1. In Distributed Systems
Mobile Agents
In Distributed Systems
Luk Stoops VUB - programming laboratory

2. What is a Software Agent User View
An agent is a program that assists people and act on their behalf
Agents function by allowing people to delegate work to them

3. What is a Software Agent System View
Software object situated in an execution environment
mandatory properties
Reactive
Autonomous (control over its own actions)
Goal driven (pro-active)
Temporally continuous

4. What is a Software Agent System View
Possible properties
Communicative
can communicate with other agents
Mobile
can travel from one host to an other
Learning
adapts in accordance with previous experience
Believable
appears believable to the end-user

5. Stationary Agent Executes only on the system where it begins execution
Gets information from other resources via
Remote Procedure Call
Object Request Broker (CORBA)

6. Mobile Agent Not bound to the system where it begins execution
Ability to transport itself form one system to another
Ability to travel allows him to move to a system that contains an object with which the agent wants to interact

7. Reduce the Network Load

8. Example Aglets

9. Finger

10. Overcome Network Latency
Critical real-time systems
robots in manufacturing processes
Agents dispatched from central controller
Act locally

11. Encapsulate Protocols
Protocols that implement the input /output conversions are hard-coded in the host
As protocols evolve (security, efficiency) they become a legacy problem
Mobile Agents can move to remote hosts in order to establish “channels” based on proprietary protocols

12. Execute Asynchronously and Autonomously

13. Adapt Dynamically
Sense their execution environment and react autonomously to changes
Multiple mobile agents can distribute themselves among the hosts to form the optimal configuration for solving a particular problem x y u v
(x+y) * (u+v)

14. Naturally Heterogeneous
Network computing is fundamentally heterogeneous
hardware
software
Mobile agents are computer- and transport layer independent
Optimal conditions for seamless system integration

15. Robust and Fault-tolerant
Able to react dynamically to unfavorable situations and events
If a host is being shut down, all agents executing on that machine will be warned and give time to dispatch and continue their operation on another host in the network

16. Applications Electronic commerce Personal Assistance Secure brokering
agent to agent negotiation
Personal Assistance
schedule a meeting
Secure brokering
involved parties are invited on a secure host
Distributed information retrieval
search engine to remote sources

17. Applications Telecommunication networks services
dynamic network reconfiguration
Workflow applications and groupware
Monitoring and notification
Information dissemination
internet “push” model
Parallel processing
mobile agent can clone themselves

18. Literature http://www.acm.org/~danny http://www.trl.ibm.co.jp/aglets