Thundering herd problem
Encyclopedia
The thundering herd problem occurs when a large number of processes waiting for an event are awoken when that event occurs, but only one process is able to proceed at a time. After the processes wake 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 back to sleep, only to all wake up again to request access to the resource.
This occurs repeatedly, 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 is 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 (for example when programming with semaphores
).
Though the phrase is mostly used in computer science, it could be an abstraction of the observation seen when cattle
are released from a shed or when wildebeest
are crossing the Mara River
. In both instances, the movement is suboptimal.
This occurs repeatedly, 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 is 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 (for example when programming with semaphores
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type that provides a simple but useful abstraction for controlling access by multiple processes to a common resource in a parallel programming environment....
).
Though the phrase is mostly used in computer science, it could be an abstraction of the observation seen when cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
are released from a shed or when wildebeest
Wildebeest
The wildebeest , also called the gnu is an antelope of the genus Connochaetes. It is a hooved mammal...
are crossing the Mara River
Mara River
The Mara River is a river in Africa, flowing through Kenya and Tanzania, and lies across the migration path of ungulates in the Serengeti/Masai Mara game reserves....
. In both instances, the movement is suboptimal.