Over the past week, I have been keeping a close eye on my AWS billing log so as to determine which services have charging me without my knowledge.
On the 14/4/2017, I received an EC2 alarm that I was able to determine that it came from the EBS service. To my knowledge, that was the cause of credit expenditure, so I shut it down.
However, I received another alarm notification on the 17/4/2017, this time in regards to my RDS budget.
This concerned me, as I had removed my instances from being Multi-AZ enabled, which meant that I was running them from the free tier. To gain more understanding, I looked through the billing specifics for the RDS service.
What I determined, was that my instances were being charged under the North Virginia region. Due to my assumption that they were running completely within the free-tier conditions, I was not using best practices, and was keeping my instances running while not in use. I had not considered that my decision to have them backed up in another region would invoke a fee.
My next move, was to snapshot and delete my main instance. I chose not to delete the replica immediately, as in my previous experience with backing up and restoring instances, I had found the replica to be more difficult to re-establish during the restoration process.
I checked my bills the next morning to find that the running replica instance was still charging my account. I then proceeded to take a snapshot of the instance, then delete it. My concern for unnecessary charges took precedence over the increased difficulty for restoration. The following screenshot shows the billing amount for the RDS service in North Virginia.
I then took another screenshot later in the day to check whether there was any increase in the billing amount.
The lack of increase confirmed that it was the two running instances that were causing my credit to be charged.
Just in case there were any other expenditures that were increasing my bill, I also checked the overall billing amount during the course of the day, Once at 11:45am and once at 01:25pm. I saw no increase in the overall budget. This meant that I had managed to resolve all of the unnecessary expenditures.