CSE300

Agent-1.1

Software Agents and AgletsSoftware Agents and Aglets

Kimble Cheron,Professor Steven A. Demurjian,

and Mitch Saba

Computer Science & Engineering DepartmentThe University of Connecticut

191 Auditorium Road, Box U-155Storrs, CT 06269-3155

steve@engr.uconn.eduhttp://www.engr.uconn.edu/

~steve(860) 486 - 4818

CSE300

Agent-1.2

Overview of PresentationOverview of Presentation

IntroductionIntroduction Reasons for Agent Creation Defining Agents Researchers Involved in Agent Development

Technical OverviewTechnical Overview Basic Agent Anatomy Agent Implementation (Aglets) Aglet Environment Aglet Methods

Distributed ComputingDistributed Computing Role of Agents in Distributed Computing Future Evolution of Intelligent Agent Entities

Conclusions and Future ResearchConclusions and Future Research

CSE300

Agent-1.3

IntroductionIntroduction

Age of TechnologyAge of Technology Personal PC as Common as Television

Personal Tasks Performed Using Computers

Postal Operations (Electronic Mail) Banking and Financial Operations (Electronic

Banking) Shopping News Retrieval Stock Information Updates Communication Others

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Agent-1.4

Reasons for Agent CreationReasons for Agent Creation

Majority of Above Tasks Executed Based on Majority of Above Tasks Executed Based on Direct ManipulationDirect Manipulation Nothing Occurs Unless Mouse, Keypad,

Touchpad is Used Event-Oriented Interactions with End-Users

End-UsersEnd-Users

Majority are Computer Illiterate Depend on Software to Perform Tasks Not Limited to Personal Computers, Embedded

Systems Require Operators The The Software AgentSoftware Agent is the Key to Providing a is the Key to Providing a

Delegated Approach to Direct ManipulationDelegated Approach to Direct Manipulation

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Agent-1.5

Reasons for Agent CreationReasons for Agent Creation

Potential Reduction of Network LoadPotential Reduction of Network Load Movement of Code to Remote Location Voluminous Data Remains Locally Resident

Addressing Network Latency IssuesAddressing Network Latency Issues Communication of Decision “Instantaneous” and

“Simultaneously” Real-Time Notification Issue: Eliminate Delays

Encapsulate ProtocolsEncapsulate Protocols Change Protocol, Change Agent Reactive to Evolution

Asynchronous, Autonomous, and HeterogeneousAsynchronous, Autonomous, and Heterogeneous Nature of Today’s Computing Platforms Dynamically Reactive to Change Potential for Fault-Tolerance and Robustness

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Agent-1.6

Defining AgentsDefining Agents

Agent ImplementationAgent Implementation Personal Assistance Networks Databases Operating Systems Other Equipment (Medical Equipment)

Agent FunctionsAgent Functions Find and Filter Information Customize Views of Information Automate Work Delegate Work Back to Computer

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Agent-1.7

Perspectives for DefinitionPerspectives for Definition

Two Perspectives for Defining AgentTwo Perspectives for Defining Agent User System

User PerspectiveUser Perspective of an Agent of an Agent A Software Agent is the Broker for the User Program that Allow User’s to Delegate Work to

Them Perform Work for User as Directed

System PerspectiveSystem Perspective of an Agent of an Agent An Agent is a Software Object that is Situated

Within a Working Environment and Possesses the Mandatory Agent Properties

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Agent-1.8

Agent PropertiesAgent Properties

Mandatory Properties (Can Be Classifications)Mandatory Properties (Can Be Classifications) Reactive:

Senses Changes in the Environment and Acts According to Those Changes

Autonomous: Autonomously Control Own State/Behavior Has Control Over its Own Actions

Goal-driven: Proactive to Specific User Goals

Temporarily Continuous: Constantly Executing in Runtime Environment

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Agent-1.9

Agent ClassificationAgent Classification

Communicative: Communicative: Communicate with Other Agents, Systems, and

People Learning: Learning:

An Agent Learns Based on Prior Experience or Behavior

Mobile: Mobile: Able to Transport Itself from One System to

Another Flexible: Flexible:

Actions Occur on the Fly, Not Scripted Character: Character:

An Agent Has Personality and an Emotional State

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Agent-1.10

Stationary vs. Mobile AgentsStationary vs. Mobile Agents

Stationary AgentStationary Agent: Limited to Single Node: Limited to Single Node Definition of Definition of Mobile AgentMobile Agent

An Application Capable of Migrating Across Network to Accomplish Required Tasks

Mobile Agents are Being Used for Diverse Mobile Agents are Being Used for Diverse Technologies Mentioned in Introduction SlideTechnologies Mentioned in Introduction Slide Agents are Able to Interact with Objects in a

Different System Retrieving Stock Quotes From the Internet on a

Real Time Basis Implementing Push and Pull Paradigms Electronic Marketplace and Commerce Etc...

