Agent Based Transaction System

CS790: Dr. Bruce Land

Sanish Mondkar

Sandeep Chakravarty

What are mobile agents ?

• A mobile agent is an active object that can move both data and functionality (code) to multiple places within a

distributed system. • Mobile agents are defined in formal terms as objects that

have behavior, state, and location

• The set of events varies a bit from model to model, but the following is a list of the most common ones:

Creation, Disposal, Dispatch, Arrival, Communication

Why mobile agents?

• There are several applications where the mobile agents paradigm can be used successfully solve existing problems. The following is a cross-section of possible problems:

User passivity/data timeliness Multi-staged/multi-processed

calculations Untrusted collaborators

Low-reliability/partially-disconnected networks

Project Objectives

• To make a framework for mobile agents which would allow agents to move from node to node and execute at each node

• To incorporate security features so that agent activities are securely conducted

• To make the framework fully customizable so that a user can create his/her own agents as easily as creating applets and still use the facilities provided by the agent framework

• To study existing architectures for distributed systems and investigate the possibility of how an agent-based system can solve some of the inherent problems suffered by existing systems.

• To create a sample application that uses some of the features provided by the agent framework to do something useful.

Applet Vs Agents

• Applets do not carry state

• Applets are instantiated by the receiving client

• Applets do not travel to multiple hosts

Problem Areas

• Transportation

• Authentication

• Secrecy

• Standardization

Design for Agent Host

• AgentServer

• AgentSpawner

• IncomingRequestMonitor

• RequestServicer

Design for Agent

• Agent is a purely abstract class having some method declaration. Users wishing to write their own agents will have to:

1. Inherit their customized agent from the abstract class Agent and implement all the methods

2. The main agent task will have to be put in a method called run. This is the method which shall be called by each receiving host while starting the agent thread.

Agent Transfer Protocol

• Establish connection

• Send agent identity

• Receive result object

• Send agent

• Close connections

Security Issues

• Authentication

• Controlling agent activity

• User option for agent acceptance

Security:Our Implementation

• Digital Signatures

• Message Digests

• User option for agent acceptance

• Possible extension to SSL

Sample Application

• Bill Agent

• Transfer Agent

• Info Agent

Other Approaches

• IBM Aglets WorkBench

• Java RMI

Future Work...

• A layer of security can be added by using SSL for the agent transfer

• More study is needed to understand the feasibility of having an agent-based system

• AI algorithms can be used for making mobile agents equipped with negotiation capabilities

Future Work…contd.

• For Electronic Commerce applications, there should be a mechanism by which a agent should be able to pay for the services used.

• More work is needed to make the Agent Host more robust in handling various agents

• Agents need more error handling capabilities. In case an agent dies during a task, then the sender should be informed of the failed transaction

Conclusion

• Agent systems for groupware

• Existing problems are solved eg. Webcrawlers

• Network bandwidth optimally utilized