Why replication provides redundancy in Redis - See It in Action

Understanding Redundancy with Redis Replication

📖 Scenario: You are managing a small online store that uses Redis to store product inventory data. You want to make sure your data is safe even if one Redis server stops working.

🎯 Goal: Build a simple Redis setup with one master and one replica to see how replication creates redundancy and protects your data.

📋 What You'll Learn

Create a Redis master server configuration

Create a Redis replica server configuration that replicates the master

Add a key-value pair to the master

Verify the key exists on the replica to confirm redundancy

💡 Why This Matters

🌍 Real World

Many online services use Redis replication to keep data safe and available even if one server crashes.

💼 Career

Understanding replication and redundancy is important for roles like database administrator, backend developer, and system engineer.

1

Set up Redis master server configuration

Create a Redis configuration file named redis-master.conf with the default settings and specify the port as 6379.

Redis

# Create redis-master.conf with port 6379
# Your code here

Need a hint?

The master server listens on port 6379 by default. Just specify port 6379 in the config file.

2

Set up Redis replica server configuration

Create a Redis configuration file named redis-replica.conf that sets the port to 6380 and configures it to replicate the master at 127.0.0.1 on port 6379 using the replicaof directive.

Redis

port 6379
# Default Redis master configuration

# Create redis-replica.conf with port 6380 and replicaof 127.0.0.1 6379
# Your code here

Need a hint?

Use replicaof 127.0.0.1 6379 to tell the replica where the master is.

3

Add data to the master server

Connect to the Redis master server on port 6379 and add a key called product:1001 with the value "In Stock" using the SET command.

Redis

port 6379
# Default Redis master configuration

port 6380
replicaof 127.0.0.1 6379

# Connect to master and add key product:1001 with value "In Stock"
# Your code here

Need a hint?

Use the Redis command SET product:1001 "In Stock" on the master server.

4

Verify data replication on the replica server

Connect to the Redis replica server on port 6380 and use the GET command to check that the key product:1001 has the value "In Stock", confirming replication and redundancy.

Redis

port 6379
# Default Redis master configuration

port 6380
replicaof 127.0.0.1 6379

# Connect to master and add key product:1001 with value "In Stock"
SET product:1001 "In Stock"

# Connect to replica and verify key product:1001 has value "In Stock"
# Your code here

Need a hint?

Use GET product:1001 on the replica server to confirm the value.