I was reading up on Scaling in DynamoDB. I understand it reads in 4KB increments and I know that math (esp the ones taught in certifications).

So hypothetically iF I have to design a system like TWITTER which can contain 1 million requests per second (RPS) average size of each item about 20KB, can dynamodb support this?

A bit more: 20KB implies 20KB/4KB = 5 RCUs for standard read requests (not eventual consistent for the sake of the argument). How do I correlate this RCU figure of 5 to a million TPS?

CodePudding user response：

Yes, DynamoDB supports some of the highest-scale sites on the internet. Amazon published some metrics about Prime Day load.

https://aws.amazon.com/blogs/aws/amazon-prime-day-2020-powered-by-aws/

Amazon DynamoDB powers multiple high-traffic Amazon properties and systems including Alexa, the Amazon.com sites, and all Amazon fulfillment centers. Over the course of the 66-hour Prime Day, these sources made 16.4 trillion calls to the DynamoDB API, peaking at 80.1 million requests per second.

If you have a million RPS and each request is for 20 KB and you want them strongly consistent then you'd need to provision 5,000,000 RCU. If you're curious, you can calculate the cost based on us-east-1 pricing https://aws.amazon.com/dynamodb/pricing/provisioned/ which is $0.00013 per RCU-hour provisioned, so that's $650 per hour.

Write capacity and data storage have separate pricing.