Scenario Based Interaction Model for a Mobile Agent System Sadia Ashraf, Naveed Ejaz, Adnan A Farooqui, Kashif Zareef, Sajid Minhas Department of Computer Science Military College of Signals Rawalpindi – 46000 (National University of Sciences and Technology - PAKISTAN)

Outline Mobile Agents & their Applications The Scenario What's an interaction model Proposed Architecture Conclusion

Mobile Agent “an agent is an encapsulated computer system situated in some environment and capable of flexible, autonomous action in that environment in order to meet its design objectives” Agents are autonomous Agents have clear interfaces and well defined goals Have sensors and effectors Agents are reactive as well as pro-active A mobile agent is epitomized by the fact that in addition to above traits it also has the ability to migrate

Mobile Agent Mobile agents offer a number of advantages in comparison to traditional distributed computing paradigms… Low bandwidth consumption Persistence Fault tolerance Scalability Asynchronous These are certain characteristics of mobile agents which make these more suitable in a number of situations as compared to traditional distributed computing models.

Scenario: Stationary Demand and Purchase System Stationary Demand Collector NUST HQ 1. Agent Dem_Collector created at the NUST HQ Agent 2. Agent migrated to Host MCS Agent 3. Working at MCS MCS EME Agent 4. Agent migrated to Host NIIT Agent NIIT

Modeling the Agent Interaction Model Failure Model Security Model

Interaction Model Study of how communication (information flow) and coordination (synchronization and ordering of activities) takes place between the various processes involved in a system? Modeling the system around the interactions requires specifying an interaction protocol the set of actors and their composition

Proposed Architecture Mobile Agent Agent Host

Proposed Architecture A mobile agent is a serializable object Passport - identification number Itinerary List - List of all hosts that the mobile agent needs to visit Data - Required by the agent for its execution. Also the data that the agent collects from the various hosts during its life cycle Code Event Handlers - executed in case of errors Goals and Status Information - The tasks that the mobile agent needs to perform and their status Log File - To log all of their actions Log File Goals and Status Information Event Handlers Code Data Itinerary List Agent Passport Its data and state are marshaled (flattened and encoded) so that it can be sent from one host to another On the destination host, the object is deserialized with its execution state restored to when it was serialized The object can then resume execution on the newly arrived host

Proposed Architecture: Mobile Agent Outside World Authentication Module Data Collection Module Error Handling Module Itinerary Module Communication Module Data Placement Module Registration Module Coordinator

Proposed Architecture: Agent Host

Proposed Architecture: Agent Host Authentication Service Registration Event Manager Serialization and De - serialization Module Agent Execution Environment Transport Communication Layer Agent Manager Server Resources Outside World

Proposed Architecture: Life Cycle Un - marshalling Authentication Registration Obtaining Resource Handlers Execution Accessing Resources Events Registration and Notification Marshalling Arrival Migration Departure

Concluding Remarks We divided the agent and the agent host into a number of principal constituents. This subdivision lends the following properties to the proposed architecture: Parallelism Configurability Reusability

Concluding Remarks The agent based system has been studied purely from the perspective of interactions involved between the various components of the system. Security and failure concerns are not handled as they were out of the scope of this paper.

Concluding Remarks The main advantage of looking at an agent based system in this perspective is that it identifies the key components or the actors needed in the system. Once these actors have been identified the type of communication that takes place between these actors can be easily ascertained. This leads to the type of protocol or communication rules which should be followed by the parties engaged in the communication. Hence, overall reducing the complexity involved in understanding multifaceted distributed systems.

The End Questions ?