There is indeed documentation about this. You can find it here: https://docs.mendix.com/refguide/clustered-mendix-runtime/#82-cluster-wide-locking-guaranteed-single-execution
But there is a module in the appstore you might find usefull if you need locking: Pessimistic locking https://marketplace.mendix.com/link/component/109405
You can also build it yourself like for instance when you have a task that can be done by multiple people. You can then make a claim functionality first so that the task is removed from all the other users tasklist.