open-telemetry / opentelemetry-dotnet

Monitoring and Logging for OpenTelemetry .NET

Understanding how to set up and maintain monitoring and logging in OpenTelemetry .NET, including configuration, logging mechanisms, and alerting.

What is Monitoring and Logging?

Monitoring and logging are essential practices for observability and maintaining the health and performance of applications. OpenTelemetry .NET is a popular observability framework that provides monitoring and logging capabilities for .NET applications.

Why is Monitoring and Logging important?

Monitoring and logging help developers and operations teams gain insights into application performance, identify and troubleshoot issues, and ensure the health and reliability of their systems. With OpenTelemetry .NET, developers can easily instrument their applications to collect and send telemetry data to various backends for further analysis and visualization.

What is Monitoring and Logging in OpenTelemetry .NET?

OpenTelemetry .NET provides several options for monitoring and logging, including:

  1. Built-in logging: OpenTelemetry .NET includes built-in support for popular logging frameworks like Serilog, NLog, and Microsoft.Extensions.Logging. This allows developers to use their preferred logging framework while also sending logs as telemetry data to various backends.

  2. Tracing: OpenTelemetry .NET supports distributed tracing, which helps developers understand the flow of requests and responses between services. This can be particularly useful in microservices architectures and complex systems.

  3. Metrics: OpenTelemetry .NET allows developers to instrument their applications to collect and send metrics data, which can be used to monitor application performance and identify bottlenecks.

  4. Log collection and forwarding: OpenTelemetry .NET includes built-in support for collecting and forwarding logs to various backends, such as Elasticsearch, Splunk, and others.

Configuration

OpenTelemetry .NET can be configured using various methods, including:

  1. Code-based configuration: Developers can configure OpenTelemetry .NET directly in their code using the AddOpenTelemetry method.

  2. Appsettings.json or appsettings.yml: OpenTelemetry .NET supports configuration from appsettings.json or appsettings.yml files.

  3. Environment variables: OpenTelemetry .NET also supports configuration using environment variables.

Logging Mechanisms

OpenTelemetry .NET supports several logging mechanisms, including:

  1. Console logging: Developers can use console logging to see logs in real-time as their application runs.

  2. File logging: OpenTelemetry .NET supports logging to files, which can be useful for long-term retention and analysis.

  3. Remote logging: OpenTelemetry .NET supports sending logs to remote backends for centralized management and analysis.

Alerting

OpenTelemetry .NET includes support for alerting, which can be used to proactively identify and respond to issues. Alerts can be configured based on various conditions, such as metric thresholds or log patterns.

Examples

Here are some examples of using OpenTelemetry .NET for monitoring and logging:

Tracing

using OpenTelemetry;
          using OpenTelemetry.Api;
          using OpenTelemetry.Api.Tracing;
          using OpenTelemetry.Exporter. Jaeger;
          using OpenTelemetry.Instrumentation.AspNetCore;
          using Microsoft.AspNetCore.Builder;
          using Microsoft.AspNetCore.Hosting;
          
          public class Startup
          {
              public void ConfigureServices(IServiceCollection services)
              {
                  services.AddOpenTelemetryTracing(o =>
                  {
                      o.AddJaegerExporter(exporterOptions =>
                      {
                          exporterOptions.AgentHost = new Uri("http://localhost:14268");
                      });
                      o.AddAspNetCoreInstrumentation();
                  });
          
                  services.AddControllers();
              }
          
              public void Configure(IApplicationBuilder app, IWebJobsStartup startups)
              {
                  if (app.Environment.IsDevelopment())
                  {
                      app.UseDeveloperExceptionPage();
                  }
          
                  app.UseRouting();
          
                  app.UseEndpoints(endpoints =>
                  {
                      endpoints.MapControllers();
                  });
          
                  app.UseOpenTelemetry();
              }
          }

Metrics

using OpenTelemetry;
          using OpenTelemetry.Api;
          using OpenTelemetry.Api.Metrics;
          using OpenTelemetry.Instrumentation.AspNetCore;
          using Microsoft.AspNetCore.Builder;
          using Microsoft.AspNetCore.Hosting;
          
          public class Startup
          {
              public void ConfigureServices(IServiceCollection services)
              {
                  services.AddOpenTelemetryMetrics();
                  services.AddOpenTelemetryTracing();
                  services.AddOpenTelemetryInstrumentation();
                  services.AddControllers();
              }
          
              public void Configure(IApplicationBuilder app, IWebJobsStartup startups)
              {
                  if (app.Environment.IsDevelopment())
                  {
                      app.UseDeveloperExceptionPage();
                  }
          
                  app.UseRouting();
          
                  app.UseEndpoints(endpoints =>
                  {
                      endpoints.MapControllers();
                  });
          
                  app.UseOpenTelemetry();
              }
          }

Logging

using OpenTelemetry;
          using OpenTelemetry.Api;
          using OpenTelemetry.Api.Logging;
          using OpenTelemetry.Exporter.Console;
          using Microsoft.Extensions.Logging;
          using Microsoft.Extensions.Logging.Console;
          
          public class Program
          {
              public static void Main(string[] args)
              {
                  LoggingBuilder loggingBuilder = LoggingBuilder.CreateConsoleBuilder(args);
                  loggingBuilder.AddOpenTelemetry();
                  ILoggerFactory loggerFactory = loggingBuilder.Build();
                  ILogger<Program> logger = loggerFactory.CreateLogger<Program>();
          
                  logger.LogInformation("Starting application.");
          
                  try
                  {
                      // Application code here.
                  }
                  catch (Exception ex)
                  {
                      logger.LogError(ex, "An error occurred.");
                  }
          
                  logger.LogInformation("Application finished.");
              }
          }

References


          Sources:
          - OpenTelemetry .NET Documentation: <https://opentelemetry.io/docs/instrumentations/net/>
          - OpenTelemetry .NET GitHub Repository: <https://github.com/open-telemetry/opentelemetry-dotnet>
          - OpenTelemetry .NET Tracing: <https://opentelemetry.io/docs/instrumentations/net/tracing/>
          - OpenTelemetry .NET Metrics: <https://opentelemetry.io/docs/instrumentations/net/metrics/>
          - OpenTelemetry .NET Logging: <https://opentelemetry.io/docs/instrumentations/net/logging/>