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Agent-1.11

A Mobile Agent Travels A Mobile Agent Travels Computer to Computer Computer to Computer

Computer ComputerAgent Agent

Agent

Computer

Network

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Agent-1.12

Researchers Involved in Agent Researchers Involved in Agent DevelopmentDevelopment

Known Groups and People Responsible Known Groups and People Responsible Government Agencies

Rock Island Army Arsenal Academic Institutions

Carnegie Melon University Massachusetts Institute of Technology Stanford University University of Maryland Baltimore County

Computer Industry Companies IBM Microsoft

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Agent-1.13

Technical OverviewTechnical Overview

Basic Agent AnatomyBasic Agent Anatomy An Agent is an Object Which Has Properties

Similar to Object Oriented Classes The Agent’s Attributes are Similar to Instance

Variables Assist the Agent in Traveling, Communication, and

Recognition Each Agent (Stationary/Mobile) has Five

Properties State Implementation Interface Identifier Principals

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Agent-1.14

Agent PropertiesAgent Properties

Interface

Implementation

State

Identifier

Principals

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Agent-1.15

Properties: StateProperties: State

Definition (Analogous to Activation Record)Definition (Analogous to Activation Record) Contains All Contents and Values of the

Agent’s Runtime State and Object State Agent TravelingAgent Traveling

State Contains All the Information Required to Resume Execution After Traveling

Language DependenciesLanguage Dependencies Implementation Language Determines If an

Agent Only Uses its Instance Variables to Resume Execution

Saving the Execution State at Runtime is Not Java Compliant Java Agents Require the Object State to Resume

Execution

StateImplementationInterfaceIdentifierPrincipals

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Agent-1.16

Properties: ImplementationProperties: Implementation

DefinitionDefinition The Code Used to Execute an Agent on Any

Location (Location Independent) Agent TravelingAgent Traveling

An Agent Can Travel With its Code Code on Demand

An Agent Can Retrieve its Code After Reaching its Destination

Language DependenciesLanguage Dependencies A Common Language Must Be Used

To Allow Agent to Travel and Execute on a Different Host

Usually a Platform Independent Scripting Language is Used for Implementation

StateImplementationInterfaceIdentifierPrincipals

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Agent-1.17

Properties: InterfaceProperties: Interface

DefinitionDefinition Entity Used for Agent-to-Agent

Communication or Agent-to-System Communication

Two Styles of Communication InterfacesTwo Styles of Communication Interfaces Allows Others Access to an Agent’s Methods Messaging Interface

Allows Agents to Use a Language for Communication

Messaging Interface LanguageMessaging Interface Language Knowledge Query and Manipulation Language

(KQML) Provides Point to Point Messaging Between Agents

StateImplementationInterfaceIdentifierPrincipals

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Agent-1.18

Properties: IdentifierProperties: Identifier

DefinitionDefinition Required Entity Used for Recognition and

Locating Traveling Agents Each Agent Has its Own Unique Identifier

An Identifier is Globally Unique and Immutable Combination of Principals’ Identities and a Serial

Number Identifier FunctionsIdentifier Functions

Used for Directory Services To Refer to a Specific Agent Instance

StateImplementationInterfaceIdentifierPrincipals

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Agent-1.19

Properties: PrincipalsProperties: Principals

DefinitionDefinition Entity Used by the System to Authenticate

Access to an Agent Two Main Principals

Manufacturer (Developer of Agent) The Manufacturer is the Principal Responsible for

Creating the Agent Owner (User or Agent)

Responsible for the Legal and Moral Way in Which the Agent Will Behave (Behavior)

StateImplementationInterfaceIdentifierPrincipals

CSE300

Agent-1.20

Agent EnvironmentAgent Environment

PlacePlace Basic Environment in Which an Agent

Executes Provides the Operating System for the Agent Cannot Execute Agents Conceptually Similar to Runtime Environment,

Virtual Memory Management, Activation Rcds. Construction of a Place: Four ConceptsFour Concepts

Engine Resources Location Principals

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Agent-1.21

EngineEngine

DescriptionDescription Supplies the Energy to the Place and the Agent

to Function Provides a Link for Places and Agents to

Networks and Other Resources Provided by a Host

Hierarchical Structure of the Engine Host, Engines, Places, and Agents A Host May Hold Many Engines Engines Can Hold Many Places Places May House Many Agents

Places are Given Names Because an Engine May Places are Given Names Because an Engine May House Several PlacesHouse Several Places

EngineResourcesLocationPrincipals

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Agent-1.22

The Agent Model PyramidThe Agent Model Pyramid

Host

Engines

Places

Aglets

E E E

P P P

A A A

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Agent-1.23

ResourcesResources

DescriptionDescription Services Provided by the Host

Networks Processors and Memory Disk Databases Other Hardware and Software Services

Controlled Access to ResourcesControlled Access to Resources Provided to the Agent by the Engine and Place

EngineResourcesLocationPrincipals

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Agent-1.24

LocationLocation

DescriptionDescription Address of the Executing Agent

Construction of Location: Combination of Combination of The Name of a Place in Which It Executes The Network Address of the Engine in Which

the Place Resides Typical Written Location Typical Written Location

The Port of the Engine With a Place Name Attribute and an Internet Protocol (IP) Address

EngineResourcesLocationPrincipals

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Agent-1.25

PrincipalsPrincipals

Two Main PrincipalsTwo Main Principals Manufacturer Place Master

MManufacturer Author (Provider) of the Place Responsible for the Operation of the Place

