The new 3.2 release of Symfony improve the integration of the framework in containers (cache, dynamic env vars, etc...).
With such containers, it's easier to scale our services no matter the physical machine where the service ends up. But this bring a new issue: sometimes services need to lock some things, and actually, the framework only expose a "local" filesystem lock (which is good and efficient for a local usage).

At first I just wanted to create a PR to add a new RedisLockHandler (which implement the redlock strategy). But I wonder where to put the code. IMO, it doesn't make sens to add such feature in the filesystem component.

That's the subject of this issue:

• Do we need such feature in Symfony.
• Where should it be located (new component?)

If a new component is created, then, other lock could be implemented:

• filesystem
• semaphore
• memcached
• redis
• pdo

Such cross-network locks could solve issues like #4976