A Survey of Checkpointing Algorithms in Mobile Ad Hoc Network

Checkpoint is defined as a fault tolerant technique that is a designated place in a program at which normal processing is interrupted specifically to preserve the status information necessary to allow resumption of processing at a later time. If there is a failure, computation may be restarted from the current checkpoint instead of repeating the computation from beginning. Checkpoint based rollback recovery is one of the widely used technique used in various areas like scientific computing, database, telecommunication and critical applications in distributed and mobile ad hoc network. The mobile ad hoc network architecture is one consisting of a set of self configure mobile hosts capable of communicating with each other without the assistance of base stations. The main problems of this environment are insufficient power and limited storage capacity, so the checkpointing is major challenge in mobile ad hoc network. This paper presents the review of the algorithms, which have been reported for checkpointing approaches in mobile ad hoc network

Rollback recovery with low overhead for fault tolerance in mobile ad hoc networks

AbstractMobile ad hoc networks (MANETs) have significantly enhanced the wireless networks by eliminating the need for any fixed infrastructure. Hence, these are increasingly being used for expanding the computing capacity of existing networks or for implementation of autonomous mobile computing Grids. However, the fragile nature of MANETs makes the constituent nodes susceptible to failures and the computing potential of these networks can be utilized only if they are fault tolerant. The technique of checkpointing based rollback recovery has been used effectively for fault tolerance in static and cellular mobile systems; yet, the implementation of existing protocols for MANETs is not straightforward. The paper presents a novel rollback recovery protocol for handling the failures of mobile nodes in a MANET using checkpointing and sender based message logging. The proposed protocol utilizes the routing protocol existing in the network for implementing a low overhead recovery mechanism. The presented recovery procedure at a node is completely domino-free and asynchronous. The protocol is resilient to the dynamic characteristics of the MANET; allowing a distributed application to be executed independently without access to any wired Grid or cellular network access points. We also present an algorithm to record a consistent global snapshot of the MANET

Trust Based Node Recovery and Checkpointing Techniques in Manets

Checkpointing is a process of determining the vulnerability of node in case of any attack occurs in the network. It depends on the cluster change count value of the node. If the measure of the hop exchanges required to reach the destination node from the current node, is above the previously specified value, the node under consideration is unsafe and safe points must be implemented in between the path and different subnetworks within that network must have their own implemented safe points. The message must commits to the safe points as it reaches the respective sub networks. The message in the networks evolve over the certain subnetworks. The each subnetwork has the checkpoint node, that serves the purpose for communication between different subnetworks, or between the hops in different subnetworks. This phenomenon supports the system efficiency and preserves the robustness. The process retrieval methods, therefore, should be implemented with the use of the safe points to prevent system degradation. In this research paper, an efficient recovery protocol is designed for distributed transactions in MANETs so that failures can be minimised. Dynamic analysis has also been done and it is compared with other existing protocols to validate the attained result

Transparently Mixing Undo Logs and Software Reversibility for State Recovery in Optimistic PDES

The rollback operation is a fundamental building block to support the correct execution of a speculative Time Warp-based Parallel Discrete Event Simulation. In the literature, several solutions to reduce the execution cost of this operation have been proposed, either based on the creation of a checkpoint of previous simulation state images, or on the execution of negative copies of simulation events which are able to undo the updates on the state. In this paper, we explore the practical design and implementation of a state recoverability technique which allows to restore a previous simulation state either relying on checkpointing or on the reverse execution of the state updates occurred while processing events in forward mode. Differently from other proposals, we address the issue of executing backward updates in a fully-transparent and event granularity-independent way, by relying on static software instrumentation (targeting the x86 architecture and Linux systems) to generate at runtime reverse update code blocks (not to be confused with reverse events, proper of the reverse computing approach). These are able to undo the effects of a forward execution while minimizing the cost of the undo operation. We also present experimental results related to our implementation, which is released as free software and fully integrated into the open source ROOT-Sim (ROme OpTimistic Simulator) package. The experimental data support the viability and effectiveness of our proposal

Benchmarking Memory Management Capabilities within ROOT-Sim

In parallel discrete event simulation techniques, the simulation model is partitioned into objects, concurrently executing events on different CPUs and/or multiple CPUCores. In such a context, run-time supports for logical time synchronization across the different simulation objects play a central role in determining the effectiveness of the specific parallel simulation environment. In this paper we present an experimental evaluation of the memory management capabilities offered by the ROme OpTimistic Simulator (ROOT-Sim). This is an open source parallel simulation environment transparently supporting optimistic synchronization via recoverability (based on incremental log/restore techniques) of any type of memory operation affecting the state of simulation objects, i.e., memory allocation, deallocation and update operations. The experimental study is based on a synthetic benchmark which mimics different read/write patterns inside the dynamic memory map associated with the state of simulation objects. This allows sensibility analysis of time and space effects due to the memory management subsystem while varying the type and the locality of the accesses associated with event processin

Proxy Module for System on Mobile Devices (SyD) Middleware

Nowadays, users of mobile devices are growing. The users expect that they could communicate constantly using their mobile devices while they are also constantly moving. Therefore, there is a need to provide disconnection tolerance of transactions in the mobile devices’ platforms and its synchronization management. System on Mobile Devices (SyD) is taken as one of the examples of mobile devices’ platforms. The thesis studies the existing SyD architecture, from its framework into its kernel, and introduces the proxy module enhancement in SyD to handle disconnection tolerance, including its synchronization. SyD kernel has been extended for the purpose of enabling proxy module. SyDSync has been constructed for synchronization with the proxy. The timeout has been studied for seamless proxy invocation. A Camera application that tries to catch a stolen vehicle has been simulated for the practical purpose of using the proxy module extension