Place MasterPlace Master Responsible for the Creation of the Place

Implementation

EngineResourcesLocationPrincipals

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Agent-1.26

Place and EnginePlace and Engine

Agents

Place

Engine

Resources

Host

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Agent-1.27

Agent BehaviorAgent Behavior

Three Agent EventsThree Agent Events Creation and Disposal Transfer Communication

CreationCreation Occurs in a Place Performed by an Agent Residing in the Same

Place Performed by an Agent or Non-agent Outside

of the Place

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Agent-1.28

Agent CreationAgent Creation

Three Steps Instantiation and Identifier Assignment Initialization Autonomous Execution

Instantiation and Identifier Assignment Step Creates the Object and Executable

Similar to the Constructor of an Object, the Class Specifies the Interface and Implementation of the Agent

A Place Will Assign the Agent its Identifier. InitializationInitialization

Initializes using Arguments Provided by Creator

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Agent-1.29

Agent CreationAgent Creation

Completion Guarantees the Agent Has Been Correctly Installed in the Place

Autonomous ExecutionAutonomous Execution The Agent Starts Execution After Installation Executes Independently of Other Agents in the

Place Disposal

Performed in a Place Accomplished by an Agent Itself, a System,

Another Agent in the Place, or an Agent or Non-agent Outside of the Place

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Agent-1.30

Agent DisposalAgent Disposal

Reasons for Disposal Lifetime Has Expired Security Rules Have Been Violated Not in Use System is Going Offline (Shutdown)

Disposal StepsDisposal Steps An Agent is Allowed to Complete All Current

Tasks Execution of the Agent is Suspended by the

Place

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Agent-1.31

Agent TravelAgent Travel

Definition Agent is Dispatched From its Origin and

Received by the Specified Destination Performed by an Agent Itself, Another Agent in

the Same Place, or an Agent or Non-agent System Outside of the Place

Origin Place and Destination Manage Travel Travel ManagementTravel Management

Origin Place Contacts Destination Place Return Failure Indication to Agent If No Contact

Destination Place Response Fulfill Travel Request Return Failure Indication to Origin

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Agent-1.32

Agent TransferAgent Transfer

Resume Execution

Deserialize Agent

Decode Data

Receive DataTransfer Data

Encode Data

Serialize Agent

Suspend Execution

Sender Receiver

Network

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Agent-1.33

Dispatching an AgentDispatching an Agent

ProcessProcess Destination Must Be Known Prior to Departure Agent Notifies the Destination Agent System It

Would Like to Depart An API is Used for Communication for

Departure Destination Agent System (Engine) Process

Request for Departure DDestination Agent System (Engine) Response

Suspend the Agent Serialize the Agent’s Data Determine the Transport Protocol for the Agent Transport the Agent

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Agent-1.34

Receiving an AgentReceiving an Agent

ProcessProcess Receiving Engine Determines to Accept or

Reject and Agent From the Sending Host Sender Must Authenticate Itself to the

Receiving Engine Receiving Engine TasksReceiving Engine Tasks

Receive the Agent Decode its Data Information Deserialize the Agent

Sets New Instantiation for the Agent Resume Agent Execution

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Agent-1.35

Agent Class TransferAgent Class Transfer

Three Methods: Dependent upon the Location of Three Methods: Dependent upon the Location of the Classthe Class Class at Destination Class at Origin Code-on-Demand

Class at DestinationClass at Destination Contained in the Engine’s Class Cache or the

Local File System No Need to Transfer Class

Transferred Agent Must Contain the Full Class Name and Discriminator May Have Information that Describes the Location

of the Class Definition

CSE300

Agent-1.36

Agent Class Transfer MethodsAgent Class Transfer Methods

Class at OriginClass at Origin Transported With the Agent’s State to the

Destination Engine State May Transferred More Than Once

Can Lead to Increased Network Traffic and Wasted Network Bandwidth

Code-on-DemandCode-on-Demand Class is Made Available by a Server Destination Engine Receives Class on a Code-

on-Demand Basis Destination Address Must Perform an

Additional Network Connection Agent Can Carry Classes on Transfer or by a Per-Agent Can Carry Classes on Transfer or by a Per-

Request BasisRequest Basis

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Agent-1.37

Agent Class TransferAgent Class Transfer

Agent Agent

Class Code Class Code

DestinationOrigin

Class Code

Server

(c) Class at Server

(b) Class at Origin (a) Class at destination

What Other Information Must be Available at Destination?

