DynamoDB Provisioned RCU Calculation

Answer: A.

Option A is CORRECT.

1RCU is equivalent to one strongly consistent read per second for an item up to 4 KB in size.

Thus, to calculate the required RCU in this scenario, we need to:

1

Round up the item size to the nearest 4KB (8KB)

2

Divide by 4KB to calculate the number of strongly consistent read units (8/4 = 2)

3

Multiple by operations per second to get the total RCU required (2*100 = 200 RCU)

Reference:

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

To calculate the provisioned RCU (Read Capacity Units) required to meet the given requirements, we need to consider the following:

1. Read capacity units (RCU) - It represents the capacity consumed per second by a strongly consistent read operation for an item up to 4 KB in size. For items larger than 4 KB, additional RCUs are required.
2. Write capacity units (WCU) - It represents the capacity consumed per second by a write operation for an item up to 1 KB in size. For items larger than 1 KB, additional WCUs are required.
3. Item size - Each item in the DynamoDB table is 6 KB in size.
4. Number of strongly consistent read operations per second - 100
5. Number of write operations per second - 40

To calculate the provisioned RCU value required for the given scenario, we need to consider the following:

1. For each strongly consistent read operation, the application will consume 2 RCUs as each item is 6 KB in size (i.e., 6 KB / 4 KB = 1.5; 1.5 * 2 = 3 RCUs). Therefore, the total RCUs required for 100 strongly consistent read operations per second is:

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    100 * 3 = 300 RCUs 

2. For each write operation, the application will consume 1 WCU as each item is 6 KB in size (i.e., 6 KB / 1 KB = 6). Therefore, the total WCUs required for 40 write operations per second is:

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    40 * 6 = 240 WCUs 

Thus, the total provisioned RCU value required to meet the given requirements is the higher of the two values calculated above, which is 300 RCUs. Therefore, the answer is option C, i.e., 600 RCU (provisioned RCU value should be set to 600 to meet the given requirements).