Overview

Adds capability of generating application metrics and exposing them via HTTP endpoint.

Installation

dotnet add package Convey.Metrics.AppMetrics

or just a dedicated package for Prometheus:

dotnet add package Convey.Metrics.Prometheus

Dependencies

• Convey

Options

• enabled - determines whether metrics endpoint is going to be available.
• influxEnabled - if true metrics will be reported to InfluxDB.
• prometheusEnabled - if true metrics will be formatted using Prometheus data model.
• prometheusFormatter - if set to protobuf then protobuf output formatter is going to be used. Otherwise, text output formatter is picked.
• InfluxUrl - connection string to InfluxDB instance e.g. http://localhost:8086. Required only if influxEnabled is true.
• database - InfluxDB database name. Required only if influxEnabled is true.
• interval - InfluxDB flush interval expressed in seconds. Required only if influxEnabled is true.

appsettings.json

"metrics": {
    "enabled": true,
    "influxEnabled": false,
    "prometheusEnabled": true,
    "influxUrl": "http://localhost:8086",
    "database": "pacco",
    "env": "local",
    "interval": 5
  }

or

"prometheus": {
  "enabled": true,
  "endpoint": "/metrics"
}

Usage

Inside Startup.cs extend IConveyBuilder with AddMetrics() and IApplicationBuilder with UseMetrics():

public IServiceProvider ConfigureServices(this IServiceCollection services)
{
    var builder = services.AddConvey()
        .AddMetrics();

    //other registrations    
    return builder.Build();
}

public void Configure(this IApplicationBuilder app)
{
    app.UseMetrics();
}

The above code registers all required services and exposes some default application metrics at two HTTP endpoints:

• http://host/metrics - depending on prometheusEnabled option, this endpoint exposes metrics that are either formatted using Prometheus data model or using standard, text formatter
• http://host/metrics-text - this endpoint exposes metrics that are always formated using standard, text formatter

Creating custom metrics

Once you finish Convey registration, you can create custom application metrics using the AppMetrics library for .NET Core. There are six different metrics types you can use:

• Gauges
• Counters
• Meters
• Histograms
• Timers
• Apdex

To create a custom metrics inject IMetricsRoot into selected class:

public class MetricsRegistry
{
    private readonly IMetricsRoot _metricsRoot;
    private readonly CounterOptions _findDiscountsQueries = new CounterOptions { Name = "find-discount" };

    public MetricsRegistry(IMetricsRoot metricsRoot)
        => _metricsRoot = metricsRoot;
    
    public void IncrementFindDiscountsQuery()
        => _metricsRoot.Measure.Counter.Increment(_findDiscountsQueries);
}