如何配置 singleton - 队列触发 Azure Function

Question

I'd like an azure function that's triggered from an Azure storage account queue to run as a singleton.

The function app is in-process and net6:

    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>

My function currently looks as follows:

[FunctionName(nameof(QueueTrigger))]    
public async Task QueueBatch([QueueTrigger("TriggerSurvey")] TriggerMsg triggerMsg)

Anyone know how to configure so that only one instance of the function will ever poll the queue?

Answer 1

The batch size and the threshold for getting a new batch are configurable in the host.json file. If you want to minimize parallel execution for queue-triggered functions in a function app, you can set the batch size to 1. This setting eliminates concurrency only so long as your function app runs on a single virtual machine (VM).

host.json > extensions > queues > batchSize

https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-queue-trigger?tabs=csharp