Is There a Better AWS Alternative to DynamoDB for a Simple Binary File Store

Question

We are implementing a 'trusted client' model in our mobile app where the server just stores 'blobs' and has no knowledge of their content, other than the version number.

The blobs can be used for static data and saved user data. We need to be ready to store 100 million of these blobs. There will be more writes than reads. The blobs average about 20KB.

Was wondering what sort of problems we might run into using DynamoDB and whether there was something more suitable.

Answer 1

Dynamo could work with this:

• 400 KB max item sizes would work fine for your small blobs
• Binary data types

A few other things to consider with your choice:

• Versioning of items. You mentioned version number in your description, but if you have other versioning requirements, you would want to evaluate those needs as well. (S3 has object versioning, while DynamoDB would have to use a versioning attribute)
• Capacity usage in DynamoDB based on your item sizes - since each item would be ~20 KB, you should factor the actual throughput consumption your application would have
• Multi-region needs. S3 added support for cross-region replication, while DynamoDB does not have anything for this yet
• Costs with your access patterns

Answer 2

S3 would be an excellent place to store the blobs. You can use DynamoDB to hold information about them along with their S3 key names.

These blobs are so small that DynamoDB or RDS could handle them fine, too.