There are different ways to learn and test Amazon DynamoDB on-demand and test how the database process requests without capacity planning. There are conventional ones, where you follow the AWS documentation and “start 1,000 Lambda functions in parallel to generate load on the API endpoint, using random HTTP methods and random data for the item”.

Or you can try a more absurd way to demonstrate how the write capacity and your billing are predictable in an on-demand mode. You can cycle the Tour de France from Briançon to Alpe d’Huez, invoking a Lambda function to generate the required load and match the profile of the stage. Climbing the legendary and gruelling Col du Galibier and Col de la Croix de Fer on two wheels is significantly harder than on DynamoDB.

ConsumedWriteCapacityUnits

Lambda Invocations

The correlation between the ConsumedWriteCapacityUnits that we pay on DynamoDB – as there is no provisioned one – and the Lambda Invocations metrics is pretty striking. And they both match the route we had to cycle.

Conclusions

DynamoDB is indeed elastic but It is just a game, do not take me too seriously. Now go out there and start cycling!