Fault tolerance: An approach toward a hybrid fault tolerance framework within a distributed computer architecture

Abstract

The increasing reliance on technical systems to achieve a desired level of organisational performance has significantly decreased the margin for system-related errors. The greater the number of interactions encountered by technical systems to provide the required functionality, the greater the fault exposure. These faults refer to the falling of a system into an undesirable state, hereafter referred to as failure. Faults may occur by many means, including malicious cyberattacks, bugs and malfunctions at component level. System failure often leads to substantial pecuniary losses and poses a high threat to system security owing to vulnerability (Castro and Liskov, 2002). To mitigate these issues, a hybrid fault framework is proposed. Through the implementation of a hybrid approach, where redundancy and consensus-based evaluation are implemented together as fault tolerance measures, system resilience will be greater when posed with failures. A network was created with three computers and security measures emplaced including Snort rules and an uncomplicated firewall. Thereafter, Pings, Port Scans and Denial of Service (DOS) attacks were performed in an attempt to induce a state of system failure with subsequent responses documented. One of the computers acted as a server, one as a user of the server, and one as an attacker. The Mean Time to Failure, Mean Time to Repair and Availability metric were used to monitor the effect on the network. It became evident that the computers faced strain and that if fault tolerance measures were emplaced, the computers would have responded to the attacks more efficiently. The metrics calculated indicated the need for fault tolerance in a system owing to the large discrepancies as the attacks occurred. To aid an infallible system, the implementation of a hybrid fault tolerance framework is necessary. Through the inclusion of Redundancy and consensus-based fault tolerance, which includes blockchain usage, the framework will result in resilient systems allowing various corporate ecosystems a safeguard against a multitude of system related issues.