Amazon S3 Glacier is a low-cost, long-term online file storage and archival facility that serves a lot like cold storage for online files. It is most suitable for files that are not accessed frequently. It is a secure and durable data backup and archival facility for businesses, organizations, and governments.

However, as easy as it sounds to use Amazon S3 Glacier, the billing is not simple. Much of the confusion about the billing and pricing arises from the pricing structure of storage and retrieval. Glacier offers a range of charge options and a few hidden charges like deletion charges. This article addresses the various complexities of Amazon S3 Glacier's charges and payment breakdown.

AWS Storage Pricing

Amazon S3 Glacier can reliably store TBs of essential data for months and even years. It is free to upload an unlimited amount of data; it charges per gigabyte per month for storage facilities. You do not have to buy storage in advance or pay an upfront fee. It charges as low as $0.004 per GB stored per month, but the charges may vary depending on your region. However, it isn't that simple as Glacier charges change depending on your file's size, how long you store it, and the storage class you choose. There are seven types of storage options, depending on your usage, and it isn't easy to understand precisely how you are being charged.

AWS S3 Glacier Retrieval Pricing

Amazon S3 Glacier archives the stored data, which can easily be retrieved. There is a two-step process in retrieving archives from the Glacier. First, you initiate a job request, and once it is processed, you can download the bytes. They charge you per GB and per job request per archive. Phew. There's more. There will be a fee per GB of the data retrieved, and if you asked for ten archives, you would also be charged per archive. Furthermore, Amazon Glacier S3 allows the user three ways to access and retrieve their data -expedited, standard, and bulk.

Retrieval Request Pricing

Bulk retrievals costs $0.025 per 1,000 requests, standard costs $0.05 per 1,000 requests, and expedited retrievals cost $10 per 1,000 requests. This is where most users find it difficult to calculate charges in advance and end up paying more than they had thought.

Retrieval Pricing per GB

Expedited retrieval can be done in 1-6 minutes; standard retrieval time for a file is between 3-5 hours, whereas bulk retrieval can take 5 to 12 hours.

One may end up making erroneous calculations due to the three different ways of retrieving data. The retrieval price for data in bulk is $0.0025 per GB, the Standard time is $0.01 per GB, and expedited is $0.03 per GB. There is an AWS free tier, which allows free retrieval of data up to 10 GB that can be used for the month. But this only applies to Standard retrievals.

Data Transfer Pricing

Amazon does not charge you for data transfer into Amazon Glacier. It does not charge for data transfer OUT of Amazon to the Internet up to 1 GB per month only. But, after 1 GB till 9.99 TB, the charges are $0.09 per GB. After that, it charges $0.085 for the next 40 TB in a month and so on. Data transfer out to Amazon CloudFront is free of cost, whereas GovCloud and other regions are between $0.01-0.02.

There are no charges for data transfer between Amazon EC2 and Amazon S3 Glacier within the same region.

Data Deletion Pricing

While it is free to delete data from Amazon Glacier, early deletion is not. Some users call it Amazon's 'hidden charges,' whereas it is written in their FAQs section. If a user deletes data within 90 days of uploading it, they will charge you a prorated early deletion fee. Amazon S3 Glacier is a long term archival and data storage solution, so it can store your data for decades and thus charges if a file is deleted within three months of being stored on it. An example of deletion billing is such that if you delete 1GB data 30 days after uploading, the early deletion fee will be $0.008, but if you deleted it after 60 days, it would be $0.004 per GB.

It is essential to read the Amazon S3 Glacier FAQs before you transfer or request data. Ensure that you have understood the pricing breakdown and the different ways that Amazon Glacier can charge you. These FAQs give additional tips on the best practices to ensure that you are not charged extra or ways you can cut the bill. For example, it is recommended that you aggregate your data when ingesting files to avoid build-up of data and thus a higher storage per GB bill. Also, keep in mind that there are 32 Kilobytes overhead for every GB of storage.

Amazon S3 Glacier's billing seems deceptively easy, but it is not. Especially when a user has not researched and read through the Pricing FAQs and page thoroughly. The solution is to read through the fine print and read other user's reviews. You could also use software that calculates billing and helps use AWS products and features.