FAULT TOLERANCE Meaning and
Definition
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Fault tolerance is a desirable characteristic in computer systems that ensures their ability to continue functioning in the presence of failures or errors. It is a measure of how well a system can withstand and recover from faults, which may arise due to hardware malfunctions, software bugs, or other external factors.
In a fault-tolerant system, the occurrence of a fault should not lead to a complete system failure. Instead, the system should have provisions to detect, isolate, and recover from faults, ensuring minimum disruption and consistent performance. This can be achieved through a combination of hardware and software techniques.
Hardware fault tolerance involves duplication or replication of critical components, such as processors, memory modules, or disks, so that a backup system can take over in case of a failure. Redundancy and error detection mechanisms, like checksums or parity bits, are employed to detect and correct errors before they cause system failure.
Software fault tolerance involves implementing error-handling and recovery mechanisms within the software itself. This may include techniques like exception handling, checkpointing, and rollback, where the system can recover to a known good state after a fault occurs.
Overall, fault tolerance aims to ensure the reliability and availability of a system, minimizing the impact of failures on its operation and maintaining uninterrupted and consistent service.
Etymology of FAULT TOLERANCE
The term "fault tolerance" is composed of the words "fault" and "tolerance".
The word "fault" originally comes from Old English "fylgan" which means "to deceive or challenge". Over time, it evolved to refer to a defect or mistake, especially in the context of technology or machines.
The word "tolerance" originated from the Latin word "tolerantia", which means "endurance, forbearance". In English, it was initially associated with the ability to endure pain or hardship, and later came to be applied to various contexts including engineering and technology. In the context of fault tolerance, it refers to the ability of a system to withstand and recover from faults or failures.
Therefore, "fault tolerance" essentially means the ability to tolerate and overcome faults or failures in a system or technology.
