Getting All Connected Clients in Redis Using PHP (Detailed Guide w/ Code Examples)

Use Case(s)

One common use case is during debugging or monitoring of an application where you might need to know how many clients are currently connected to your Redis server. This can help troubleshoot issues with connection limits or provide insights into application usage patterns.

Code Examples

To retrieve a list of all connected client information, we can use the CLIENT LIST command in Redis:

$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
$clientList = $redis->rawCommand('CLIENT', 'LIST');
print_r($clientList);

In this example, rawCommand() is used to send a direct command to Redis server. 'CLIENT LIST' returns a list of all connected clients and their respective details.

Please note that this command should be used with caution as it may affect performance on busy servers, due to the volume of data it could potentially return.

Best Practices

• Always close connections when they're no longer needed to conserve system resources.
• Limit the use of commands that can potentially return large amounts of data, such as CLIENT LIST, to avoid affecting server performance.

Common Mistakes

• Not checking for successful connection before sending commands to Redis server.
• Over-relying on CLIENT LIST for routine operations - remember, it can impact server performance.

FAQs

Q: Can I limit the amount of data returned by the 'CLIENT LIST' command?

A: No, 'CLIENT LIST' will return data for all clients. If it's causing performance issues, consider sampling at regular intervals instead of continuously monitoring.