Fault Tolerance Approach in Mobile Agents for Information Retrieval Applications Using Check Points

Mobile agents have emerged as major programming paradigm for distributed applications. Mobile agents are the intelligent programs that act autonomously on behalf of a user and can migrate from one host to another host in a network in order to satisfy the requests made by their clients. A prerequisite for their use, however, is that they should be executed reliably independent of failures. Improving the survivability of mobile agents in presence of agent server failures is an important issue in order to guarantee continuous execution of mobile agents. Thus it is very important to make mobile agents fault tolerant. In this paper, we propose fault tolerance mechanism for the scenarios where the agent stops its execution due to fault on any server in the itinerary. Our approach makes use of check pointing, partial results or data retrieved and the address of last host visited is saved prior before the agent visits the next host in the itinerary .The proposed mechanism has been implemented on the Aglets mobile agent system and evaluated in terms of parameters such as round trip time, Reliable migration time, Check point time. The results show the improvement in reliability and performance, especially for mobile agents in Internet application.