Thundering Herd Problem --- From Wiki

The thundering herd problem occurs when a large number of processes waiting for an event are woken when

that event occurs, but only one process can proceed at a time. After the processes woke up, they all demand the

resource and a decision must be made as to which process can continue. After the decision is made, the remaining

processes are put pack to sleep, only to all wake up again to request access to the resource.

This occurs repeatly, until there are no more processes to be woken up. Because all the processes use system

resources upon waking, it is more efficient if only one process was woken up at a time. This may render the computer

unusable, but it can also be used as a technique if there is no other way to decide which process should continue.