Retry output Service Bus Message on failure in Azure Functions

I have an HTTP Trigger Azure Function. This function will persist some data into the database, return HttpResponseData and output an Azure Service Bus message.

The case is, if the function can't send the message to Service Bus by any reason (misconfigured service bus connection string, for example), the data is already persisted but there is no message in service bus.

How do I make Azure Functions to retry on failing to send a message to Service Bus or roll back the entire transaction?

This is my function code, .NET 6 Isolated.

[Function("TestFunction")]
public async Task<TestFunctionResult> Run([HttpTrigger(AuthorizationLevel.Function, "get")] HttpRequestData req)
{
    _logger.LogInformation("C# HTTP trigger function processed a request.");

    // This is to persist some data to the database
    var result = await _someService.SubmitSomeData(someData);

    // This is to create an HttpResponseData object
    var response = await req.CreateResponseAsync(result);

    return new TestFunctionResult
    {
        OutputMessage = new TestTopic("First Last", "My Company"),
        HttpResponse = response
    };
}

This is the definition of TestFunctionResult

public class TestFunctionResult
{
    [ServiceBusOutput("TestTopic", Connection = "ServiceBus", EntityType = ServiceBusEntityType.Topic)]
    public TestTopic OutputMessage { get; set; }

    public HttpResponseData HttpResponse { get; set; }
}

I have used your code to reproduce the issue and it worked for me.

To retry on failing to send a message to Service Bus, I have added the below code in host.json file as per documentation

host.json file-

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      }
    }
  },
  "extensions": {
    "serviceBus": {
      "clientRetryOptions": {
        "mode": "exponential",
        "tryTimeout": "00:01:00",
        "delay": "00:00:00.80",
        "maxDelay": "00:01:00",
        "maxRetries": 3
      }
    }
  }
}

function.cs file-

using System;
using System.Net;
using System.Text;
using Azure.Messaging.ServiceBus;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker.Extensions.ServiceBus;
    
namespace FunctionApp2
{
    public class TestTopic
    {
        public string Name { get; set; }
        public string Company { get; set; }

        public TestTopic(string name, string company)
        {
            Name = name;
            Company = company;
        }
    }

    public static class Function1
    {
        [Function("TestFunction")]
        public static async Task<TestFunctionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get")] HttpRequestData reqs, FunctionContext executionContext)
        {

            var logger = executionContext.GetLogger("TestFunction");

            // This is to create an HttpResponseData object
            var response = reqs.CreateResponse(HttpStatusCode.OK);

            return new TestFunctionResult
            {
                OutputMessage = new TestTopic("First Last", "My Company"),
                HttpResponse = response
            };
        }
    }

    public class TestFunctionResult
    {
        [ServiceBusOutput("TestTopic", Connection = "ServiceBusConnection", EntityType = ServiceBusEntityType.Topic)]
        public TestTopic? OutputMessage { get; set; }
        public HttpResponseData? HttpResponse { get; set; }
    }
}

local.settings.json file-

{
    "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
    "ServiceBusConnection": "your connection string"
  }
}

Output-

Portal-
Before-

After-