Azure Durable Function

Aggregator (scatter-gather) implementation with Azure Durable Functions.

Requirements:

• Azure Functions Core Tools SDK
• Azure Azurite
• Service Bus namespace
• Node 16+

Setup

Ramp up a Service Bus instance:

# Create the thing
az group create -n "rg-local-dev" -l "eastus2"
az servicebus namespace create -n "bus-az-durable-functions-dev" -g "rg-local-dev" -l "eastus2" --sku "Basic"
az servicebus queue create -n "inbound-queue" --namespace-name "bus-az-durable-functions-dev" -g "rg-local-dev" --enable-partitioning
az servicebus queue create -n "outbound-queue" --namespace-name "bus-az-durable-functions-dev" -g "rg-local-dev" --enable-partitioning

# Export for the function
export AZURE_SERVICEBUS_CONNECTION_STRING=$(az servicebus namespace authorization-rule keys list -g "rg-local-dev" --namespace-name "bus-az-durable-functions-dev" --name "RootManageSharedAccessKey" --query "primaryConnectionString" -o tsv)

💡 To quick start Service Bus local testing use my Postman collection boilerplate

Start Azurite:

azurite -s -l /tmp/azurite

Create local.settings.json with the following content:

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "node",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "QueueConnectionString": "AccountName=devstoreaccount1;AccountKey=<<<ACCOUNT_KEY>>>;DefaultEndpointsProtocol=http;BlobEndpoint=http://127.0.0.1:10000/devstoreaccount1;QueueEndpoint=http://127.0.0.1:10001/devstoreaccount1;TableEndpoint=http://127.0.0.1:10002/devstoreaccount1;"
  }
}

Replace the account key with your emulator key (use Storage Explorer to the Key).

Start the function app:

func start

Testing the app by sending messages to the queue.

Reference

• Durable Functions .NET Entities
• Aggregator (Scatter-Gather)
• Stateful Entities
• Fan-out/fan-in scenario in Durable Functions
• Singleton orchestrators in Durable Functions
• Functions built-in hooks