Redis is a popular in-memory data store commonly used for caching and session storage — this guide covers installation and basic configuration specifically on AlmaLinux/Rocky Linux.
Step 1 — Install Redis
sudo dnf install redis -yAvailable directly from the base AppStream repository on current AlmaLinux/Rocky Linux versions, no additional repository needed.
Step 2 — Start and Enable Redis
sudo systemctl enable --now redisStep 3 — Verify Redis Is Running
redis-cli pingShould respond with PONG.
Step 4 — Configure Redis (Basic Security Hardening)
sudo nano /etc/redis/redis.confbind 127.0.0.1
requirepass CHANGE_ME_STRONG_PASSWORDBy default, Redis has no authentication — if any application/network path could reach it, setting a password is essential; binding to localhost only is the safest default unless genuinely needed otherwise.
Step 5 — Restart Redis to Apply Configuration
sudo systemctl restart redisStep 6 — Testing Authenticated Access
redis-cli -a CHANGE_ME_STRONG_PASSWORD pingConfiguring firewalld (If Remote Access Is Genuinely Needed)
sudo firewall-cmd --permanent --add-port=6379/tcp --zone=internal
sudo firewall-cmd --reloadOnly necessary if Redis genuinely needs to be reachable from another server — for a local application on the same VPS, localhost binding alone (without any firewall opening) is both simpler and more secure.
SELinux Considerations
See Understanding SELinux Basics on AlmaLinux/Rocky Linux — the standard Redis package installation typically works correctly with default SELinux policy; if you relocate data directories or change default ports, verify SELinux context/policy accommodates the change.
Configuring Persistence
save 900 1
save 300 10
save 60 10000Controls how frequently Redis saves its in-memory dataset to disk — adjust based on your durability needs versus performance trade-offs (more frequent saves add some overhead).
Setting a Memory Limit
maxmemory 512mb
maxmemory-policy allkeys-lruPrevents Redis from consuming unbounded memory; the eviction policy determines what happens when the limit is reached (LRU eviction is a common, reasonable default for cache use cases).
Connecting from an Application
npm install redisconst redis = require('redis');
const client = redis.createClient({ password: 'CHANGE_ME_STRONG_PASSWORD' });Monitoring Redis
redis-cli infoProvides detailed statistics on memory usage, connected clients, and operation counts — useful for basic health checking and troubleshooting.
Common Errors
"NOAUTH Authentication required" errors — confirms your password protection is actually working as configured; ensure your application's connection configuration includes the correct password.
Continue Reading
- How to Configure firewalld on AlmaLinux/Rocky Linux
- How to Add Caching to Speed Up a Slow Web Application
- Understanding SELinux Basics on AlmaLinux/Rocky Linux
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