Load Testing · Senior · Question 73 of 76
The DB is at 40% CPU but has high I/O wait under load. What is the likely bottleneck?
- 1Disk I/O: queries wait for reads or writes, not for CPU
- 2The CPU, because 40% is already near saturation
- 3The network between the app and the load generator
Show the answer
Correct answer: Disk I/O: queries wait for reads or writes, not for CPU
Explanation
High iowait means the disk can't keep up: missing indexes, a too-small buffer cache or slow storage. USE metrics for the disk confirm it.