Research And Application Of A Moving Subject

As Internet information resources grow in size, along with the number of people accessing them, it is often most efficient to process quires and updates at the site where the data is located. This processing can be accomplished by using a traditional Client/Server network interface, which constraints the client to the set of queries supported by the server, or requires the server to send all data to the client for processing. The former is inflexible; the latter is inefficient. A new concept is the so-called mobile agent, which means sending agents to remote information sites. In there, mobile agents retrieve and update data with high performance by advantage of locality between them.A mobile agent is an autonomous program that can migrate under its own control from machine to machine in a heterogeneous network. A mobile agent can suspend its execution at an arbitrary point, transport itself to another machine, and then resume execution from the point of suspension. A mobile agent is self-contained and knows what to do and where to go. A mobile agent can use specialized or unique algorithms or processing techniques to specialize the server function on behalf of its owner, while the information server only needs to provide basic operation primitives.Two kinds of agent mobility theories and a mobile agent distributed computing model (MADCM) are presented.The ability and knowledge of a cooperative agent are described by resources, which are agent addresses, languages, interpreters, codes and files, so the mobile state of a cooperative agent is defined as its resource state. The internal and external description of the cooperative agent resource state can be used to capture, transfer, and restore a transported cooperative agent.The mobile state of an autonomous task agent is defined as its thread execution state. An application-level simulation model of the thread migration is presented, which gets rid of inefficiency and difficult acceptance of the traditional process or thread migration due to the capture of the run time stack and the modification of the run time kernel.The presented mobile agent distributed computing model (MADCM)...