AWS DevOps Engineer Professional Practice Test

For an application reading and writing to a DynamoDB table at high throughput, what provisioned capacity should be set for a 12 kb item?

1. 200 read capacity units and 600 write capacity units

2. 400 read capacity units and 300 write capacity units

3. 300 read capacity units and 600 write capacity units

4. 150 read capacity units and 150 write capacity units

The correct answer is: 300 read capacity units and 600 write capacity units

To determine the correct provisioned capacity for an application using DynamoDB that handles high throughput with a 12 KB item, it's important to understand how DynamoDB calculates read and write capacity units. For read operations, DynamoDB measures the size of the item being read. A single read capacity unit allows for one strongly consistent read of an item up to 4 KB in size. Since the item is 12 KB, it would consume 3 read capacity units (12 KB / 4 KB). In a high-throughput scenario, if your application requires a specific number of strong reads per second, you can multiply that number by the read capacity units needed per item. The same calculation applies for write operations: one write capacity unit allows writing an item up to 1 KB in size. Thus, a 12 KB item would consume 12 write capacity units (12 KB / 1 KB). Based on this understanding, an application might require significant capacity. For instance, if a reasonable high throughput requirement is set, you would ratio the number of reads and writes that the application expects. Given these calculations, the selection that highlights a substantial amount of read (300) and write (600) capacity units is suitable for scaling and ensuring that the application