Study Of Itinerary Graph Based On Task Blocks Of Migrating Instance

The Migrating Workflow is a novel trend in the area of the workflow management research recently. It is particularly suitable for the distributed business processes in which the huge data need to be frequently transmitted and many remote service procedures need to be frequently referenced. A framework was proposed in the document [2] for the migrating workflow management system, which is composed of three key factors, that is, migrating workflow management engine, MI (MI), and workplace. MI is the main execution agent of workflows. The management engine is in charge of the definition of workflow procedure, the generation of MI and the coordination of many MIs, and so on. The workplace refers to the anchorage server and working-machine network associated to the server while the anchorage server is the executing place of MI.According to the complexity of goal of the business process, the workflow is mapped to one or more MIs. In the model of migrating workflow, the MI during its execution is interpreted as the combination of the illustration of the static workflow, local rules and strategies, and the effect of users' decision-making. Every MI is corresponding to a single business sub-process with an relatively independent goal and complete one or more tasks with local services and resources in one workplace. Multi MIs complete the whole business by migrating and cooperation with the support of anchorage server. If the current workplace cannot afford the further task execution, MI will migrate, bringing along the task specification, itinerary graph and previous execution results, to another workplace for continuous execution.Business process is described by the procedure definition file, which contains each activity, logical relationship between activities and relative data. The MI analyses executing a business process means that it analyses the logical relationship and workplace which can be executed at, migrate among multi anchorages according to migrating strategy till the goal is reached. So the definition of the task, logical relationship, and itinerary graph become essential of the migrating strategy, which makes out the best migrating path and ensures that the MI can complete its task accurately and efficiently.In the above migrating workflow management system referenced framework, the paper presents research on migrating strategy based on the itinerary graph on task piece, according to the migrating workflow conceptual model, and based on workflow modeling and interface definition by WFMC and the core technology of mobile agent. With the strategy, the MI can feel about the environment change, react on it and change the migrating path by itself. Therefore, the fail migrating which may be caused by network's interrupt during the migrating, and the migrating will become more reliable.This strategy makes out the best migrating path in advance to improve the executive efficiency, and considers adequately the characteristic of the workflow. The execute in task is instead of task piece which includes a piece of sequential tasks that can be executed at the same workplace. This can decrease the times of migrating. One side, it can reduce the cost for migrating in or out of workplace, the other, it can avoid failure of migrating and internet attack. The core of the strategy is the partition of task pieces and the static generation and dynamic change of the itinerary graph. The goal of the strategy is improving efficiency and security of the system..The analysis of the execution results of the prototype shows that the migrating workflow system prototype realizes the designation objects correctively and efficiently, proves the correctness of this strategy.