Maxmemory setting in Redis - Mini Project: Build & Apply

Configuring Redis Maxmemory Setting

📖 Scenario: You are managing a Redis database server that stores cached data for a web application. To prevent Redis from using too much memory and affecting other services on the server, you need to configure the maximum memory Redis can use.

🎯 Goal: Set up a Redis configuration to limit the maximum memory usage to 100 megabytes and verify the setting.

📋 What You'll Learn

Create a Redis configuration file with the maxmemory setting set to 100mb

Add a maxmemory-policy setting to specify how Redis should behave when maxmemory is reached

Use the Redis CLI to check the current maxmemory setting

Confirm the maxmemory-policy is correctly set in the configuration

💡 Why This Matters

🌍 Real World

Limiting Redis memory usage prevents it from consuming all server RAM, ensuring other applications run smoothly.

💼 Career

Configuring Redis memory settings is a common task for database administrators and backend developers managing caching layers.

1

Create Redis configuration file with maxmemory

Create a Redis configuration file named redis.conf and add the line maxmemory 100mb to set the maximum memory to 100 megabytes.

Redis

# Your code here
# Add the line 'maxmemory 100mb' to redis.conf

Need a hint?

The configuration file is a plain text file. Just add the line maxmemory 100mb.

2

Add maxmemory-policy to configuration

In the same redis.conf file, add the line maxmemory-policy allkeys-lru to specify that Redis should remove the least recently used keys when maxmemory is reached.

Redis

maxmemory 100mb
# Your code here
# Add the line 'maxmemory-policy allkeys-lru'

Need a hint?

The maxmemory-policy controls eviction behavior. Use allkeys-lru to evict least recently used keys from all keys.

3

Check maxmemory setting with Redis CLI

Use the Redis CLI command CONFIG GET maxmemory to check the current maxmemory setting on the running Redis server.

Redis

maxmemory 100mb
maxmemory-policy allkeys-lru
# Your code here
# Use 'CONFIG GET maxmemory' in Redis CLI

Need a hint?

Run redis-cli CONFIG GET maxmemory in your terminal connected to Redis.

4

Verify maxmemory-policy setting with Redis CLI

Use the Redis CLI command CONFIG GET maxmemory-policy to verify that the maxmemory-policy is set to allkeys-lru.

Redis

maxmemory 100mb
maxmemory-policy allkeys-lru
# CONFIG GET maxmemory
# Your code here
# Use 'CONFIG GET maxmemory-policy' in Redis CLI

Need a hint?

Run redis-cli CONFIG GET maxmemory-policy to confirm the eviction policy.