Praveen Choudhary et al., International Journal of Emerging Trends in Engineering Research, 9(8), August 2021, 1069 – 1072 1069 Low-Overhead Minimum-Method Global Snapshot Compilation Protocol for Deterministic Mobile Computing Systems Praveen Choudhary 1 , Parveen Kumar 2 1 Research Scholar, NIMS University, Jaipur, India, praveenchoudhary0@gmail.com 2 Professor, Dept. of Computer Sc. & Engineering, NIMS University, Jaipur, India, parveen.kumar@nimsuniversity.org ABSTRACT CGS-accumulation (Consistent Global State Accumulation) is one of the commonly used method to provide fault tolerance in distributed systems so that the system can operate even if one or more components have failed. However, mobile computing systems are constrained by low bandwidth, mobility, lack of stable storage, frequent disconnections and limited battery life. Hence CGS- accumulation etiquettes which have lesser reinstatement- points are favored in mobile environment. In this paper, we propose a minimum-method coordinated CGS-accumulation etiquette for deterministic distributed applications on mobile computing systems. We eliminate useless reinstatement-points as well as blocking of methods during reinstatement-points at the cost of logging anti- messages of very few messages during CGS-accumulation. We also try to minimize the loss of CGS-accumulation effort when any method miscarries to capture its reinstatement-point in an instigation. In this way, we take care of excessive disappointments during CGS-accumulation. We make logging of anti-messages of very few messages only during CGS-accumulation. We also strive to minimize loss of CGS-accumulation effort. Key words: Anti-message, CGS-accumulation, Deterministic Systems, Distributed Systems. 1. INTRODUCTION Reinstatement_point is a way to add fault tolerance into computing system. It essentially consists of saving a snapshot of the application state, in order that it is able to restart from that point in case of failure. A reinstatement_point is a local state of a method saved on stable storage. By periodically invoking the CGS-accumulation procedure, one can save the status of a program at regular intervals [1], [2]. If there is a disappointment, one may restart computation from the last reinstatement-points, thereby, avoiding reiterating computation from the commencement. The method of recommencing computation by rolling back to a saved state is called rollback recovery [3]. In a distributed system, since the methods in the system do not share memory, a global state of the system is defined as a set of local states, one from each method. The state of channels corresponding to a global state is the set of messages sent but not yet received [4]. In deterministic Mobile_DS(Mobile Distributed Systems), if two procedures start in the identical state, and both receive the undistinguishable sequence of inputs, they will yield the duplicate sequence of outputs and will commit in the similar state. The state of a procedure is thus entirely determined by its opening state, received communications, and by order of communications it has method [5], [6]. Johnson and Zwaenepoel[5] projected sender-based communication- logging for deterministic systems, where each communication is registered in volatile memory on the machine from which the communication is directed. The communication-log is then autonomously written to the stable storage, without suspending the computation, as part of the sender’s periodic resident-reinstatement-point. Johnson and Zwaenepoel [6] used optimistic communication-logging and CGS- accumulation to determine the most recent recoverable state, where every received communication is registered. David R. Jefferson [7] presented the concept of anti-message. Anti- message is precisely like an original communication in format and content except in one field, i.e., sign. Two communications that are indistinguishable except for opposite signs are called anti-messages of one another. All communications directed unambiguously by user programs have a positive (+) sign; and their anti-messages possessed a negative sign (-). Whenever a communication and its anti- message takes place in the same queue, they instantaneously cancel one another. Thus, the result of adding a communication to a queue may be to abbreviate the queue by one communication rather than lengthening it by one. We portray the anti-message of m by m -1 . In this paper, we suggest a min-method synchronized CGS-accumulation scheme for deterministic Mobile_DSs. We eradicate inoperable reinstatement_points as well as hindering of procedures during CGS-accumulation at the cost of logging anti-messages of very few communications during CGS- accumulation. 2. SYSTEM MODEL FOR PROPOSED ETIQUETTE In this paper we used the system model presented in [8]. In this model, a mobile computing system consists of n mobile hosts (Mob_Nodes), and m mobile support stations (Mob- Supp-Sts), where n > m. A cell is a logical or geographical ISSN 2347 - 3983 Volume 9. No. 8, August 2021 International Journal of Emerging Trends in Engineering Research Available Online at http://www.warse.org/IJETER/static/pdf/file/ijeter06982021.pdf https://doi.org/10.30534/ijeter/2021/06982021