In
computer science, a mobile agent is a composition of
computer software and data that is able to migrate (move) from one
computer to another autonomously and continue its execution on the destination computer. In reality, the mobile agent is the code/object on the move which travels in its itinerary within the network of connected nodes.
Definition and overview
A ''mobile agent'' is a type of
software agent
In computer science, a software agent or software AI is a computer program that acts for a user or other program in a relationship of agency, which derives from the Latin ''agere'' (to do): an agreement to act on one's behalf. Such "action on behal ...
, with the feature of ''autonomy'', ''social ability'', ''learning'', and most significantly, ''mobility''.
More specifically, a mobile agent is a
process
A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic.
Things called a process include:
Business and management
* Business process, activities that produce a specific s ...
that can transport its state from one environment to another, with its data intact, and be capable of performing appropriately in the new environment. Mobile agents decide when and where to move. Movement is often evolved from
RPC methods. Just as a user directs an Internet browser to "visit" a website (the browser merely downloads a copy of the site, or one version of it in the case of dynamic web sites), a mobile agent accomplishes a move through data duplication. When a mobile agent decides to move, it
saves its own state (
process image
In computing, a system image is a serialized copy of the entire state of a computer system stored in some non-volatile form such as a file. A system is said to be capable of using system images if it can be shut down and later restored to exactly ...
), transports this saved state to the new host and resumes execution from the saved state.
A mobile agent is a specific form of
mobile code
In distributed computing, code mobility is the ability for running programs, code or objects to be migrated (or moved) from one machine or application to another. This is the process of moving mobile code across the nodes of a network as oppose ...
, within the field of
code mobility. However, in contrast to the
remote evaluation
In computer science, remote evaluation is a general term for any technology that involves the transmission of executable software code from a client computer to a server computer for subsequent execution at the server. After the code has finished ...
and
code on demand programming paradigms, mobile agents are active in that they can ''choose'' to migrate between computers at any time during their execution. This makes them a powerful tool for implementing
distributed applications in a
computer network.
There are two types of mobile agents. The classification is based on their migration path.
# Mobile agents with predefined path: these have a static migration path.
# Free roaming mobile agent:
these have a dynamic migration path. Depending on the present network condition, the mobile agent chooses its path.
An open multi-agent system (MAS) is a system in which agents, that are owned by a variety of stakeholders, continuously enter and leave the system.
History and Evolution
In the early 1990s,
General Magic
General Magic was an American software and electronics company co-founded by Bill Atkinson, Andy Hertzfeld, and Marc Porat. Based in Mountain View, California, the company developed precursors to "USB, software modems, small touchscreens, to ...
created the
Telescript language and environment for writing and executing mobile agents, and described it with the now-popular "
cloud" metaphor; as described by
Andy Hertzfeld
Andrew Jay Hertzfeld (born April 6, 1953) is an American software engineer and innovator who was a member of the original Apple Macintosh development team during the 1980s. After buying an Apple II in January 1978, he went to work for Appl ...
:
The company was unsuccessful, however.
Advantages
Some advantages which mobile agents have over conventional agents are:
* Computation bundles - converts computational client/server round trips to relocatable data bundles, reducing network load.
* Parallel processing -asynchronous execution on multiple
heterogeneous
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, size ...
network hosts
* Dynamic adaptation - actions are dependent on the state of the host environment
* Tolerant to network faults - able to operate without an active connection between client and server
* Flexible maintenance - to change an agent's actions, only the source (rather than the computation hosts) must be updated
*Bandwidth conversion which is conversion the bandwidth one host to another host.
*Reduces compilation time.
One particular advantage for remote deployment of software includes increased portability thereby making system requirements less influential.
See also
*
Code mobility
*
Java Aglets
*
JADE
Jade is a mineral used as jewellery or for ornaments. It is typically green, although may be yellow or white. Jade can refer to either of two different silicate minerals: nephrite (a silicate of calcium and magnesium in the amphibole group of ...
*
Fraglets
References
External links
Seven Good Reasons for Mobile AgentsMobile Agent Technologies
developer of AgentOS agent-based operating system. The inventor of Automatic Thread Migration (ATM).
hosts a center for investigating the security of mobile agents.
AgentLink IIIMobile-C
a multi-agent platform for mobile C/C++ agents.
JADE
an OSS mobile agent framework written in JAVA.
The Foundation for Intelligent Physical Agents
a standards body that defines an interface for agent-based interactions.
a project to develop a secure mobile agent server (last release 2007).
AgentLink III
{{Authority control
Distributed computing architecture
fr:Agent mobile