RDS: Difference between RX and NetworkReceiveThroughput?

Question

I was analyzing the network performance of the Database we have on RDS, which has enhanced monitoring turned on. I am confused with two metrics (one from enhanced monitoring, another from CloudWatch), that theoretically mean the same, but are showing different values.

For a given time range, 'RX' graph under Enhanced Monitoring says that 3.27 GiB (approximately). And according to the [AWS documentation](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Monitoring-Available-OS-Metrics.html), RX means "The number of bytes received per second.".
![RDS-Console-RX-Value-In-GiB](https://repost.aws/media/postImages/original/IMrOSJwCBaQ9uAoZEfHjNf_Q)

But for the same time range, if you plot 'NetworkReceiveThroughput' in CloudWatch, I see 3.6 million bytes per second (approximately), which is close to 3.6MB per second. And if you look up the [documentation](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/rds-metrics.html) on this term, it says "The incoming (receive) network traffic on the DB instance, including both customer database traffic and Amazon RDS traffic used for monitoring and replication."
![CloudWatch-NetworkReceiveThroughput-Bytes-per-Second](https://repost.aws/media/postImages/original/IMN-ChqNTKQdiG7DZDA0GrEw)

Though NetworkReceiveThroughput is slightly different from RX since it includes AWS internal traffic that transmits monitoring data as well, I should have seen a higher value than RX in my case. Why are these values different by a huge margin? What am I getting wrong?

Answer

Hello,
Thank you for reaching out to us via AWS re:Post - First of all, I would like to thank you for bringing this to our attention.

We have a known bug that the console shows the "units" of RX and TX wrong - this has been reported by other users too and is being checked by the internal team. Since any change in the prod console goes through rigorous testing, auditing etc. we do not have an ETA when this would be released but for now, judging by the screenshots it seems the units in RX and TX are in MB. However, to confirm for your instance - I would recommend you to reach out to AWS Premium Support Team so that they can do a deep dive on the internal metrics for the instance and confirm what I just shared here.

Hope this helps in your project Thank You!

RDS: Difference between RX and NetworkReceiveThroughput?

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