CSE300

Agent-1.38

CommunicationCommunication

Properties of Messaging CommunicationProperties of Messaging Communication Point-to-Point Messaging

One-to-One Type Messaging Broadcast Messaging

One-to-Many Type Messaging, Useful in Multi-agent Systems

Intra-Place Communication Communication With an Agent in the Same Place

Inter-Place and Inter-Engine Communication With an Agent in a Different Place

Agents Can Send Messages to Other Agents Agents Can Invoke the Methods of Other

Agents If Authorized

CSE300

Agent-1.39

Interagent CommunicationInteragent Communication

Three Inter-Agent Communication Schemes Now-Type Messaging Future-Type Messaging One-way-Type Messaging

Intra-Place, Inter-Place, and Inter-Engine Intra-Place, Inter-Place, and Inter-Engine Communication Communication

Agent Messaging ParadigmsAgent Messaging Paradigms Peer-to-Peer: Dedicated Communication Broadcast: Multi-Agent Environment

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Agent-1.40

Now-Type MessagingNow-Type Messaging

Most PopularMost Popular Most Commonly UsedMost Commonly Used SynchronousSynchronous

Blocks Further Execution Until Receiver Has Handled and Acknowledged the Message

Send and Wait Paradigm for Message Passing Classic and Easy to Model Approach

Sender Receiver

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Agent-1.41

Future-Type MessagingFuture-Type Messaging

AsynchronousAsynchronous No Blocking of Current Execution

Sender Has a Future (Handle) Sender Has a Future (Handle) Used for Obtaining Result

FlexibleFlexible Sender does not have to Wait for Receiver’s

Response Useful for Multi-Agent CommunicationUseful for Multi-Agent Communication

Sender Receiver

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Agent-1.42

One-Way-Type MessagingOne-Way-Type Messaging

AsynchronousAsynchronous No Blocking of Current Execution

Useful for Message Sending Agent that does not Useful for Message Sending Agent that does not Expect Replies from Message Receiving Agent Expect Replies from Message Receiving Agent Sender Does Not Retain a Handle Receiver Does Not Acknowledge Message

Termed Fire-and-Forget: May be Non-ReliableTermed Fire-and-Forget: May be Non-Reliable

Sender Receiver

CSE300

Agent-1.43

Agent Implementation (Aglets)Agent Implementation (Aglets)

OriginsOrigins Named for the Combination of the Two Terms

of Agent and Applet DefinitionsDefinitions

Applet: A “Lightweight Application” “Aglet”: A “Lightweight Agent”

Differences Differences Aglet

Carries It’s State Movement From One Host to the Next

Applet Only Carries It’s Class Files Along Movement Based on a Server Client Network

CSE300

Agent-1.44

Implementation LanguageImplementation Language

Implementation LanguageImplementation Language Java Was Chosen Due to the Benefits its

Provides Towards Agent Construction Movement to Java Worldwide

Benefits of JavaBenefits of Java Platform Independence Secure Execution Dynamic Class Loading Multithread Programming Object Serialization Reflection

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Agent-1.45

Agent Characteristics of Java: BenefitsAgent Characteristics of Java: Benefits

PPlatform Independent Allows an Agent to Travel and Execute on Any

Type of Computer Secure ExecutionSecure Execution

Eliminates the Option of Programs Accessing Private Objects that They Do Not Have Authorization to Use

The Environment Makes its Safe to Host an Unknown Agent

Dynamic Class LoadingDynamic Class Loading Allows Agents to Execute Independently Agents Do Not Have to Be Created During the

Main Program Execution

CSE300

Agent-1.46

Agent Characteristics of Java: BenefitsAgent Characteristics of Java: Benefits

Multithread ProgrammingMultithread Programming Agents Execute Independently of other Agents Agents can Communicate with Other Agents

Object SerializationObject Serialization During Transportation the Agent’s Data (and

Code) is Serialized and Then Deserialize ReflectionReflection

Assists Agents in Finding Out Information About Other Agents and Themselves

Types of Object Information Methods, Constructors of Loaded Classes, and

Fields Meta-Data on Active Classes that can be Queried

CSE300

Agent-1.47

Agent Characteristics of Java: DrawbacksAgent Characteristics of Java: Drawbacks

Inadequate Support for Resource Control Inadequate Support for Resource Control Denial of Service

Agent Will Loop and Waste Processor Cycles or Memory Resources

No Protection of ReferencesNo Protection of References Objects are Allowed Access to the Public

Methods of a Java Object A Proxy Provides Protection of References and

Location Transparency Object Inserted Between Caller and Callee

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Agent-1.48

DrawbacksDrawbacks

No Object Ownership of ReferencesNo Object Ownership of References An Agent’s Execution Thread May Be Deleted An Agent Object Can Not Be Voided

No Support for Preservation and Resumption of No Support for Preservation and Resumption of Execution StateExecution State Java Does Not Allow Retrieval of the Full

Execution State of an Object Agent Relies on Internal Attribute Values and

External Events to Direct its Behavior

CSE300

Agent-1.49

Aglet EnvironmentAglet Environment

IBM Aglets Workbench IBM Aglets Workbench Assists in Bringing Mobile Agents to Life Implemented in Java

IBM Aglets Workbench Operation IBM Aglets Workbench Operation Based on the Java Programming Language

System Aglets Framework

Provides the Mobile-agent-specific Components of the Workbench

Introduces the Notion of an Aglet A Mobile (Agile) Agent Written in Java and

Named After its Framework Base Class

CSE300

Agent-1.50

Aglet APIAglet API

Four Basic Elements Aglet Proxy Context Identifier

Aglet Mobile Agent that Moves Across the Network Responds to Messages Runs on its Own Thread of Execution

PProxy Shield that Protects the Aglet From Direct

Access to its Methods Can Have Remote Access to the Aglet (Hides

Aglet’s Real Location)

