Each participant in the deadlock is holding a resource that the other needs. For example, imagine two transactions, T1 and T2. T1 has locked resource A, and T2 has locked resource B. T1 needs resource B to complete, but it can't get it until T2 releases the lock. Similarly, T2 needs resource A to complete, but it can't get it until T1 releases the lock. This creates a deadlock.
What makes a phantom deadlock different from a normal deadlock is that the participants aren't aware of each other. They're each just trying to do their own thing, but they're inadvertently blocking each other.
Phantom deadlocks are hard to detect because they're not caused by any single point of failure. They're caused by the distributed nature of the system itself. As a result, they can be very difficult to resolve.
One way to resolve phantom deadlocks is to increase the number of locks in the system. This makes it less likely that two transactions will need to lock the same resources at the same time. Another way to resolve phantom deadlocks is to use timeouts. If a transaction doesn't release a lock after a certain amount of time, it's aborted and the lock is released.
Phantom deadlocks are a rare occurrence, but they can be a serious problem when they do occur. By understanding what they are and how to resolve them, you can help to keep your distributed systems running smoothly.