26-05-2012, 01:31 PM
MOBILE AGENTS TECHNOLOGY AND MOBILITY
[attachment=23151]
INTRODUCTION
As the Internet constantly expands, the amount of available
on-line information expands correspondingly. The issue of
how to efficiently find, gather and retrieve this information
has led to the research and development of systems and tools
that attempt to provide a solution to this problem. These
systems and tools are based on the use of MAs’ technology.
Mobile agents are processes (e.g. executing programs) that
can migrate from one machine of a system to another
machine (usually in the same system) in order to satisfy
requests made by their clients [1]. Mainly, a mobile agent
executes on a machine that hopefully provides the resource or
service that it needs to perform its job. If the machine does
not contain the needed resource/service, or if the mobile
agent requires a different resource/service on another
machine, the state information of the mobile agent is saved in
pre-defined manner, then transfer to a machine containing the
necessary resource/service is initiated, and the mobile agent
resumes execution at the new machine. Advantages of using
MAs include low network bandwidth since they only move
when they need to continue execution even when
disconnected from the network (typically for disconnected
mode), ability to clone itself to perform parallel execution,
easy implementation, deployment, and reliability.
MOBILE AGENT CHARACTERISTICS
A number of characteristics have been identified by [25,
22]. MAs should be autonomous, having the ability to act
without direct external interferences. In other words, they
have some degree of control over their data and states. MAs
should be Interactive in communicating with the environment
and other agents. MAs should be adaptive. In other words,
they have ability to respond to other agents or their
environment.
Mobility is the core property in a mobile agent concept
whereby the agent has the ability to migrate or transport itself
from one node to another within the same environment or
from node to another node in a different environment
autonomously. Proxy, MAs may act on behalf of someone or
for the benefit of some entities (e.g. software systems). In
order to act on behalf of others, mobile agents must have at
least a minimal degree of autonomy.
MOBILE AGENT REQUIREMENTS
This section addresses software requirements. There are
three main requirements: the mobile agent programme (code)
itself, mobile agent platforms (execution environment) and
mobile interfaces or mobile agent creators. Currently, the
traditional programming languages are facing real challenges
in implementing the new way of coding (e.g. mobility task)
but there are some conventional programming languages
which have the potential to be used for this purpose (e.g. Java
[4, 17]. Developers can build powerful distributed
applications by using Java due to its independence platform
feature.
In addition, mobility tasks can be implemented in Java via
Serialisation Interface whereby a mobile agent can be
serialised throughout a communication channel and
deserialised at the other end. However, when developing and
implementing the mobile agent code by using any capable
language (e.g. Java).
CURRENT DEVELOPMENTS AND APPLICATIONS
The major problem at present in the mobile agent arena is
the lack of development and implementation of the mobile
agent applications. Many mobile agent platforms have been
developed but there are only very few successful mobile
agent applications. There are obstacles standing against any
real development or improvement in the mobile agent as can
be seen in the next section. However, some real attempts (if
not true applications) have begun to appear around us.
Mobile agent technology has been employed in many areas
from network management tasks to information management.
CONCLUSION
Mobile agent technology can offer a new paradigm for
communication over heterogonous network channels. A
number of advantages of using mobile agent computing
paradigms have been proposed and identified. These
advantages include: overcoming network latency, reducing
network load, executing asynchronously and autonomously,
adapting dynamically, operating in heterogeneous
environments, and having robust and fault-tolerant behaviour.
However, the security and standardising issues still represent
a significant obstacle. The main conclusion which can be
drawn from our findings and investigation is that mobile
agent technology has the potential in increasing the
performance of networks as well as for software adopting
MAs.
[attachment=23151]
INTRODUCTION
As the Internet constantly expands, the amount of available
on-line information expands correspondingly. The issue of
how to efficiently find, gather and retrieve this information
has led to the research and development of systems and tools
that attempt to provide a solution to this problem. These
systems and tools are based on the use of MAs’ technology.
Mobile agents are processes (e.g. executing programs) that
can migrate from one machine of a system to another
machine (usually in the same system) in order to satisfy
requests made by their clients [1]. Mainly, a mobile agent
executes on a machine that hopefully provides the resource or
service that it needs to perform its job. If the machine does
not contain the needed resource/service, or if the mobile
agent requires a different resource/service on another
machine, the state information of the mobile agent is saved in
pre-defined manner, then transfer to a machine containing the
necessary resource/service is initiated, and the mobile agent
resumes execution at the new machine. Advantages of using
MAs include low network bandwidth since they only move
when they need to continue execution even when
disconnected from the network (typically for disconnected
mode), ability to clone itself to perform parallel execution,
easy implementation, deployment, and reliability.
MOBILE AGENT CHARACTERISTICS
A number of characteristics have been identified by [25,
22]. MAs should be autonomous, having the ability to act
without direct external interferences. In other words, they
have some degree of control over their data and states. MAs
should be Interactive in communicating with the environment
and other agents. MAs should be adaptive. In other words,
they have ability to respond to other agents or their
environment.
Mobility is the core property in a mobile agent concept
whereby the agent has the ability to migrate or transport itself
from one node to another within the same environment or
from node to another node in a different environment
autonomously. Proxy, MAs may act on behalf of someone or
for the benefit of some entities (e.g. software systems). In
order to act on behalf of others, mobile agents must have at
least a minimal degree of autonomy.
MOBILE AGENT REQUIREMENTS
This section addresses software requirements. There are
three main requirements: the mobile agent programme (code)
itself, mobile agent platforms (execution environment) and
mobile interfaces or mobile agent creators. Currently, the
traditional programming languages are facing real challenges
in implementing the new way of coding (e.g. mobility task)
but there are some conventional programming languages
which have the potential to be used for this purpose (e.g. Java
[4, 17]. Developers can build powerful distributed
applications by using Java due to its independence platform
feature.
In addition, mobility tasks can be implemented in Java via
Serialisation Interface whereby a mobile agent can be
serialised throughout a communication channel and
deserialised at the other end. However, when developing and
implementing the mobile agent code by using any capable
language (e.g. Java).
CURRENT DEVELOPMENTS AND APPLICATIONS
The major problem at present in the mobile agent arena is
the lack of development and implementation of the mobile
agent applications. Many mobile agent platforms have been
developed but there are only very few successful mobile
agent applications. There are obstacles standing against any
real development or improvement in the mobile agent as can
be seen in the next section. However, some real attempts (if
not true applications) have begun to appear around us.
Mobile agent technology has been employed in many areas
from network management tasks to information management.
CONCLUSION
Mobile agent technology can offer a new paradigm for
communication over heterogonous network channels. A
number of advantages of using mobile agent computing
paradigms have been proposed and identified. These
advantages include: overcoming network latency, reducing
network load, executing asynchronously and autonomously,
adapting dynamically, operating in heterogeneous
environments, and having robust and fault-tolerant behaviour.
However, the security and standardising issues still represent
a significant obstacle. The main conclusion which can be
drawn from our findings and investigation is that mobile
agent technology has the potential in increasing the
performance of networks as well as for software adopting
MAs.