What is Amazon Web Services RDS month-to-date usage?

Question

I have one RDS instance on AWS under the free tier, and I've been monitoring the resources I'm using. Under the free tier, I have 20 GB-Mo of RDS - Storage and 750 Hrs of RDS - Instance. I have just one RDS instance, but my Month-end forecasted usage surpasses the free tier limits, even if I'm not even using it (the RDS Instance is active, but I'm not effectively using it for anything yet).

Since I have just one RDS instance active, it doesn't make sense that I'm surpassing RDS instance free tier usage, I think. I just wanted to clarify if those two services (RDS-Storage and RDS-Instance) actually mean what I think (RDS-Storage is the amount of actual storage I'm using from my RDS database and RDS-Instance is the amount of time the instance has been running since the start of the month, right?).

Am I missing anything? (I know that I'm not giving much information, but I'm new to AWS and I don't know which kind of information would be useful)

It kind of looks like you either have two RDS instances, or you enabled a read replica when you created your RDS instance, which would create another instance. Same for if you enabled Multi AZ. Log into the AWS console, go to the RDS console in the region where you created the database, and find your instance. Expand its information and see what's configured under the section Availability and Durability. — wkl
@birryree I only have one RDS instance and it's not Multi AZ. My instance is a db.t2.micro 20 GB storage. How do I know if a read replica is enabled? — tropez
@Vinicius you need to check all regions. A replica is a separate instance, so if you have one, you'll see another RDS instance. It definitely looks like you have a total of two, or one Multi-AZ, if you have already run up 740 machine hours. — Michael - sqlbot
@Michael-sqlbot Yeah, you are right! I tottaly forgot that I had another RDS instance running on another region (and I forgot to delete it). Thank you for the hint! — tropez

ExploringApple ExploringApple · Accepted Answer · 2017-11-16T14:28:05

AWS only can answer this question and here is their explanation.

The "Forecast" function is designed to be a rough prediction of your monthly AWS usage, based on your month-to-date charges.

Although most AWS services bill on-demand, meaning your overall bill steadily increases over the course of a month, some services or features bill a larger amount once, usually on or near the first of the month.

This might cause your forecasted usage to appear higher than you expect at the beginning of a month, because your average daily cost is higher at the beginning of the month than it will be over the course of that month. As the month progresses, your usage should normalize, and the forecast will be a more accurate prediction of your final monthly bill.

What is Amazon Web Services RDS month-to-date usage?

1 Answers