Exam AWS Certified Solutions Architect - Professional topic 1 question 42 discussion

Yes, C is Correct!

C is correct

C. Use smaller instances that have higher aggregate I/O performance.

Files are on S3 so it is network not I/O so C is out. To reduce duration of a job, reduce the file size, it will make individual jobs/batch faster. It will use more cpu but we have lots of it so that is fine. Increasing file size would reduce overall (daily) cpu usage but each job runtime will take longer as it will have more data to process

C is more logic

C is best fit

C. D is wrong larger files slow down the performance A is wrong smaller files but more files slow down the performance

Create fewer, larger files on Amazon S3 is to get the better CPU performance, here in question we already have CPU idle so can't be the answer.

C Correct

C. Since I/O is the bottleneck

C is the correct one

It talks about cost efficient way to reduce processing time. Having a server that is mostly idle means several smaller instances could help speed it up ?

It feels like A. "instances that have higher aggregate I/O performance" is all about EBS, isn't it? Reading from S3 only uses network, so why does high IO performance instances have anything to do with S3?

C is correct

I would definitely go with D.

" the most cost efficient way to reduce the runtime of the job" --> D. Create fewer, larger files on Amazon S3.

C is correct