Distributed lock.

also: distributed locks · distributed locking · Redlock

A lock that holds across machines, usually from a coordination service, so only one process at a time does a piece of work.

the two-minute refresher

Acquire with a timeout or lease so a crashed holder can't block forever.
Pauses and partitions mean two holders can briefly overlap.
So the protected resource must check a fencing token.
For efficiency (avoid duplicate work) a simple lock is fine; for correctness, fence it.

also: distributed locks · distributed locking · Redlock

A lock that holds across machines, usually from a coordination service, so only one process at a time does a piece of work.

Acquire with a timeout or lease so a crashed holder can't block forever.
Pauses and partitions mean two holders can briefly overlap.
So the protected resource must check a fencing token.
For efficiency (avoid duplicate work) a simple lock is fine; for correctness, fence it.