redis default port

2 min read 19-10-2024

Redis: Understanding the Default Port and Why It Matters

Redis, a popular in-memory data store, is known for its speed and versatility. But have you ever wondered why it runs on port 6379 by default? This article will delve into the world of Redis ports, exploring why 6379 is the standard and how it impacts your Redis deployments.

The "Default" Question: A Github Insight

On Github, a user asked: "Why is the default port for Redis 6379?" Here's a link to the discussion. The answer, provided by Salvatore Sanfilippo, the creator of Redis, is simple: "It's just a random number I chose."

While seemingly arbitrary, this choice has some underlying logic.

The "Random" Choice: Why 6379?

Avoiding Conflicts: Back in 2009 when Redis was born, the port landscape was less crowded. 6379 was a "random" number that was unlikely to be used by other services.
Memorability: While the number might seem strange, it's easy to remember compared to more complex ports.
The "Lucky" Factor: Some believe 6379 was chosen due to its connection to the number 6, which is often considered a lucky number in some cultures. While this is likely an urban legend, it adds a touch of whimsy to the story.

Why Default Ports Matter

While the default port choice might seem trivial, it's important for several reasons:

Security: Using the default port makes your Redis instance more vulnerable to attack, as attackers may know to target this port. It's crucial to change the default port for security reasons.
Conflicts: If you run multiple services on the same server, using the default port for both could lead to conflicts. You'll need to adjust ports to ensure they don't clash.
Deployment: If you're deploying Redis in a cloud environment, be aware of potential port restrictions or conflicting services that might use the default port.

Beyond the Default: How to Customize Ports

You can easily change the port Redis runs on during installation or by modifying configuration files.

1. During Installation:

Using redis-server: When starting Redis with the redis-server command, include the --port flag followed by your desired port number.
```
redis-server --port 6380
```
Using Docker: When running Redis in a Docker container, specify the desired port in the docker run command.
```
docker run -p 6381:6379 redis:latest
```

2. Configuration Files:

Modify the port parameter in your Redis configuration file (redis.conf).

Security Note: Changing the default port is essential for security, but it's not enough. Remember to implement strong authentication measures, firewalls, and other security best practices to protect your Redis instances.

Conclusion

While the default port 6379 for Redis was chosen for convenience and to avoid conflicts, it's crucial to customize this port for security and deployment reasons. By understanding the importance of port management, you can ensure your Redis instances are secure and function seamlessly within your environment.