Mission-flow Constructor A Workflow Management System Using Mobile Agents

Developing co de for the execution of a distributed, dynamic workflow requires significant effort and hence it becomes necessary to build tools that enable the creation and execution of such workflows. Compelling arguments have been made for the implementation of workfl ow management systems using mobile agents [CGN96, MLL97]. Mobile agents are autonomous pieces of code that can migrate under their own control from one machine to another within a heterogeneous network. Mission -flow Constructor (MfC) is a workflow manageme nt system built on the D’Agents mobile agent system [GCKR96]. Like its predecessor Mobile Agent Construction Environment (MACE) [Sha97], MfC uses the concept of visual languages and further abstracts the process of building a workflow. Agents generated by MfC are small and migrate only once. These agents hence make more optimal use of network resources than those generated by MACE. MfC generated agents also use improved communication means and incorporate some basic fault tolerance mechanisms. A set of pri mitive constructs that encapsulate commonly used topologies has been defined to make easier the process of workflow definition. A workflow specified using the GUI and associated annotation process is compiled to a set of D’Agents agents by making use of th e visual depiction and the code fragments that define the individual modules. MfC then launches these agents to execute the various tasks associated with the workflow specified by the user.