Gathering over Meeting Nodes in Infinite Grid

The gathering over meeting nodes problem asks the robots to gather at one of the pre-defined meeting nodes. The robots are deployed on the nodes of an anonymous two-dimensional infinite grid which has a subset of nodes marked as meeting nodes. Robots are identical, autonomous, anonymous and oblivious. They operate under an asynchronous scheduler. They do not have any agreement on a global coordinate system. All the initial configurations for which the problem is deterministically unsolvable have been characterized. A deterministic distributed algorithm has been proposed to solve the problem for the remaining configurations. The efficiency of the proposed algorithm is studied in terms of the number of moves required for gathering. A lower bound concerning the total number of moves required to solve the gathering problem has been derived

Self-Stabilizing Checkpointing Algorithm in Ring Topology

If the variables used for the checkpointing algorithm have data faults, the algorithm may fail. In this paper, a selfstabilizing checkpointing algorithm is proposed for handling data faults in a ring network. The proposed algorithm can deal with concurrent initiation of checkpointing and at most one data fault per process. However, several processes may be faulty

Checkpointing and Recovery Algorithms Using Mobile Agents on a Hamiltonian Topology

Traditional message passing based checkpointing and rollback recovery algorithms perform well for closely coupled systems. In wide area distributed systems these algorithms may incur large overhead due to message passing delay and network traffic. So to design checkpointing and rollback recovery algorithms for wide area distributed systems, mobile agents are introduced. Network topology is assumed to be an arbitrary hamiltonian graph. Processes are mobile agent enabled. When a process wants to take a checkpoint or is restored after fault, it just creates two mobile agents. The rest of the work of creating a consistent global state (CGS) for checkpointing or finding a CGS in case of recovery, is performed by the mobile agents. In the worst case, for ¢ concurrent initiations among £ processes, checkpointing algorithm takes O(nk) mobile agent movements. A mobile agent carries O(1) size data irrespective of the number of processes

www.elsevier.com/locate/jpdc Self-stabilizing algorithm for checkpointing in a distributed system

If the variables used for a checkpointing algorithm have data faults, the existing checkpointing and recovery algorithms may fail. In this paper, self-stabilizing data fault detecting and correcting, checkpointing, and recovery algorithms are proposed in a ring topology. The proposed data fault detection and correction algorithms can handle data faults; at most one per process, but in any number of processes. The proposed checkpointing algorithm can deal with concurrent multiple initiations of checkpointing and data faults. A process can recover from a fault, using the proposed recovery algorithm in spite of multiple data faults present in the system. All the proposed algorithms converge in O(n) steps, where n is the number of processes. The algorithm can be extended to work for general topologies too