Amazon DocumentDB Overview

We will talk about DocumentDB so we all know about Aurora RDS and Aurora RDS is AWS implementation of Postgresql or MySQL because it has the same API but it's built on AWS and it has some nice benefits to be cloud native.
DocumentDB is the same as Aurora RDS but for MongoDB (Which is NoSQL database).

- Mongodb is used to store, query and index JSON data so thanks to DocumentDB.
- Similar "deplyement concept" as Aurora RDS.
- Fully Managed, highly available with replication across 3 AZ.
- DocumentDB storage automatically grows in increments of 10GB.
- Automatically scales to workloads with millions of requests per seconds.

If using MongoDB on AWS so you pay for what you use in DocumentDB and there is no upfront cost but you need to understand the Architecture of DocumentDB, which is very similar to Aurora in order to understand its pricing.

DocumentDB - Pricing

- Pay as you Go, so pay for what you use. No up front cost.
- On-Demand Instances (pay per second with the minimum of 10 minutes)
- Database I/O: amount of IO used when Read/Write (per million IOs)
- Database Storage (per GB/month)
- Backup Storage (per GB/month)

We have database storage and then we have On Demand instances. We have primary instance and then replica instances that's up to you're going to pay for these on-demand instances, you can pay per second with the minimum of 10 minutes then these instances are going to do a read and write operations against your database storage so you're going to base for database IOs and this going to be counted per million IOs then of course the data is being stored on your database storage and therefore you're going to pay for the derby storage itself in gigabytes per month.