Unable to subscribe to Redis global key expiration events due to Laravel prefix handling

[Lukasss93]

Laravel Version

12.30.1

PHP Version

8.4.2

Database Driver & Version

Redis 8.0.1

Description

I have a use case where I need to subscribe to a Redis event when a key expires, in order to trigger specific logic.

After enabling keyspace notifications in Redis with:

# redis-cli >
CONFIG SET notify-keyspace-events Ex

and subscribing with:

Redis::subscribe(['__keyevent@0__:expired'], function ($message) {
    // handle logic
});

I don’t receive the global event.

This happens because Laravel only listens to channels with the prefix defined in config/database.php under redis.options.prefix.
If I replace the default prefix with an empty string, the subscription works correctly.

It looks like currently there is no way to listen to global Redis events without modifying the prefix.

Question

Is it possible to implement a way to subscribe to global events without having to remove/override the Redis prefix?
And also without having to set an empty prefix at runtime, since I might want to subscribe to both Redis global events and other prefixed channels at the same time.

This seems related to this issue: #29449

Steps To Reproduce

1. Enable Redis key expiration notifications:

   CONFIG SET notify-keyspace-events Ex

2. Use Laravel to subscribe to the expiration channel:

   Redis::subscribe(['__keyevent@0__:expired'], function ($message) {
       // handle logic
   });

3. Let a key expire.

4. Notice that no event is received unless you remove the prefix by setting redis.options.prefix to an empty string in config/database.php.

[github-actions]

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[eaaqaawaa]

I believe there's no way to subscribe to global events without removing or overriding the Redis prefix, as it's controlled by Redis. You could create a separate Redis connection configuration specifically for global events.

[Lukasss93]

One possible solution would be to tell Laravel not to apply the prefix when subscribing to channels that start with __keyspace or __keyevent.

Reference: https://redis.io/docs/latest/develop/pubsub/keyspace-notifications/

[somarkn99]

There’s no way to subscribe to Redis global keyspace/keyevent channels if a connection-level prefix is applied, because the client prefixes every channel name.

Workable approach today: define a second Redis connection with an empty options.prefix and use that connection only for __keyevent / __keyspace subscriptions:

Redis::connection('events')->psubscribe(['__keyevent@0__:*'], function ($channel, $message) {
    // ...
});

Potential improvement for Laravel: allow opting out of prefixing for specific channels/patterns (e.g. __keyevent / __keyspace) via a config option like:

'options' => [
  'prefix' => 'laravel:',
  'skip_prefix_for_channels' => [
    '/^__keyevent@\d+__:/',
    '/^__keyspace@\d+__:/',
  ],
],

I can open a PR for this if maintainers think this is a good fit.