DynamoDB Provisioned Throughput Calculator

How many WCUs do you need for your DynamoDB table?

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Question

You are developing a gaming application that needs to write 100 items every second.

Each item is of 2KB containing session data and game data.

How many WCUs do you need to provision for your table?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

Correct Answer: D.

1 WCU provides 1KB write per second.

Items to write every second: 100

To write one item, we need: 1*2=2

Hence, we require 2 WCUs to write one item.

Total WCUs required: 2*100 = 200

Option A, B and C are incorrect since they are not the required WCUs to perform the above operation.

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadWriteCapacityMode.html

To determine the WCU (Write Capacity Unit) required for the given scenario, we need to first calculate the total data size that will be written per second.

100 items per second, each item containing 2KB of data, therefore: Total data size per second = 100 * 2KB = 200KB/s

Next, we need to calculate the WCU required to handle this amount of data.

One WCU can handle up to 1 KB of data per second, so we need to divide the total data size per second by 1KB to get the required number of WCUs.

WCU required = (200KB/s) / (1KB/WCU) = 200 WCUs

Therefore, the answer is D. 200.

We need to provision 200 WCUs to handle the write capacity for the gaming application to write 100 items every second, each item containing session data and game data of 2KB size.