AIncorrect
Tight coupling
Tight coupling is a design where components depend directly on one another.
If one stops, the other is affected and tends to stop too, which is the opposite of this question's queue-based decoupling, so it is incorrect.
Which design concept describes placing a queue between two components of an application so that, even if one component stops, the other can keep processing?
1 / 1
Select an answer
CorrectB
Explanation
Choosing the design concept that decouples component dependencies with a queue.
- 1「placing a queue between two components」Communicate asynchronously through a queue rather than by direct calls
- 2「even if one component stops」Failures must not cascade to the other side
- 3「keep processing」Messages are retained and can resume after recovery
BCorrect
Loose coupling
Correct. Loose coupling is a design that places a queue (such as SQS) between components to reduce direct dependency. Even if the receiving side stops, messages are held in the queue and processing can resume after recovery. Because failures are contained in one place, availability improves.
CIncorrect
Vertical scaling
Vertical scaling is a technique of boosting the performance of a single server (the number of CPU cores and clock speed, the amount of memory, and so on) — scale-up.
It is unrelated to decoupling dependencies between components, so it is incorrect.
DIncorrect
Single point of failure (SPOF)
A single point of failure is the name of a problem — a place where, if it breaks, the whole system stops.
It is the opposite of the design concept of isolating failures with a queue, so it is incorrect.
Key Takeaway
'Insert a queue', 'isolate failures', and 'keep going even if one side stops' point to loose coupling. SQS / SNS are representative. It is contrasted with tight coupling (direct dependency), which risks cascading failures.