One plug, one office
An office has two web servers and two internet lines. Everything runs through one small switch in a cupboard.
A cleaner knocks the switch's power lead out. The whole office stops.
All that spare kit did not help. Today you learn to find the one part that everything depends on.
By the end of this lesson
Note
I can find a single point of failure and say which systems are critical.
Key words
| Word | What it means |
|---|---|
| Single point of failure | one part that, if it fails, stops the whole system |
| Mission essential function | a job the organisation must keep doing or restart fast after trouble |
| Critical system | a system the mission essential functions depend on |
| Dependency | something else a system needs to work |
| Spare | a second part ready to take over |
| Disruption | a break in normal work |
The cells students fill in are left blank in this preview.
Starter
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Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
A single point of failure
A single point of failure is one part that everything depends on and that has no spare. If it fails, the whole system fails.
It can come from design, from how a system was built, or from its settings. Spare parts only help when every important step has one.
Check
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3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.