Putting a cap on the maximum number of parallel request in GenericParallel. Parallel calls are an extremely powerful tool and, like any powerful tool, can be dangerous. Hitting a backend service with 5 parallel requests will reduce the response time. Hitting the same service with 50 parallel requests may bring that service down, causing a prolonged downtime. Overload Protection To prevent accidental overloading, GenericParallel uses the concept of maximum concurrency.