南京大学：移动Agent系统支撑（PPT讲稿）Agent Mobility Software Agent

Agent Mobility Software Agent 余萍 yuping@anjU.edu.cn

Agent Mobility 余萍 yuping@nju.edu.cn

Agent: weak notions Wooldridge and jennings An Agent is a piece of hardware or(more commonly) software-based computer system that enjoys the following properties Autonomy: agents operate without the direct intervention of humans or others, and have some kind of control over their actions and internal state Pro-activeness: agents do not simply act in response to their environment they are able to exhibit goal-directed behavior by taking the initiative Reactivity: agents perceive their environment and respond to it in timely fashion to changes that occur in it Social Ability: agents interact with other agents(and possibly humans)via some kind of agent-communication language 2021/2/2 Institute of Computer Software, Nanjing University

 Wooldridge and Jennings ▪ An Agent is a piece of hardware or (more commonly) software-based computer system that enjoys the following properties ▪ Autonomy: agents operate without the direct intervention of humans or others, and have some kind of control over their actions and internal state; ▪ Pro-activeness: agents do not simply act in response to their environment, they are able to exhibit goal-directed behavior by taking the initiative. ▪ Reactivity: agents perceive their environment and respond to it in timely fashion to changes that occur in it. ▪ Social Ability: agents interact with other agents (and possibly humans) via some kind of agent-communication language.” 2021/2/2 Institute of Computer Software, Nanjing University 2 2

Agent: strong notions Wooldridge and jennings Weak notion in addition to Mobility: the ability of an agent to move around a network Veracity: agent will not knowingly communicate false information Benevolence: agents do not have conflicting goals and always try to do what is asked of it Rationality: an agent will act in order to achieve its goals and will not act in such a way as to prevent its goals being achieved 2021/2/2 Institute of Computer Software, Nanjing University

 Wooldridge and Jennings ▪ Weak notion in addition to ▪ Mobility: the ability of an agent to move around a network ▪ Veracity: agent will not knowingly communicate false information ▪ Benevolence: agents do not have conflicting goals and always try to do what is asked of it. ▪ Rationality: an agent will act in order to achieve its goals and will not act in such a way as to prevent its goals being achieved 3 2021/2/2 Institute of Computer Software, Nanjing University 3

Outline Code mobility Mobile agent Migration Mechanism in Mobile Agent System 2021/2/2 Institute of Computer Software, Nanjing University

 Code Mobility  Mobile Agent  Migration Mechanism in Mobile Agent System 2021/2/2 Institute of Computer Software, Nanjing University 4

代码迁移技术( Code Mobility) What is code mobility? Code mobility is the capability to dynamically change the bindings between code fragments and the location where they are executed Involves a Change in bindings dynamically b Relocation of code Network nodea Node b 2021/2/2 Institute of Computer Software, Nanjing University

 What is code mobility? ▪ Code mobility is the capability to dynamically change the bindings between code fragments and the location where they are executed. ▪ Involves: a. Change in bindings dynamically b. Relocation of code Network Node A Node B 2021/2/2 Institute of Computer Software, Nanjing University 5

Why Code Mobility Limitations and drawbacks with traditional approaches in large-scale distributed settings like the internet a. scalability (growing size of network, network partitions) b. Customizability (tailor functionality to specific needs) C. Flexibility (dynamic nature of comm. infrastructure) d. Extensibility (to add new features) 2021/2/2 Institute of Computer Software, Nanjing University

 Limitations and drawbacks with traditional approaches in large-scale distributed settings like the Internet a. Scalability (growing size of network, network partitions) b. Customizability (tailor functionality to specific needs) c. Flexibility (dynamic nature of comm. infrastructure) d. Extensibility (to add new features) 2021/2/2 Institute of Computer Software, Nanjing University 6

Advent of Mobile Code Systems(MCS) Idea taken from process migration techniques used in distributed operating systems like a, locus b. emerald C COoL( Chorus) 2021/2/2 Institute of Computer Software, Nanjing University

 Idea taken from process migration techniques used in distributed operating systems like: a. Locus b. Emerald c. COOL (Chorus) 2021/2/2 Institute of Computer Software, Nanjing University 7

Innovations of mcss Code mobility is exploited on Internet-scale Programming is location aware Mobility is under programmer s control Mobility is not performed just for load balancing service customization extensibility autonomy> fault-tolerance support for disconnected operations 2021/2/2 Institute of Computer Software, Nanjing University 8

 Code mobility is exploited on Internet-scale  Programming is location aware  Mobility is under programmer’s control  Mobility is not performed just for load balancing - service customization - extensibility - autonomy → fault-tolerance - support for disconnected operations 2021/2/2 Institute of Computer Software, Nanjing University 8

Benefits of mobile code Service customization Supports last phase of software development Deployment and maintenance(in distributed systems-to upgrade or add a new feature) Autonomy of application components Fault-tolerance Data management flexibility and protocol encapsulation 2021/2/2 Institute of Computer Software, Nanjing University

 Service Customization  Supports last phase of software development → Deployment and maintenance (in distributed systems – to upgrade or add a new feature)  Autonomy of application components  Fault-tolerance  Data management flexibility and protocol encapsulation 2021/2/2 Institute of Computer Software, Nanjing University 9

Mobile Code applications Distributed Information Retrieval Active documents Advanced Telecommunication Services (video conferencing, video on demand) Remote Device Control and Configuration Workflow management and Cooperation Active networks E-Commerce 2021/2/2 Institute of Computer Software, Nanjing University

 Distributed Information Retrieval  Active Documents  Advanced Telecommunication Services (video conferencing, video on demand)  Remote Device Control and Configuration  Workflow management and Cooperation  Active networks  E-Commerce 2021/2/2 Institute of Computer Software, Nanjing University 10