THE PERFORMANCE OF SOFT CHEKPOINTING APPROACH IN MOBILE COMPUTING SYSTEMS

Mobile computing raises many new issues such as lack of stable storage, low bandwidth of wireless channel, high mobility, and limited battery life. These new issues make traditional checkpointing algorithms unsuitable. Coordinated checkpointing is an attractive approach for transparently adding fault tolerance to distributed applications since it avoids domino effects and minimizes the stable storage requirement. However, it suffers from high overhead associated with the checkpointing process in mobile computing systems. In literature mostly, two approaches have been used to reduce the overhead: First is to minimize the number of synchronization messages and the number of checkpoints; the other is to make the checkpointing process nonblocking. Since MHs are prone to failure, so they have to transfer a large amount of checkpoint data and control information to its local MSS which increases bandwidth overhead. In this paper, we introduce the concept of 201C;Soft checkpoint201D; which is neither a tentative checkpoint nor a permanent checkpoint, to design efficient checkpointing algorithms for mobile computing systems. Soft checkpoints can be saved anywhere, e.g., the main memory or local disk of MHs. Before disconnecting from the MSS, these soft checkpoints are converted to hard checkpoints and are sent to MSSs stable storage. In this way, taking a soft checkpoint avoids the overhead of transferring large amounts of data to the stable storage at MSSs over the wireless network. We have also shown that our soft checkpointing scheme also adapts its behaviour to the characteristics of network

An Efficient Synchronous Checkpointing Protocol for Mobile Distributed Systems

Recent years have witnessed rapid development of mobile communications and become part of everyday life for most people. In order to transparently adding fault tolerance in mobile distributed systems, Minimum-process coordinated checkpointing is preferable but it may require blocking of processes, extra synchronization messages or taking some useless checkpoints. All-process checkpointing may lead to exceedingly high checkpointing overhead. In order to balance the checkpointing overhead and the loss of computation on recovery, we propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. In the minimum-process coordinated checkpointing algorithm; an effort has been made to optimize the number of useless checkpoints and blocking of processes using probabilistic approach and by computing an interacting set of processes at beginning. We try to reduce the loss of checkpointing effort when any process fails to take its checkpoint in coordination with others. We reduce the size of checkpoint sequence number piggybacked on each computation messag

Operative Merest-undertaking Impeccable Reclamation Line Accretion Ordering for Deterministic Mobile Distributed Computing Systems

Impeccable-RL-accretion   (Impeccable Reclamation Line accretion) is one of the ordinarily familiarized  approaches to present failing resilience  in Distributed Computing  setup (DCS)   so that the setup can operate even if one or more components have abdicated. However, Mobile DCSs are constrained by small transmittal potentiality, Suppleness, and dearth of stabilized repository, recurrent disruptions and imperfect battery life. From this time Impeccable-RL-accretion   orderings which have reduced reestablishment-dots   are favored in mobile environments. In this paper, we contemplate a merest-undertaking synchronic ordering for Impeccable-RL-accretion   for mobile DCS. We eliminate inoperable reestablishment-dots   as well as stalling of undertakings amidst reestablishment-dots   at the striving of registering contra-dispatches of very few dispatches amidst Impeccable-RL-accretion. We also organize an effort to subside the depletion of Impeccable-RL-accretion   work when any undertaking collapses to stockpile its reestablishment-dot in a founding. In this mode, we handle excessive failings amidst Impeccable-RL-accretion. We organize registering of contra-dispatches of very few dispatches only amidst Impeccable-RL-accretion. We also strive to subside depletion of Impeccable-RL-accretion   work. &nbsp

Study and Design of Global Snapshot Compilation Protocols for Rollback-Recovery in Mobile Distributed System

Checkpoint is characterized as an assigned place in a program at which ordinary process is intruded on particularly to protect the status data important to permit resumption of handling at a later time. A conveyed framework is an accumulation of free elements that participate to tackle an issue that can't be separately comprehended. A versatile figuring framework is a dispersed framework where some of procedures are running on portable hosts (MHs). The presence of versatile hubs in an appropriated framework presents new issues that need legitimate dealing with while outlining a checkpointing calculation for such frameworks. These issues are portability, detachments, limited power source, helpless against physical harm, absence of stable stockpiling and so forth. As of late, more consideration has been paid to giving checkpointing conventions to portable frameworks. Least process composed checkpointing is an alluring way to deal with present adaptation to internal failure in portable appropriated frameworks straightforwardly. This approach is without domino, requires at most two recovery_points of a procedure on stable stockpiling, and powers just a base number of procedures to recovery_point. In any case, it requires additional synchronization messages, hindering of the basic calculation or taking some futile recovery_points. In this paper, we complete the writing review of some Minimum-process Coordinated Checkpointing Algorithms for Mobile Computing System

THE PERFORMANCE OF SOFT CHEKPOINTING APPROACH IN MOBILE COMPUTING SYSTEMS

Mobile computing raises many new issues such as lack of stable storage, low bandwidth of wireless channel, high mobility, and limited battery life. These new issues make traditional checkpointing algorithms unsuitable. Coordinated checkpointing is an attractive approach for transparently adding fault tolerance to distributed applications since it avoids domino effects and minimizes the stable storage requirement. However, it suffers from high overhead associated with the checkpointing process in mobile computing systems. In literature mostly, two approaches have been used to reduce the overhead: First is to minimize the number of synchronization messages and the number of checkpoints; the other is to make the checkpointing process nonblocking. Since MHs are prone to failure, so they have to transfer a large amount of checkpoint data and control information to its local MSS which increases bandwidth overhead. In this paper, we introduce the concept of “Soft checkpoint” which is neither a tentative checkpoint nor a permanent checkpoint, to design efficient checkpointing algorithms for mobile computing systems. Soft checkpoints can be saved anywhere, e.g., the main memory or local disk of MHs. Before disconnecting from the MSS, these soft checkpoints are converted to hard checkpoints and are sent to MSSs stable storage. In this way, taking a soft checkpoint avoids the overhead of transferring large amounts of data to the stable storage at MSSs over the wireless network. We have also shown that our soft checkpointing scheme also adapts its behaviour to the characteristics of network