An IT firm has deployed a legacy application on an Amazon EC2 instance. The Operations Team wants to analyze custom metric data for this application which was published 30 days back with a standard resolution to Amazon CloudWatch. Team Lead is concerned about the resolution of metric data.
Which is the correct statement depicting the resolution of metric data?

Answer options:

A.Metric Data will be retrievable with a resolution of 60 mins.
B.Metric Data will be retrievable with a resolution of 15 mins.
C.Metric Data will be retrievable with a resolution of 5 mins.
D.Metric Data will be retrievable with a resolution of 1 min.

Correct Answer: C
Amazon CloudWatch retains metric data as follows:
Data points for high-resolution custom metrics. With a period of less than 60 seconds are available for 3 hours.
Data points with a period of 60 seconds are available for 15 days.
Data points with a period of 300 seconds are available for 63 days.
Data points with a period of 3600 seconds are available for 455 days.
Data Points that are published with a shorter period are aggregated to retain for longer periods. In the above case, data was published with a standard resolution of 1 minute 30 days back. So, Amazon CloudWatch will aggregate 1 min data to a resolution of 5 mins (300 secs) and retain it for 63 days. Post 63 days, the resolution will be changed to 1 hour.
Option A is incorrect as only after 63 days, data is aggregated with resolution as 60 mins.
Option B is incorrect as this is an invalid resolution time frame.
Option D is incorrect as Data with a resolution of 1 min is retained only for 15 days. Post 15 days data is aggregated and can be retrieved with 5 mins resolution.
For more information on the retention period for metrics, refer to the following URL,
https://docs.amazonaws.cn/en_us/AmazonCloudWatch/latest/monitoring/cloudwatch_concepts.html