CISSP Made Easy

🎯 #CISSP Tips

🎯 Fault Tolerance vs. System Resiliency

🎤 Words have some intrinsic meanings, and based on its genesis (etymology) it inherits certain story/context. Interestingly, at times while language evolves and is conditioned across different cultures, meanings of words also travels in the invisible cosmos of human consciousness, making it a subject of change over times.

📚 CISSP demands the visualisation of definitions in certain context. Take the example of MTTF. MTTF is a rough indication of End-Of-Life of a system. However in CISSP-verse this is taken in the context of “backup tapes” indicating “the number of times a tape can be reused before removing it from the service”. This context confirms the EOL definition, but is more specific. Moreover you get the mental picture in your mind to stick this term with a magnetic tape.

🍀🌻🌴 This is crucial to know the “context” if we wish to pass the exam. Context for the definitions helps you to have a story in mind which keeps the definition alive. If you lose the story, you lose the definition. Think of the definition as a “fish” and the story as a nice “aquarium”. You lose the aquarium, you lose the fish. Think again, what mental picture you get when someone speaks BCP, DRP, IRP etc. If you do not get a picture, your definitions is bound to get forgotten over time.

🦠 ✈️ Past few years were all news with COVID and travel restrictions. Coming back to the topic with some relevant example. If you get COVID virus exposed to you and your fitness is intact, it means you have COVID tolerant immunity. However, if you get ill and got recovered, we can say that you have COVID resilient health. Similarly, a twin-engine aeroplane is a fault tolerant system, in a way if one engine fails, other engine will take over. This makes the aeroplane a crash resilient transport in the context of engine failure. You will realise with these examples that system resiliency is dependent on its component’s fault tolerance. I can safely say that resiliency is a function of tolerance.

Resiliency = f (tolerance)

🧮 This makes tolerance an independent variable, without it resiliency will not be possible. This interdependence is something I came up with and you can comment if you feel some example of tolerance free resiliency.

🪐 In CISSP-verse, talking about disks-mirroring is a fault tolerance feature, which will give rise to system resiliency for data availability. You may also think of dual power supply as a power fault tolerant mechanism which will give rise to system resiliency to power outages. I hope this make sense. You can provide feedback if you feel otherwise.

🧎‍♂️Thinking on the same line, a quote just took shape in my mind: You are resilient to self destruction if you have high tolerance to anger. Think and be cool while preparing CISSP. Happy Learning.

#cissptraining