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Solve real problems with aglets, a type of mobile agent

Part 2 of this series explains the significance of mobile agents, such as aglets -- IBM Japan's Java-based, autonomous software agent technology

By Bill Venners, JavaWorld.com, 05/01/97

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Page 2 of 5

Searching and filtering
Given the ever increasing amount of information available on the Internet and other networks, the activity of collecting information from a network often amounts to searching through vast amounts of data for a few relevant pieces of information. Filtering out the irrelevant information can be a very time-consuming and frustrating process. On behalf of a user, a mobile agent could visit many sites, search through the information available at each site, and build an index of links to pieces of information that match a search criterion.

Searching and filtering exhibits an attribute common to many potential applications of mobile agents: knowledge of user preferences. Although mobile agents do not have to be "representative" or "intelligent," they often are. Here, an agent is given knowledge of user preferences in terms of a search criterion and an itinerary, and sent out into the network on the user's behalf. It sifts through huge amounts of data for those pieces of information of particular interest to the user. At some point, it returns to the user to report its findings.

Monitoring
Sometimes information is not spread out across space (on the disks of many different computers hooked to the same network), but across time. New information constantly is being produced and published on the network. Agents can be sent out to wait for certain kinds of information to become available.

For example, an agent could go to a stock market host, wait for a certain stock to hit a certain price, then buy some of it on behalf of its user. Another example is personalized news gathering. An agent could monitor various sources of news for particular kinds of information of interest to its user, then report back when relevant information becomes available.

This kind of application highlights the asynchronous nature of mobile agents. If you send out an agent, you needn't sit and wait for the results of its information gathering. You can program an agent to wait as long as it takes for certain information to become available. Also, you needn't stay connected to the network until an agent returns. An agent can wait until you reconnect to the network before making its report to you.

Targeted information dissemination
Another potential use of mobile agents is to distribute interactive news or advertising to interested parties. Unfortunately, this means mobile agents, like e-mail, can be used for spam -- indiscriminate distribution of information, usually advertising. (There will likely be a market for agents that filter the spam out of incoming mobile agents.)

Negotiating
Besides searching databases and files, agents can gain information by interacting with other agents. If, for example, you want to schedule a meeting with several other people, you could send a mobile agent to interact with the representative agents of each of the people you want to invite to your meeting. The agents could negotiate and establish a meeting time.

In this case, each agent contains information about its user's schedule. To agree upon a meeting time, the agents exchange information.

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Resources
  • Previous Under The Hood articles:
  • The lean, mean virtual machine -- Gives an introduction to the Java virtual machine.
  • The Java class file lifestyle -- Gives an overview to the Java class file, the file format into which all Java programs are compiled.
  • Java's garbage-collected heap -- Gives an overview of garbage collection in general and the garbage-collected heap of the Java virtual machine in particular.
  • Bytecode basics -- Introduces the bytecodes of the Java virtual machine, and discusses primitive types, conversion operations, and stack operations in particular.
  • Floating Point Arithmetic -- Describes the Java virtual machine's floating-point support and the bytecodes that perform floating point operations.
  • Logic and Arithmetic -- Describes the Java virtual machine's support for logical and integer arithmetic, and the related bytecodes.
  • Objects and Arrays -- Describes how the Java virtual machine deals with objects and arrays, and discusses the relevant bytecodes.
  • Exceptions -- Describes how the Java virtual machine deals with exceptions, and discusses the relevant bytecodes.
  • Try-Finally -- Describes how the Java virtual machine implements try-finally clauses, and discusses the relevant bytecodes.
  • Control Flow -- Describes how the Java virtual machine implements control flow and discusses the relevant bytecodes.
  • The Architecture of Aglets-- Describes the inner workings of Aglets, IBM's autonomous Java-based software agent technology.