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Agent-1.51

Aglet API: ElementsAglet API: Elements

CContext Basically the Same As a Place Houses the Engines

Engines House the Aglets Addressed in the Same Manner As a Place

IIdentifier Element of the Aglet Each Aglet Has It’s Own Unique Identifier Required Entity Used for Recognition and

Locating Traveling Agents

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Agent-1.52

Relationship between Aglet and ProxyRelationship between Aglet and Proxy

InteractionClients Proxy Aglet

Proxy Represents the AgletProxy Represents the Aglet Shields Public Methods for Potential MisuseShields Public Methods for Potential Misuse Can Hide the “Actual” Location of AgletCan Hide the “Actual” Location of Aglet Proxy and Aglet on Different Computing NodesProxy and Aglet on Different Computing Nodes

CSE300

Agent-1.53

Relationship between Host, Server Relationship between Host, Server Process(Engine), and ContextsProcess(Engine), and Contexts

Context Context Context

Host

Server Process (Engine)

Network

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Agent-1.54

Aglet: OperationsAglet: Operations

Six Basic Operations Creation Cloning Dispatching Retraction Activation and Deactivation Disposal

Creation Initializes a New Aglet Assigns Aglet an Identifier

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Agent-1.55

Basic OperationsBasic Operations

CCloning Produce an Identical Copy of an Aglet (itself) Differences Between Clone and Original Aglet

Identifier Place of Execution

DDispatching Aglet is Transported (Pushed) From One

Context to Another Retraction

Concept that Returns an Aglet Back to its Original Context

Original Context Pulls Back the Aglet From the Current Context

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Agent-1.56

Basic OperationsBasic Operations

Deactivation and Activation Deactivation Must Occur Before Activation Deactivation Halts the Execution of an Aglet Activation Starts Execution of an Aglet Activation Must Occur to Restore the Aglet

DDisposal Stops Execution of an Aglet Removes an Aglet From its Current Context

Classification of Six Basic Aglet Operations Classified as the Life Cycle of an Aglet

Observation of Six Basic Aglet Operations Context Functions Just Like a Place

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Agent-1.57

Agent Life-Cycle ModelAgent Life-Cycle Model

Aglet Aglet

Class File

DiskStorage

Create Deactivate Activate

Dispose

Clone

Context A Context B

Retract

Dispatch

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Agent-1.58

Aglet MethodsAglet Methods

Aglet Programming Model Similar to the Java Event Model Event Based Listeners Used to Perform Event Actions

Three Event Model Listeners Clone Listener Mobility Listener Persistence Listener

ActionsActions Listen for the Event They are Named After Listeners Can Be Customized to Perform

Specific Actions When the Listener Event Occurs

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Agent-1.59

Relationship between Aglet and its Relationship between Aglet and its ListenersListeners

Aglet

Clone Events

Mobility Events

Persistence Events

CloneListener

MobilityListener

PersistenceListener

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Agent-1.60

Event Model ListenersEvent Model Listeners

Clone Listener Listens for Cloning Events Actions Can Be Customized to Occur Before,

During, or After the Cloning Mobility Listener

Listens for Mobility Events Actions Can Be Customized to Occur When an

Aglet is About to Be Dispatched, Retracted, or Arrives in a New Context

Persistence Listener Listens for Persistence Events Actions Can Be Customized to Occur When an

Aglet is About to Be Deactivated or Has Been Activated

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Agent-1.61

Aglet API: Classes and InterfacesAglet API: Classes and Interfaces

Aglet API Simple and Flexible Represents Lightweight Pragmatic Approach to

Mobile Agents Java Classes

Aglet Message Futurereply Agletid Agletproxy

Java Interfaces Agletproxy Agletcontext

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Agent-1.62

Aglet API: ClassesAglet API: Classes

Aglet Class Contains All Methods Needed to Perform the

Basic Aglet Operations Basis for Building All Aglets Contains All the Elements of the Aglet

Aglet Creation Create a Customized Aglet

import com.ibm.aglet.*;

public class MyFirstAglet extends Aglet{

//Put aglet’s methods here

}

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Agent-1.63

Aglet and Message ClassAglet and Message Class

Aglet Class Example: TThe Dispatch Method Dispatches an Aglet to a Remote Context The Method Call Contains the URL of the

Remote Contextdispatch(new URL(atp://remote.host.com/context”));

Message Class Communication of Aglets is Performed by

Exchanging Message Objects Agletproxy Class is Responsible for Actually

Sending and Receiving the Messages Message Creation

Field ‘Type’ Set When Message Created Second Field of Message Constructor is

Optional

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Agent-1.64

Message ClassMessage Class

CodeCodeMessage myName = new Message(“my name”, “Lois”);

orMessage yourName = new Message(“Steve”);

Message Class Example: TThe handleMessage Method Returns True if Message is Handled

public boolean handleMessage(Message msg){

if(msg.sameKind(“hello”)){

doHello(); //respond to ‘hello’ message

return true; //yes I handled message

}

else

return false; //not handled message

}

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Agent-1.65

AgletProxy and Future Reply ClassAgletProxy and Future Reply Class

Message Objects are Sent Using the Agletproxy Class Methods Object sendMessage(Message msg) FutureReply sendFutureMessage(Message msg) void sendOnewayMessage(Message msg)

