Metrics

The Steeltoe metrics endpoint configures built-in instrumentation of various aspects of the application and exposes them in Spring Boot Metrics format.

The following instrumentation is automatically configured:

• CLR Metrics
  • Heap memory, Garbage collections, Thread utilization
• HTTP Client Metrics
  • Request timings & counts
• HTTP Server Metrics
  • Request timings & counts

All of these metrics are tagged with values specific to the requests being processed, thereby giving multi-dimensional views of the collected metrics.

Configure Settings

The following table describes the settings that you can apply to the endpoint:

Key	Description	Default
Id	The ID of the metrics endpoint.	metrics
Enabled	Whether to enable the metrics management endpoint.	true
IngressIgnorePattern	Regex pattern describing what incoming requests to ignore.	See MetricsOptions
EgressIgnorePattern	Regex pattern describing what outgoing requests to ignore.	See MetricsOptions

Each setting above must be prefixed with Management:Endpoints:Metrics.

To configure Observers, see Metric Observers

Enable HTTP Access

The default path to the metrics endpoint is computed by combining the global Path prefix setting together with the Id setting described in the preceding section. The default path is /actuator/metrics.

See the HTTP Access section to see the overall steps required to enable HTTP access to endpoints in an ASP.NET Core application.

To add the actuator to the service container and map its route, use the hostBuilder.AddMetricsActuator extension method from ManagementHostBuilderExtensions.

Alternatively, first, add the metrics actuator to the service container using the AddMetricsActuator() extension method from EndpointServiceCollectionExtensions.

Then add the metrics actuator middleware to the ASP.NET Core pipeline using the Map<MetricsEndpoint>() extension method from ActuatorRouteBuilderExtensions.

Add NuGet References

To use the metrics actuator, you need to add a reference to the Steeltoe.Management.EndpointCore NuGet package.

To add this type of NuGet to your project, add a PackageReference resembling the following:

<ItemGroup>
...
    <PackageReference Include="Steeltoe.Management.EndpointCore" Version="3.2.0"/>
...
</ItemGroup>

Alternatively, you can add the package through PowerShell:

PM>Install-Package  Steeltoe.Management.EndpointCore

ASP NET Core Example

The following example shows how to use the metrics actuator endpoint:

 public static IHost BuildHost(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .AddMetricsActuator()
            .Build();

Or:

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }
    public void ConfigureServices(IServiceCollection services)
    {
        // Add Metrics collection
        services.AddMetricsActuator(Configuration);

        ...
    }
    public void Configure(IApplicationBuilder app)
    {
         app.UseEndpoints(endpoints =>
            {
                // Add management endpoints into pipeline like this
                endpoints.Map<MetricsEndpoint>();

                // ... Other mappings
            });

    }
}