Note: for information on bootstrapping OpenTelemetry or Application Insights SDK please refer to the documentation: .

Logging

Logging was redesigned in .NET Core, bringing an integrated and extensible API. allow the collection of logs in multiple formats and targets. When deciding a logging platform, consider the following features:

• Centralized: allowing the collection/storage of all system logs in a central location.


• Structured logging: allows you to add searchable metadata to logs.


• Searchable: allows searching by multiple criteria (app version, date, category, level, text, metadata, etc.)


• Configurable: allows changing verbosity without code changes (based on log level and/or scope).


• Integrated: integrated into tracing, facilitating analysis of traces and logs in the same tool.

The sample application uses the ILogger interface for logging. The snippet below demonstrates an example of structure logging. Which captures events using was announced, promising to standardize telemetry instrumentation and collection across languages and tools. Before OpenTelemetry (or its predecessors OpenCensus and OpenTracing), adding observability would often mean adding proprietary SDKs (in)directly to the code base.

The OpenTelemetry .NET SDK is currently in alpha. The Azure Monitor Application Insights team is investing in OpenTelemetry as a next step of Azure Monitor SDKs evolution.

Quick Intro on Tracing with OpenTelemetry

In a nutshell, instance.

In the asynchronous distributed transaction scenario, track the following operations:

HTTP Requests between microservices

HTTP correlation propagation is part of both SDKs. With the only requirement of setting activity id format to .

Creating an Operation Trace

The snippet below demonstrates how the publish operation trace can be created. It adds the trace information to the enqueued message header, which will later be used to link both operations.

Activity activity = null;

if (diagnosticSource.IsEnabled("Sample.RabbitMQ"))

{

    // Generates the Publishing to RabbitMQ trace

    // Only generated if there is an actual listener

    activity = new Activity("Publish to RabbitMQ");  

    diagnosticSource.StartActivity(activity, null);

}



// Add current activity identifier to the RabbitMQ message

basicProperties.Headers.Add("traceparent", Activity.Current.Id);



channel.BasicPublish(...)



if (activity != null)

{

     // Signal the end of the activity

     diagnosticSource.StopActivity(activity, null);

}

A collector, which subscribes to target activities, is required to publish the trace to a backend. Implementing a collector is not a straightforward task and is intended to be used by SDK implementors. The snippet below is taken from the sample application, where a simplified and not production-ready, RabbitMQ collector for OpenTelemetry was implemented:

public class RabbitMQListener : ListenerHandler

{

    public override void OnStartActivity(Activity activity, object payload)

    {

            var span = this.Tracer.StartSpanFromActivity(activity.OperationName, activity);

            foreach (var kv in activity.Tags)

                span.SetAttribute(kv.Key, kv.Value);

    }



    public override void OnStopActivity(Activity activity, object payload)

    {

        var span = this.Tracer.CurrentSpan;

        span.End();

        if (span is IDisposable disposableSpan)

        {

            disposableSpan.Dispose();

        }

    }

}



var subscriber = new DiagnosticSourceSubscriber(new RabbitMQListener("Sample.RabbitMQ", tracer), DefaultFilter);

subscriber.Subscribe();

For more information on how to build collectors, please refer to OpenTelemetry/Application Insights built-in collectors as well as this exporter. Prometheus combined with .

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