Time to live (TTL) for expiration in AWS - Mini Project: Build & Apply

Time to live (TTL) for expiration

📖 Scenario: You are managing a cloud database where data should automatically expire after a certain time to save space and keep information fresh.Imagine a library where books are borrowed and must be returned after a fixed period. Similarly, data entries will have a 'time to live' (TTL) that tells the system when to delete them.

🎯 Goal: Create a DynamoDB table with a TTL attribute that automatically deletes expired items.

📋 What You'll Learn

Create a DynamoDB table named LibraryBooks with a primary key BookID of type string.

Add a TTL attribute named ExpirationTime to the table configuration.

Set the TTL attribute to enable automatic expiration of items.

Use AWS CloudFormation syntax for the configuration.

💡 Why This Matters

🌍 Real World

TTL is used in cloud databases to automatically remove outdated data, saving storage and improving performance.

💼 Career

Understanding TTL configuration is important for cloud engineers and architects managing scalable, cost-efficient databases.

1

Create DynamoDB table resource

Create a DynamoDB table resource named LibraryBooks with a primary key attribute BookID of type String in AWS CloudFormation YAML syntax.

AWS

# Your code here to create the DynamoDB table resource

Need a hint?

Define the DynamoDB table with Type: AWS::DynamoDB::Table. Use AttributeDefinitions and KeySchema to set the primary key.

2

Add TTL attribute name configuration

Add a TimeToLiveSpecification property to the LibraryBooks resource with AttributeName set to ExpirationTime.

AWS

Resources:
  LibraryBooks:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: LibraryBooks
      AttributeDefinitions:
        - AttributeName: BookID
          AttributeType: S
      KeySchema:
        - AttributeName: BookID
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
# Add TimeToLiveSpecification with AttributeName ExpirationTime here

Need a hint?

Use TimeToLiveSpecification inside Properties to specify the TTL attribute name.

3

Enable TTL for the attribute

Add Enabled: true inside the TimeToLiveSpecification property to activate TTL on the ExpirationTime attribute.

AWS

Resources:
  LibraryBooks:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: LibraryBooks
      AttributeDefinitions:
        - AttributeName: BookID
          AttributeType: S
      KeySchema:
        - AttributeName: BookID
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
      TimeToLiveSpecification:
        AttributeName: ExpirationTime
# Enable TTL by setting Enabled to true here

Need a hint?

Set Enabled to true to turn on TTL for the attribute.

4

Complete the CloudFormation template

Add the ExpirationTime attribute to AttributeDefinitions with type Number to store the TTL timestamp.

AWS

Resources:
  LibraryBooks:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: LibraryBooks
      AttributeDefinitions:
        - AttributeName: BookID
          AttributeType: S
# Add ExpirationTime attribute definition with type Number here
      KeySchema:
        - AttributeName: BookID
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
      TimeToLiveSpecification:
        AttributeName: ExpirationTime
        Enabled: true

Need a hint?

TTL attribute must be defined as a Number type in AttributeDefinitions.