Load Testing · Senior · Question 6 of 76
Throughput rises with servers, then falls when more are added. Which model explains this?
- 1The Universal Scalability Law: coherency costs grow with node count
- 2Little's law: concurrency equals rate times time
- 3Amdahl's law: the serial part shrinks as nodes are added
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Correct answer: The Universal Scalability Law: coherency costs grow with node count
Explanation
Amdahl only predicts a plateau. With crosstalk between nodes (cache coherence, distributed locks), USL predicts a peak and then decline.