PERSIST to remove expiry in Redis - Mini Project: Build & Apply

Using PERSIST to Remove Expiry from Redis Keys

📖 Scenario: You are managing a Redis database that stores temporary session data for users. Sometimes, you want to keep a session permanently by removing its expiry time.

🎯 Goal: Learn how to create a Redis key with an expiry time and then remove that expiry using the PERSIST command.

📋 What You'll Learn

Create a Redis key named session:user123 with the value active and set it to expire in 60 seconds.

Create a variable to hold the key name key_name with the value session:user123.

Use the PERSIST command on the key stored in key_name to remove its expiry.

Verify that the key no longer has an expiry time.

💡 Why This Matters

🌍 Real World

Managing user sessions or temporary data in Redis often requires setting expiry times and sometimes removing them to keep data permanently.

💼 Career

Understanding how to control key expiry in Redis is important for backend developers and system administrators working with caching and session management.

1

Create a Redis key with expiry

Create a Redis key named session:user123 with the value active and set it to expire in 60 seconds using the SET command with the EX option.

Redis

# Create the key with expiry
# Your code here

Need a hint?

Use SET key value EX seconds to set a key with expiry.

2

Create a variable for the key name

Create a variable called key_name and set it to the string session:user123.

Redis

SET session:user123 active EX 60
# Create variable key_name
# Your code here

Need a hint?

Assign the string 'session:user123' to key_name.

3

Remove expiry using PERSIST

Use the PERSIST command on the key stored in the variable key_name to remove its expiry time.

Redis

SET session:user123 active EX 60
key_name = 'session:user123'
# Remove expiry from the key
# Your code here

Need a hint?

Use PERSIST key to remove expiry from a key.

4

Verify the key has no expiry

Use the TTL command on the key stored in key_name to check that it no longer has an expiry time.

Redis

SET session:user123 active EX 60
key_name = 'session:user123'
PERSIST session:user123
# Check TTL of the key
# Your code here

Need a hint?

Use TTL key to check the remaining time to live of a key. It returns -1 if the key has no expiry.