Error: redis-server failed to start advanced key-value store

Resolving "redis-server failed to start advanced key-value store" Error

This error occurs when the Redis server fails to initialize. Here are specific steps to diagnose and resolve the issue:

1. Check Redis Service Status

First, verify the Redis service status:

sudo systemctl status redis-server

Look for error messages in the output.

2. Examine Redis Logs

Check Redis logs for detailed error information:

sudo tail -n 50 /var/log/redis/redis-server.log

3. Verify Redis Configuration

Ensure the Redis configuration file is correct:

sudo redis-server /etc/redis/redis.conf --test-memory 1

This command validates the configuration and checks available memory.

4. Check Port Availability

Verify if the default Redis port (6379) is available:

sudo lsof -i :6379

If the port is in use, modify it in /etc/redis/redis.conf:

sudo nano /etc/redis/redis.conf

Change the port directive to an available port number.

5. Ensure Correct Permissions

Set proper permissions for Redis directories:

sudo chown -R redis:redis /var/lib/redis
sudo chmod 750 /var/lib/redis

6. Check System Resources

Verify available system resources:

free -m
df -h
top

Ensure sufficient memory and disk space are available.

7. Disable Transparent Huge Pages (THP)

THP can cause issues with Redis. Disable it:

echo never > /sys/kernel/mm/transparent_hugepage/enabled

Add this to /etc/rc.local for persistence across reboots.

8. Adjust System Limits

Increase system limits for Redis:

sudo nano /etc/security/limits.conf

Add these lines:

redis soft nofile 65536
redis hard nofile 65536

9. Reinstall Redis

If issues persist, try reinstalling Redis:

sudo apt remove redis-server
sudo apt autoremove
sudo apt update
sudo apt install redis-server

10. Enable Overcommit Memory

Allow Redis to use more memory:

sudo sysctl vm.overcommit_memory=1

Make it persistent by adding to /etc/sysctl.conf:

echo "vm.overcommit_memory = 1" | sudo tee -a /etc/sysctl.conf

11. Check for Conflicting Services

Ensure no other services are using Redis resources:

sudo netstat -tulpn | grep LISTEN

12. Verify Redis Binary

Ensure the Redis binary is executable:

sudo chmod +x /usr/bin/redis-server

After applying these changes, restart Redis:

sudo systemctl restart redis-server

If the error persists, collect all relevant logs and configuration files, and consider seeking help from the Redis community forums or professional support.