Metrics not sent from an ASP.NET application with RC9

[devpro]

Bug Report

• Packages

  • OpenTelemetry.Exporter.OpenTelemetryProtocol 1.2.0-rc3
  • OpenTelemetry.Extensions.Hosting 1.0.0-rc9
  • OpenTelemetry.Instrumentation.AspNetCore 1.0.0-rc9

• Runtime: net6.0 (.NET SDK: 6.0.201)

Symptom

There is a regression in the latest packages ("RC9"), the metrics are not sent anymore by an ASP.NET application using AddOpenTelemetryMetrics extension method.

What is the expected behavior?

Metrics should be sent to the exporter defined in AddOpenTelemetryMetrics extension method.

For example, OpenTelemetry collector console should display messages like:

otel-collector    | 2022-03-23T10:10:57.968Z    INFO    loggingexporter/logging_exporter.go:54  MetricsExporter {"#metrics": 2}

What is the actual behavior?

No metrics is sent.

Reproduce

• Start an OpenTelemetry Collector listening on port 4317

#  docker-compose.yml
version: "3.9"
services:
  otel-collector:
    image: otel/opentelemetry-collector-contrib:latest
    container_name: otel-collector
    command: ["--config=/etc/otel-collector.yml"]
    volumes:
      - .opentelemetry-collector.yml:/etc/otel-collector.yml
    ports:
      - "4317:4317"

# opentelemetry-collector.yml
receivers:
  otlp:
    protocols:
      grpc:

exporters:
  logging:

service:
  pipelines:
    metrics:
      receivers: [otlp]
      exporters: [logging]

• Create a new ASP.NET REST API .NET6 project and add OpenTelemetry packages

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.2.0-rc3" />
    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol.Logs" Version="1.0.0-rc9" />
    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.0.0-rc9" />
    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.0.0-rc9" />
  </ItemGroup>

</Project>

• Update Progam.cs file

using System.Diagnostics;
using System.Diagnostics.Metrics;
using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetryMetrics(builder =>
{
    builder.SetResourceBuilder(ResourceBuilder.CreateDefault().AddService("MyService"));
    builder.AddAspNetCoreInstrumentation();
    builder.AddMeter("MyApplicationMetrics");
    builder.AddOtlpExporter(options => options.Endpoint = new Uri("http://localhost:4317"));
});

var app = builder.Build();

var activitySource = new ActivitySource("MyApplicationActivitySource");
var meter = new Meter("MyApplicationMetrics");
var requestCounter = meter.CreateCounter<int>("compute_requests");

app.MapGet("/", () =>
{
    requestCounter.Add(1);
    return Results.Ok();
});

app.Run();

• Run the web application and make a REST API call

# terminal #1
docker-compose up

# terminal #2
dotnet run --project <project_path>

# terminal #3
curl http://localhost:<port_numer>/

Additional Context

Same test is ok with previous versions:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.2.0-beta1" />
    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol.Logs" Version="1.0.0-rc8" />
    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.0.0-rc8" />
    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.0.0-rc8" />
  </ItemGroup>

</Project>

[cijothomas]

You are hit by this issue quite likely : #2991
use 1.0.0-rc10 (which is the newest version).

^ Ignore this.

[cijothomas]

You are hit by this issue quite likely : #2991 use 1.0.0-rc10 (which is the newest version).

Oops.. More like the issue is with PeriodicExporter. This should be addressed in the coming release.
https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md#unreleased - The 1st item from unreleased should address your issue.

Until then use the workaround from #2979 (comment)