DynamoDB Provisioned Throughput Calculation
Question
A DynamoDB table is configured in provisioned throughput mode with 100 RCU and 40 WCU.
How much data can be read and written to the table each second?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer: A.
Option A is CORRECT.
One read capacity unit is equivalent to one strongly consistent read per second, or two eventually consistent reads per second, for an item up to 4 KB in size.
One write capacity unit is equivalent to one write per second for an item up to 1 KB in size.
Therefore, 1000 RCU is equivalent to:
· Strongly Consistent Read operations: 100 RCU * 4KB = 400 KB per second.
· Eventually Consistent Read operations: 100 RCU * 4KB = 400 KB per second * 2 = 800 KB per second.
· Write operations = 40 WCU * 1KB = 40 KB per second.
Reference:
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadWriteCapacityMode.html#HowItWorks.ProvisionedThroughput.ManualTo calculate the amount of data that can be read and written to a DynamoDB table each second, we need to consider the table's provisioned throughput, which is measured in read capacity units (RCUs) and write capacity units (WCUs).
In this scenario, the table is configured with 100 RCU and 40 WCU. This means that the table can perform up to 100 strongly consistent read operations or 200 eventually consistent read operations per second, and up to 40 write operations per second.
According to the AWS documentation, the maximum amount of data that can be read or written per second for each operation is as follows:
- Strongly consistent read operations: 4 KB per RCU
- Eventually consistent read operations: 8 KB per RCU
- Write operations: 1 KB per WCU
Using these values and the provisioned throughput of the table, we can calculate the maximum amount of data that can be read and written to the table each second:
- Strongly consistent read operations: 4 KB per RCU * 100 RCU = 400 KB per second
- Eventually consistent read operations: 8 KB per RCU * 100 RCU = 800 KB per second
- Write operations: 1 KB per WCU * 40 WCU = 40 KB per second
Therefore, the correct answer is A. The table can handle 400 KB of data for strongly consistent read operations, 800 KB for eventually consistent read operations, and 40 KB for write operations per second.
