Research On Distant Communication Mechanism Of Mobile Workflow

As a concept originated to manage those fixed activities of businesses, workflow can execute and monitor these activities by dividing them into well-defined tasks, roles, rules and procedures. As a result, workflow can achieve the aim at improving the organization level of business and work efficiency, and provide an advanced method for enterprises to carry out their business goals more effectively. The appearance of mobile agent technology provides a better way to construct workflow system.Migrating workflow is a new technology applying mobile computing to workflow management. According to migrating workflow technology, several migrating instances complete workflow by migration and coordination, which are the projections of activities in workflow business procedure.Essentially, Migrating workflow is an object that looks for cooperators on behalf of a user, and cooperates with other agents in order to implement the task of the user . Therefore, communication is the essential demand of migrating instance.Communication mechanism of Migrating workflow designed mostly from the perspective of supporting mobile computing. In traditional distributed computing model, the position of Agents fixed and not changed in the whole life circle since it is created. So the message sender is easy to get the location of a target mobile agent for communication. But for a migrating instance, its position may be changed frequently, the following problems need to be considered under migrating workflow computing mode: Firstly, how to have a position independence naming method for MI in distributed environment. Second, how to implement transparent locating of a MI. Thirdly, how to handle messages that are send to MI hen it is being in the procedure of migration. Finally, how to resolve the problem of communicating invalidation. Many researchers have put forward some kind of solutions of agent location tracking, message storage and transfer for problems above, such as Broadcasting method, Link Tracing method, Home Proxy method Central Registration method, and etc. Although these methods have their advantages respectively, there are some disadvantages in tracing efficiency, expansibility and communication reliability.The work in this thesis is communication mechanism research on message transfer. An algorithm based on communication algorithm in the system is presented in this paper. In this algorithm, address registration and multicasting are used by mean s of address—book so that it is more efficient, and suitable for many kinds of patterns of migration and communication and has a better solution to the troubles with migrating instance communication. The issue of reliable communication resulting from Agent moving is studied in the paper. Based on analyzing current solutions to the issue, a mechanism called Active Communication Mechanism (ACM) is proposed, which can provide reliable and efficient communication for migrating workflow. The detailed analysis regarding the reliability and efficiency of ACM is also presented. ACM Call reliably an d efficiently deliver the sender's message to receiver allowing the free migration of both them and guaranteeing the exactly—once semantics for message deliver.This thesis went deep into the remote communication problem of migrating instance and discussed its essential technical implement, and thus provided a feasible communication mode for the application of migrating workflow system.