Code Exampleproxy.sendMessage(myName);String name = (String)proxy.sendMessage(yourName);

FutureReply Class Evaluates Wether a Reply will Be Given to a

Message An Aglet Can Perform Another Task While

Waiting for the Reply

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Agent-1.66

Future Reply ClassFuture Reply Class

Future Reply Objects are Retrieved Using the Future Reply Objects are Retrieved Using the Agletproxy Class MethodAgletproxy Class Method sendFutureMessage(msg)

Code Example Sender of Message Can Perform Another Task

(doPeriodicWork()) While Waiting for Reply

FutureReply future = proxy.sendFutureMessage(msg);

while (!future.isAvailable()){

doPeriodicWork();

}

Object reply = future.getReply();

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Agent-1.67

AgletID ClassAgletID Class

AgletID Class Represents the Identifier of the Aglet The Identifier is Unique to Each Aglet The Identifier Object Hides the Implementation

Specific Representation of the Aglet Identity Code ExampleCode Example

Identifier can be Retrieved from the Aglet and its ProxyAgletID aid = proxy.getAgletID();

Query the Context to Retrieve Aglet with Identity aid (must have the Identifier aid and Context)proxy = context.getAgletProxy(aid);

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Agent-1.68

Aglet API: InterfacesAglet API: Interfaces

Agletproxy Interface The Handle of the Aglet Provides the Method of Communication

Between Aglets Aglet Handle Design Benefits

Used by Another Aglet that is Attempting to Communicate With that Aglet

Provides the Aglet With Protection From Non-authorized Access

Can Provide a Remote Location for the Aglet

CSE300

Agent-1.69

AgletProxy and AgletContextAgletProxy and AgletContext

Retrieval and Setting Methods of ProxiesRetrieval and Setting Methods of Proxies Aglet Can Get its Own Proxy

Aglet.getProxy(); Retrieve an Enumeration of Proxies

AgletContext.getAgletProxies(); Get an Aglet Proxy for a Given Identifier

text.getAgletProxy(); Place AgletProxy Object into Context Property

AgletContext.setProperty(); Aglet Context

Execution Environment for Aglets Provides Actual Entity of the Place Houses the Aglet Aglet is Created, Sleeps, & Dies in the Context

CSE300

Agent-1.70

AgletContextAgletContext

Agletcontext Interface An Aglet Will Live in the Context Get Information About Environment Send Messages to Environment Maintaining and Managing Running Aglets in

an Environment Where Host System is Secure Against Malicious Aglets

Agletcontext Interface Methods Aglet Class can Gain Access to Current Context

Context = Getagletcontext(); Aglet can Create New Aglets (Must Have

Access to Context)Context.Createaglet(…);

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Agent-1.71

AgletContextAgletContext

Retract (Pull) Remotely Located Aglets Into Current ContextContext.Retractaglet(remotecontexturl,

Agletid); Retrieve a List of Proxies of its Fellow Aglets

in the Same ContextProxies = Context.Getagletproxies();

There are Numerous Methods for the Interfaces Listed Above is an Ala Carte Example of What

the API Can Perform

CSE300

Agent-1.72

AgletContextAgletContext

Aglet Example: Remote File Update Premise: Large Multiple Remote Files that

Must be Updated by Word Replacement One Solution: Move Files to Central Server,

Perform Update, and Move Files Back Another Solution: An Aglet that Updates Files

by Replacing All Occurrences of One Specified Word in the Files With Another Specified Word

Distributes the Load of Updates to Multiple Servers

We’re Moving “Code” Rather Than Files

CSE300

Agent-1.73

Multiple Aglets Updating Files in ParallelMultiple Aglets Updating Files in Parallel

Aglet AgletAglet

Aglet

Host (Updating)

Host HostHostF FF FF F

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Agent-1.74

Update File AgletUpdate File Aglet

Import com.ibm.aglet.*;import com.ibm.aglet.event.*;import java.net.*;import java.io.*;public class UpdateFile extends Aglet{

URL destination = null;File dir = null;String from = null;String to = null;public void onCreation(Object args){

destination = (URL)((Object[])args)[0];

dir = (File)((Object[])args)[1];

from = (String)((Object[])args)[2];

to = (String)((Object[])args)[3];

addMobilityListener(){

new MobilityAdapter(){

CSE300

Agent-1.75

Update File AgletUpdate File Aglet

Public void onArrival(MobilityEvent e){

replace(args.file,args.from,args.to);

dispose(); }

}

}

try{

dispatch(args.destination);

}catch (Exception e){

System.out.println(“Failed to dispatch.”);

}}void replace(File, file, String, from, Sting

to){

//Open ‘file’ and replace ‘from’ with ‘to’}

CSE300

Agent-1.76

Distributed ComputingDistributed Computing

Role of Agents in Distributed ComputingRole of Agents in Distributed Computing Range From Smart Matter to Electronic Email

PPossible Areas in Distributed Computing Where Agents Would Be Useful Advertising Air-Traffic Control Business Process Re-engineering Command and Control Data Mining Digital Libraries Electronic Commerce Entertainment E-mail Filtering

