1. AgentOS: The Agent-based Distributed Operating System for Mobile Networks Salimol Thomas Department of Computer Science Illinois Institute of Technology, Chicago

2. Distributed Mobile Computing - Wide area - Mobile Host (Laptop) - Nomadic Users - Heterogeneous Characteristics Requirements - Flexibility - Mobile Computing - Support for disconnected network - Fault tolerant - Security

3. AgentOS is the solution. It is designed to support distributed mobile computing. Foundations Capabilities Advantages - Simple and powerful distributed model - Enhances flexibility and fault tolerance - Agent based - Peer to Peer Networking - Autonomous Migration - Intelligent Routing - Disconnected Computing

4. What is Agent ? Agent is a process that can perform certain tasks Reactive : Senses changes in the environment and acts according to those changes. Autonomous: Has control over its actions. Goal Driven: is proactive Continuos: is active till its termination. Agent MobileStationary (like a conventional server)

5. It has the unique ability to transport itself from one system in a network to another Suspend execution at any point in time, transport itself to a new machine and resume execution Continuos interaction with agent’s originating source is not required Mobile Agent agent Searching different databases

6. Advantage of mobile agents Reduction in network load RPC based Agent Based

7. Support for disconnected operation

8. AgentOS architecture -Completely redesigned OS [Svahnberg, 98] -AgentOS on top of the conventional operating system [Kothari, 97] - Easy to implement - Less cost - Task/Agent based system - Offers flexibility

9. AgentOS Architecture ( contd..) [Svahnberg, 98]

10. AgentOS Architecture (contd..) AgentOS on top of the Conventional operating system Examples: Aglet, Concordia etc.

11. Distributed Operating system services - Load Balancing - File System - Resource Allocation - Distributed Computing - Fault Tolerance [Chen b, 97]

12. Load Balancing A job originates at Host A Host A ask for bids from all the nodes Nodes bids Host A evaluate the bids Host A selects the best bid Host A transferred the job using an agent to the best bidder (Host D)

13. File System - Files can be made active by embedding each document in an agent - Each file agent will have its own security behavior. - File agent send updates to concerned parties and also to the backup services - Moves itself to the place where it is used most

14. Resource Allocation - Agents finds out the suitable resource - It moves closer to the resource and if possible to the device itself.

15. Distributed Mobile Computing Flexibility : Mobile Server - Client can write the service it wants. Connection less computing Conservation of bandwidth [Gray, 2001]

16. Fault Tolerance - In case of failures, the owner of the agent can be notified through event signal - Agent can migrate itself to another host - When agents migrates, it leaves behind a checkpoint of its state.

17. Security Security is a concern, however there exists security schema to prevent unauthorized, unwarranted operations - Public-Private key exchange - Digital signature - Cryptography - Encryption

18. Summary AgentOS can provide better infrastructure for distributed mobile computing Agents can enhance the qualities and capabilities of present distributed mobile computing system by providing the following services - Intelligent load balancing - Disconnected operation - Fault Tolerance - Reduced Inter-node communication

19. Application - A distributed mobile computing application was developed Platform Used OS :Windows 98 DATABASE :SQL Server 7 AgentOS : Aglet development kit (IBM) Situation A database called “weather” has daily temperature values of last 20 years. Somebody wants to calculate the average temperatures. Result set would consist of 7300 rows. The person uses his laptop to connect to the network and launch an agent. Then he gets disconnected. When he becomes online again, the agent sends him the message.

20. Agent structure Guard Agent OnCreation { launch nomad } MessageHandle { Display the result received from nomad } Nomad Agent OnCreation { dispatch( destination ) } run { get data from the database process them try sending result to Guard until success Terminate }