Dogpile effect is  referred as  the event when cache expires, and websites are hit by the multiple requests made by the client at the same time. It is also  referred to as cache stampede which occur when computing system employs cache which leads to the high load. One of the common way through which we can prevent dogpile effect is by implementing the semaphore locks in the cache. In this process  when the cache expires in the system, the first process  acquire the lock  and starts generating new value to the cache.