Database

Amazon DocumentDB

Timebilled
Bytesbilled
Callsbilled

In one line

Billing mirrors Aurora: instance-hours, cluster storage, and I/O per million.

What gets missed

Cross-AZ replication inside a multi-AZ cluster is free. Elastic clusters bill vCPU-hours rather than instance-hours and Serverless bills DCU-hours, and an I/O-Optimized option removes the I/O meter entirely.

Find it on your bill

Filter Cost Explorer or your Cost and Usage Report by these usage types. A usage type with no region prefix means us-east-1.

InstanceUsage
InstanceUsageIOOptimized
StorageIOUsage
ElasticCPUUsage

Bills the same way

These services turn exactly the same meters, so what you learn here transfers.