Read and write capacity units in DynamoDB - Mini Project: Build & Apply

Manage Read and Write Capacity Units in DynamoDB

📖 Scenario: You are managing a DynamoDB table for an online bookstore. To keep the database fast and cost-effective, you need to set the right read and write capacity units.

🎯 Goal: Learn how to create a DynamoDB table with specific read and write capacity units, then update those units as needed.

📋 What You'll Learn

Create a DynamoDB table named Books with a primary key ISBN (string).

Set the initial read capacity units to 5 and write capacity units to 10.

Create a variable called new_read_capacity and set it to 8.

Create a variable called new_write_capacity and set it to 15.

Write the code to update the Books table's provisioned throughput to the new capacity units.

💡 Why This Matters

🌍 Real World

Managing read and write capacity units helps keep DynamoDB tables responsive and cost-effective in real applications like online stores.

💼 Career

Understanding capacity units is important for database administrators and backend developers working with AWS DynamoDB to optimize performance and cost.

1

Create the DynamoDB table with initial capacity units

Create a DynamoDB table named Books with a primary key called ISBN of type string. Set the read capacity units to 5 and write capacity units to 10.

DynamoDB

# Create the DynamoDB table with specified capacity units
# Your code here

Need a hint?

Use dynamodb.create_table with ProvisionedThroughput to set capacity units.

2

Set new capacity unit variables

Create two variables: new_read_capacity set to 8 and new_write_capacity set to 15.

DynamoDB

import boto3

dynamodb = boto3.resource('dynamodb')

Books = dynamodb.create_table(
    TableName='Books',
    KeySchema=[{'AttributeName': 'ISBN', 'KeyType': 'HASH'}],
    AttributeDefinitions=[{'AttributeName': 'ISBN', 'AttributeType': 'S'}],
    ProvisionedThroughput={'ReadCapacityUnits': 5, 'WriteCapacityUnits': 10}
)
Books.wait_until_exists()

# Create variables for new capacity units
# Your code here

Need a hint?

Just assign the numbers to the variables as shown.

3

Get the existing table resource

Get the DynamoDB table resource for the Books table using dynamodb.Table('Books') and assign it to a variable called table.

DynamoDB

import boto3

dynamodb = boto3.resource('dynamodb')

Books = dynamodb.create_table(
    TableName='Books',
    KeySchema=[{'AttributeName': 'ISBN', 'KeyType': 'HASH'}],
    AttributeDefinitions=[{'AttributeName': 'ISBN', 'AttributeType': 'S'}],
    ProvisionedThroughput={'ReadCapacityUnits': 5, 'WriteCapacityUnits': 10}
)
Books.wait_until_exists()

new_read_capacity = 8
new_write_capacity = 15

# Get the table resource for 'Books'
# Your code here

Need a hint?

Use dynamodb.Table('Books') to get the table resource.

4

Update the table's provisioned throughput

Use the update method on the table variable to set the ProvisionedThroughput with ReadCapacityUnits equal to new_read_capacity and WriteCapacityUnits equal to new_write_capacity.

DynamoDB

import boto3

dynamodb = boto3.resource('dynamodb')

Books = dynamodb.create_table(
    TableName='Books',
    KeySchema=[{'AttributeName': 'ISBN', 'KeyType': 'HASH'}],
    AttributeDefinitions=[{'AttributeName': 'ISBN', 'AttributeType': 'S'}],
    ProvisionedThroughput={'ReadCapacityUnits': 5, 'WriteCapacityUnits': 10}
)
Books.wait_until_exists()

new_read_capacity = 8
new_write_capacity = 15

table = dynamodb.Table('Books')

# Update the table's provisioned throughput
# Your code here

Need a hint?

Use table.update(ProvisionedThroughput={...}) with the new capacity variables.