--- layout: pattern title: Priority Queue Pattern folder: priority-queue permalink: /patterns/priority-queue/ categories: Behavioral tags: - Decoupling - Cloud distributed --- ## Intent Prioritize requests sent to services so that requests with a higher priority are received and processed more quickly than those of a lower priority. This pattern is useful in applications that offer different service level guarantees to individual clients. ## Explanation Applications may delegate specific tasks to other services; for example, to perform background processing or to integrate with other applications or services. In the cloud, a message queue is typically used to delegate tasks to background processing. In many cases the order in which requests are received by a service is not important. However, in some cases it may be necessary to prioritize specific requests. These requests should be processed earlier than others of a lower priority that may have been sent previously by the application. ## Class diagram  ## Applicability Use the Priority Queue pattern when * The system must handle multiple tasks that might have different priorities. * Different users or tenants should be served with different priority.. ## Credits * [Priority Queue pattern](https://docs.microsoft.com/en-us/azure/architecture/patterns/priority-queue)