CSE300

Agent-1.77

Role of Agents: Areas of InterestRole of Agents: Areas of Interest

Education Information Retrieval/Management News Retrieval Network Management Personal Digital Assistants (PDAS) Secure Brokering Smart Matter Smart Databases Scheduling/Diary Management Workflow Management Numerous Other Areas that are Being

Researched and Developed

CSE300

Agent-1.78

Role of Agents: AbilitiesRole of Agents: Abilities

Why Agents? Abilities are Productive for Increasing the

Quality of Distributed Computing Agent Abilities

Collect Data From Numerous Places Searching and Filtering Information Monitoring Target Information Dissemination Agent-to-Agent Negotiation Perform Parallel Computations Barter Enhance Telecommunication Network Services Controller for Smart Matter Enhance Entertainment

CSE300

Agent-1.79

Data Collection, Search, and MonitorData Collection, Search, and Monitor

Collect Data From Numerous Places An Agent on a Network Could Retrieve Data

From Numerous Computer Stations One Application that May Be Useful Would Be

a Software Registration Agent Searching and Filtering Information

Discards Useless Information Saves an Immense Amount of Time

Monitoring Monitor Certain Information Specified by User Retrieve Information Specified by User

Requests

CSE300

Agent-1.80

Real Time, Communication, Computation, Real Time, Communication, Computation, and Barteringand Bartering

Target Information Dissemination Real Time Information Being Retrieved

News, Stock Quotes, Advertisements, and Software Updates for Venders

Information Specified by User Negotiate Between One Another (Agent-to-agent)

Agents Communicate With Other Agents PPerform Parallel Computations

Agents Communicate With One Another Agents Share Information

BBarter Agents Assume the Place of the User Agent Negotiates the Deal

CSE300

Agent-1.81

Telecommunications, Controller, and Telecommunications, Controller, and EntertainmentEntertainment

Enhance Telecommunication Network Services Store Information of Services Provide User With Authorized Services

Controller for Smart Matter Monitor Equipment Inform User of State of Equipment

Enhance Entertainment Agent-to-Agent Communication Between

Players User Programmed Strategic Agent

The Information Above is Not Conclusive of All The Information Above is Not Conclusive of All the Different Abilities of Mobile Agents (Endless)the Different Abilities of Mobile Agents (Endless)

CSE300

Agent-1.82

Future Evolution of Intelligent Agent Future Evolution of Intelligent Agent EntitiesEntities

Software Registration AgentSoftware Registration Agent Search and Filter EnginesSearch and Filter Engines Monitor/Supply Info. on Real Time BasisMonitor/Supply Info. on Real Time Basis Real Time AdvertisementReal Time Advertisement User Filter for Unwanted InformationUser Filter for Unwanted Information Real Time Work Environment UpdateReal Time Work Environment Update Pleasure/business Travel AgentPleasure/business Travel Agent Parallel ProcessingParallel Processing Network Service AdministratorNetwork Service Administrator Monitor Physical Aspects of Embedded SystemsMonitor Physical Aspects of Embedded Systems Computer Gaming PawnComputer Gaming Pawn

CSE300

Agent-1.83

Possibilities of Intelligent Agent EntitiesPossibilities of Intelligent Agent Entities

List of Future Evolution of Intelligent Agent List of Future Evolution of Intelligent Agent Entities InconclusiveEntities Inconclusive With the Advancement of Technology and a

Need for a Faster Result, the Possibilities of Implementations of Mobile Agents are Vast

Software Registration Agent Retrieve Registration Numbers for Certain

Software Applications Data Would Be Used to Determine If a

Computer System Had Unique Software Applications

CSE300

Agent-1.84

Search, Filter, and MonitorSearch, Filter, and Monitor Search and Filter EnginesSearch and Filter Engines

Email Applications: A User Could Filter Mail Based on a Certain

Keyword and Not Receive Junk Mail Provide a More Extensive Search for a User Use Numerous Resources Return Specific Items for the User Search or Filter While the User is Performing

Another Activity

CSE300

Agent-1.85

Real Time PossibilitiesReal Time Possibilities

Monitor and Supply Information on Real Time Monitor and Supply Information on Real Time BasisBasis Provide News on a Real Time Basis Monitor News Based on Certain Information Retrieve the News that the User Requests Used for Stocks, Shopping (Checking If an

Item Goes on Sale), and Even Weather The Amount of Possibilities is Endless

Real Time AdvertisementReal Time Advertisement Advertisers Find a Way to Capitalize on Every

New Software Invention Available Companies May Send Advertisements Along With

the Information Being Received Like News

CSE300

Agent-1.86

Real Time PossibilitiesReal Time Possibilities

User Filter for Unwanted InformationUser Filter for Unwanted Information User May Want to Filter Out Certain

Information Being Received Agent Application Required to Filter Out

Unwanted Advertisements Real Time Work Environment UpdateReal Time Work Environment Update

Schedule a Meeting Each of the Employee’s Agents Would Work

Together to Schedule the Meeting for all Employees Update Team Members on New Developments

of a Project Each Agent Would Update the Other Agents and

Then Return the Information to the Worker

CSE300

Agent-1.87

Work and TravelWork and Travel

Pleasure/Business Travel AgentPleasure/Business Travel Agent User’s Own Personal Shopper, Broker, or

