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Priority Queue Pattern
Priority Queue Pattern
- thierry sinassamy
Owned by thierry sinassamy
Problem
To handle tasks efficiently based on their priority, workloads need a mechanism to prioritize and execute tasks accordingly.
Workloads process tasks in the order they arrive, using a first-in, first-out (FIFO) queue structure.
Solution
Application sending a message to the queue assigns a priority to the message, and consumers process the messages by priority.
There are 2 approaches :
Single queue : All messages are sent to one queue and each message assigned a priority → application (producer) assigns a priority to each message and sends the message to the queue.
Multiple queue : Separate queues are used for each message priority.
Single Queue : Diagram from Microsoft Documentation
Priority Queue In Practice
Example of code in C# : sending message as Priority Low and High
using System;
using System.Threading.Tasks;
using Azure.Messaging.ServiceBus;
using Microsoft.Azure.WebJobs;
namespace PriorityQueueSender
{
public static class PriorityQueueSenderFn
{
[FunctionName("PriorityQueueSenderFunction")]
public static async Task Run(
[TimerTrigger("0,30 * * * * *")] TimerInfo myTimer,
[ServiceBus("messages", Connection = "ServiceBusConnection")] IAsyncCollector<ServiceBusMessage> collector )
{
for (int i = 0; i < 10; i++)
{
var messageId = Guid.NewGuid().ToString();
var lpMessage = new ServiceBusMessage() { MessageId = messageId };
lpMessage.ApplicationProperties["Priority"] = Priority.Low;
lpMessage.Body = BinaryData.FromString($"Low priority message with Id: {messageId}");
await collector.AddAsync(lpMessage);
messageId = Guid.NewGuid().ToString();
var hpMessage = new ServiceBusMessage() { MessageId = messageId };
hpMessage.ApplicationProperties["Priority"] = Priority.High;
hpMessage.Body = BinaryData.FromString($"High priority message with Id: {messageId}");
await collector.AddAsync(hpMessage);
}
}
}
}, multiple selections available,