CTERA reckons Amazon S3’s price complexity drives customers mad

CTERA’s CTO, Aaron Brand, declares AWS S3’s pricing scheme “is anything but simple” and “frustratingly expensive” to transition your objects between storage classes. In fact, “this complexity is driving their customers mad”.

Update. CTERA has updated its S3 storage costs blog to reflect S3 price model changes announced on AWS Storage Day 2021. That makes the comparison data here invalid. Check out the CTERA blog for the new comparisons. 15 Sep 2021.

CTERA is a company that provides cloud-based file services including collaboration and security.

These are the concluding remarks in a blog in which he discusses S3’s three main storage classes, recurring fees and per-operation fees. 

* Assuming the object is uploaded to “S3-Standard” and then transitioned using storage lifecycle.

The three classes are: Standard, Infrequent Access, and Intelligent Tiering. Brand says: “All these storage classes offer identical performance, so, the choice between them does not depend on the level of performance.”

Aaron Brand.

In Brand’s view, “S3 standard is always more cost effective in storing objects smaller than 128KB. If your application stores many small objects, keep those in S3 standard.“

Although Infrequent Access is cheaper than Standard, the Put, Get and Retrieve operations cost more. Brand has an ROI model to calculate whether it is worthwhile keeping a group of objects in Standard or Infrequent Access.

This takes into account:

  • The upfront cost (the cost of the PUT operation and lifecycle transition); 
  • The fixed monthly ongoing costs (the per-GB cost); 
  • The variable costs (the cost of data retrievals). 

He worked out the costs and ROI in months for sets of objects with average object sizes of 128KB, 250KB, 1MB and 4MB:

In his view, “As a rule of thumb, for objects of 1MB or larger, S3-IA is recommended if the number of monthly retrievals per object is 0.7 or less. For smaller objects, be very careful, as anything more than one yearly retrieval may result in a negative return on investment.”

Brand says “S3 Intelligent Tiering charges you a fixed and predictable management fee based on the total number of objects. This management fee of $2.5 per million objects, per month, is insignificant when dealing with large objects but may be cost prohibitive for smaller objects.”

Brand concludes that the S3 pricing scheme is expensive, and working out costs of transitioning objects between storage classes is frustrating.

The main takeaway is that the important thing for keeping S3 costs as low as possible is not using it to store small objects. “By putting high price tags on metadata operations, AWS is severely penalising workloads consisting of numerous operations on small objects.”

His recommendation is to keep your S3 stored objects 1MB in size or larger.