It really isn’t trivial to understand Amazon’s charges and sometimes it can raise questions. Remember that costs are always calculated based on usage. Cloud8 takes estimates directly from Amazon itself, to avoid making calculations in parallel and thus providing the most accurate estimate possible.
We use two ways to calculate costs:
- Cost estimates: we pull data from CloudWatch;
- CSV report of detailed items: we compute the daily cost;
Cloud8 will try to use the CSV report, but we are unable to enable it, CloudWatch is used.
See the advantages and disadvantages of each:
| Feature | CloudWatch | CSV Report ** |
| Precision | Variable | Very close to 100% |
| Punctuality | Always available | Sometimes late |
| Daily cost | Variable | Precise |
It is worth paying attention to some points:
- Amazon always charges for the closed month (that is, from the first to the last day of the month);
- When using CloudWatch, it is common for Amazon to stop calculating estimates for a few hours and even 1 to 3 days – the daily cost drops to close to zero and then when it resumes the calculations, it seems to spike. But if you average these days, you will see that the spending curve remains constant.
- costs are calculated based on usage. If you used a server for a few hours and later destroyed it, the cost calculated will be the hours used based on the chosen size and operating system;
- for components such as disks, backups, files (S3), etc., costs are proportional within the month. For example, if you placed the files on S3 in the last days of the month, you will be charged fractions of US$0.095/GB;
- for components such as notifications, SQS (queues), emails, etc., the costs are based on quantities. Ex: for emails the cost is US$0.10 for 1,000 emails sent (without attachments);
- be aware of some services that are free to use – after the included level, charging begins;
- Even so, if you think there is something wrong, you can contact them using this form:
https://aws.amazon.com/support/createCase?type=account_billing
Finally, it is always important to have all billing reports and estimates enabled. This greatly helps the diagnosis. Follow the steps to enable them:
https://cloud8.io/docs/hot-to-enable-cloud-cost-estimates-monitoring/
