business workflow according to the temporal consistency model,so as to detect the occurrence of temporal violation.Compared with the existing checkpoint selection strategy based on fixed observation time interval,this thesis proposes a checkpoint selection strategy based on dynamic observation time interval,which uses the workflow execution statue of the previous detection time point to determine the size of the next observation time interval.This strategy can not only effectively monitor the occurrence of temporal violation,but also reduce the monitoring cost of temporal violation.(3)The proposal of temporal violation handling strategy for business workflow.To ensure the on-time completion of a large number of concurrent workflow instances,aiming at the temporal violations detected at checkpoints,this thesis proposes a new temporal violation handling strategy.This strategy is divided into two steps.First,a temporal violation handling method based on activity time redundancy in queuing system is designed to select the appropriate processing point,which has been proved theoretically to satisfy the sufficiency and necessity properties.Then,the execution of subsequent activities in queuing system with temporal violations are accelerated by adding cloud service resources.This strategy can effectively reduce the processing cost of temporal violation while meeting the target temporal quality of service.In summary,this thesis mainly studies three aspects of temporal management problem for business workflow systems in the cloud computing environment.First,the temporal consistency models are built to monitor and verify the workflow running temporal consistency state.Secondly,the dynamic temporal violation checkpoint selection strategy is proposed,which selects the appropriate checkpoints.Finally,a new temporal violation handling strategy is designed to ensure the on-time completion of business workflow.A series of researches have been carried out to improve the service quality of the business workflow systems,and also save a lot of temporal violation monitoring and processing costs.