Introduction
Hi, welcome to the second lesson of Unit 4 for AP CSP. This is a very short but important lesson!
The main purpose of this article is to cover the material in the AP CSP CED.
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CSN-1.E: For fault-tolerant systems, like the Internet:
- a. Describe the benefits of fault tolerance.
- b. Explain how a given system is fault-tolerant.
- c. Identify vulnerabilities to failure in a system.
Fault Tolerance
In the last lesson, we learned about how the Internet transmits information through packets. These packets are routed through devices on the network, or a node. A major characteristic of the Internet is that it has been engineered to be fault-tolerant. This means that if one node of the Internet fails, data can still go from its beginning location to its end. A real-world example of this is a city’s road system. Usually, there will be multiple paths that can be taken from one location to another. This means that if a certain path is blocked due to a crash or bad weather, people can still get to where they need to be (although with a little more traffic).
Redundancy
Redundancy is defined by CollegeBoard as “the inclusion of extra components that can be used to mitigate failure of a system if other components fail.” The previous example of the road system was an example of redundancy. Having multiple paths between locations allows data or cars to arrive where they need to be. In the event that a server goes down, data can be redirected as needed- preventing a total system failure.
And that’s it for lesson 4.2!