Travel Agent Electronic Commerce

Shop/Haggle for a User on Any Type of Goods Search Criteria Given by a User

Where to Go on Vacation and What Price for Airline Tickets

What Stocks to Buy or Sell User Tells Agent to Make a Deal or Not

Once Agent Retrieves All the Information. Agent Could then Finalize the Deal for the User

Vacation Reservations are made, or Merchandise is Purchased

CSE300

Agent-1.88

Network Services and MonitoringNetwork Services and Monitoring

Network Service AdministratorNetwork Service Administrator Agent Responsible for the User Configuration Agents Supplies the Host With User Privileges

to Services Could Be Used for Cable Systems or Network

Providers Monitor of Physical Aspects of Embedded SystemsMonitor of Physical Aspects of Embedded Systems

Monitor Temperature, Speed, or Other Physical Characteristics

Inform User of a Malfunction Assume the Position of Smart Matter Provide a More Efficient Way to Monitor

Physical Aspects of Embedded Systems

CSE300

Agent-1.89

Computer GamingComputer Gaming

Computer Gaming PawnComputer Gaming Pawn Perform All the Battling for the User User Could Program the Agent to Function

Accordingly Strategic Moves

Numerous Network Game Possibilities Gambling, Role Playing, and Strategy Games

Agent-to-Agent Communication Used to Provide Enhance Online Gaming Possibilities

CSE300

Agent-1.90

Conclusion and FutureConclusion and Future

ConclusionConclusion Agent Concepts Barely Five Years Agents Seem to be the Up and Coming

Technology of the Future The Possibilities and Capabilities of Agents are

Endless The Mobile Agent Alone Has Not Been Covered in

Research Extensively Aglets Have a Chance of Being the Building

Blocks of Front Running Technology As Long As Java Proves to Be a Secure Language

Standardization Issues Must be Addressed for Different Agent Systems to Interact!

CSE300

Agent-1.91

Conclusion and FutureConclusion and Future

Future UsesFuture Uses Everyday People are Finding New Uses for

Agents Provide Users With Assistance Provide Users With More Free Time Agents Most Likely, Will Become an Everyday

Occurrence in Applications Assist Users and Do Work on Their Behalf

are Agents the Future of Today’s and Tomorrow’s are Agents the Future of Today’s and Tomorrow’s Applications?Applications?

CSE300

Agent-1.92

Future ResearchFuture Research

Another Facet of Agents is the Intelligent AgentAnother Facet of Agents is the Intelligent Agent Mobile Agents are Used for Intelligent Agents Researchers are Trying to Implement an Agent

With Artificial Intelligence Current Developing ApplicationsCurrent Developing Applications

IBM is Developing a Memory Agent Application Used to Detect Breast Cancer

IBM Claims the Agent Learns Based on Previous Input

Uses a Learning Algorithm to Predict the Numbers for Detection

CSE300

Agent-1.93

IBM Research ProductsIBM Research Products

Other IBM Products Using the Memory Agent Memoryagent Knowledge Capture

Learns What People Know Builds a Knowledge Base Incrementally Operates While People Do Their Normal Jobs

Memoryagent Virtual Consultation Allows People to Consult the Knowledge of Others Eliminates Need for Speaking to Them in Person

CSE300

Agent-1.94

ReferencesReferences

[1]: Danny B. Lange and Mitsuru Oshima, “Programming and Deploying Java [1]: Danny B. Lange and Mitsuru Oshima, “Programming and Deploying Java Mobile Agents with Aglets”, Addison Wesley Longman, Reading MA, 1998.Mobile Agents with Aglets”, Addison Wesley Longman, Reading MA, 1998.

[2]: [2]: http://www.http://www.javaworldjavaworld.com/.com/javaworldjavaworld//jwjw-04-1997/-04-1997/jwjw-04-agents.html-04-agents.html

[3]: [3]: http://www.http://www.mscimsci..memphismemphis..eduedu/~/~franklinfranklin//AgentProgAgentProg.html.html

[4]: [4]: http://www.http://www.javaworldjavaworld.com/.com/javaworldjavaworld//jwjw-04-1997/-04-1997/jwjw-04-hood.html-04-hood.html

[5]: [5]: http://www.http://www.trltrl..ibmibm.co..co.jpjp//agletsaglets/JAAPI-/JAAPI-whitepaperwhitepaper.html.html

[6]: [6]: http://http://luckyspcluckyspc..lborolboro.ac..ac.ukuk/Docs/Papers/Mesela97.html/Docs/Papers/Mesela97.html

[7]: [7]: http://www.http://www.javaworldjavaworld.com/.com/javaworldjavaworld//jwjw-05-1997/-05-1997/jwjw-05-hood.html-05-hood.html

[8]: [8]: http://www.http://www.trltrl..ibmibm.co..co.jpjp//agletsaglets//whitepaperwhitepaper..htmhtm

[9]: [9]: http://www.networking.http://www.networking.ibmibm.com/.com/iagiag//iaghomeiaghome.html#new.html#new