30 lines
1.8 KiB
Markdown
30 lines
1.8 KiB
Markdown
---
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layout: pattern
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title: Priority Queue Pattern
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folder: priority-queue
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permalink: /patterns/priority-queue/
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categories: Behavioral
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tags:
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- Decoupling
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---
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## Intent
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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.
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## Explanation
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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.
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## Class diagram
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## Applicability
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Use the Property pattern when
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* The system must handle multiple tasks that might have different priorities.
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* Different users or tenants should be served with different priority..
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## Real world examples
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* [ Priority Queue Pattern](https://docs.microsoft.com/en-us/previous-versions/msp-n-p/dn589794(v=pandp.10))
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Microsoft Azure does not provide a queuing mechanism that natively support automatic prioritization of messages through sorting. However, it does provide Azure Service Bus topics and subscriptions, which support a queuing mechanism that provides message filtering, together with a wide range of flexible capabilities that make it ideal for use in almost all priority queue implementations.
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