TTL attribute setup in DynamoDB - Mini Project: Build & Apply

TTL Attribute Setup in DynamoDB

📖 Scenario: You are managing a DynamoDB table that stores user session data. To keep the table clean and efficient, you want to automatically delete expired sessions using DynamoDB's Time To Live (TTL) feature.

🎯 Goal: Set up the TTL attribute on the DynamoDB table to automatically remove expired session items.

📋 What You'll Learn

Create a DynamoDB table named UserSessions with a primary key SessionId (string).

Add an attribute called ExpirationTime to store the TTL timestamp.

Enable TTL on the UserSessions table using the ExpirationTime attribute.

💡 Why This Matters

🌍 Real World

Many applications store temporary data like user sessions or cache entries that should be automatically removed after some time to save storage and improve performance.

💼 Career

Understanding TTL setup in DynamoDB is important for backend developers and cloud engineers to manage data lifecycle and optimize database costs.

1

Create the DynamoDB table with primary key

Create a DynamoDB table named UserSessions with a primary key called SessionId of type string.

DynamoDB

# Create the DynamoDB table UserSessions with primary key SessionId
# Your code here

Need a hint?

Use the AWS CLI create-table command with --table-name UserSessions and define SessionId as the HASH key of type string.

2

Add the TTL attribute to the table items

Add an attribute called ExpirationTime to your session items. This attribute will store the expiration timestamp as a number (Unix epoch time).

DynamoDB

aws dynamodb create-table \
    --table-name UserSessions \
    --attribute-definitions AttributeName=SessionId,AttributeType=S \
    --key-schema AttributeName=SessionId,KeyType=HASH \
    --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5
# Add the ExpirationTime attribute to your session items when inserting
# Your code here

Need a hint?

Use put-item to add a session with ExpirationTime as a number representing the Unix timestamp.

3

Enable TTL on the table using the ExpirationTime attribute

Enable TTL on the UserSessions table by specifying the TTL attribute name as ExpirationTime using the AWS CLI.

DynamoDB

aws dynamodb create-table \
    --table-name UserSessions \
    --attribute-definitions AttributeName=SessionId,AttributeType=S \
    --key-schema AttributeName=SessionId,KeyType=HASH \
    --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

aws dynamodb put-item \
    --table-name UserSessions \
    --item '{"SessionId": {"S": "session123"}, "ExpirationTime": {"N": "1700000000"}}'
# Enable TTL on UserSessions table with attribute ExpirationTime
# Your code here

Need a hint?

Use the AWS CLI update-time-to-live command with Enabled=true and AttributeName=ExpirationTime.

4

Verify TTL configuration on the table

Verify that TTL is enabled on the UserSessions table and the TTL attribute is set to ExpirationTime using the AWS CLI.

DynamoDB

aws dynamodb create-table \
    --table-name UserSessions \
    --attribute-definitions AttributeName=SessionId,AttributeType=S \
    --key-schema AttributeName=SessionId,KeyType=HASH \
    --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

aws dynamodb put-item \
    --table-name UserSessions \
    --item '{"SessionId": {"S": "session123"}, "ExpirationTime": {"N": "1700000000"}}'

aws dynamodb update-time-to-live \
    --table-name UserSessions \
    --time-to-live-specification Enabled=true,AttributeName=ExpirationTime
# Verify TTL status on UserSessions table
# Your code here

Need a hint?

Use the AWS CLI describe-time-to-live command to check the TTL status on the table.