Correlation

CorrelationInfo provides a common set of correlation levels:

• Transaction Id - ID that relates different requests together into a functional transaction.
• Operation Id - Unique ID information for a single request.
• Operation parent Id - ID of the original service that initiated the request.

Installation

This feature requires to install our NuGet package

PM > Install-Package Arcus.Observability.Correlation

What We Provide

The Arcus.Observability.Correlation library provides a way to get access to correlation information across your application. What it DOES NOT provide is how this correlation information is initially set.

It uses the Microsoft dependency injection mechanism to register an ICorrelationInfoAccessor and ICorrelationInfoAccessor<> implementation that is available.

Example

using Arcus.Observability.Correlation;

namespace Application
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            // Adds operation and transaction correlation to the application,
            // using the `DefaultCorrelationInfoAccessor` as `ICorrelationInfoAccessor` that stores the `CorrelationInfo` model internally.
            services.AddCorrelation();
        }
    }
}

Custom Correlation

We register two interfaces during the registration of the correlation: ICorrelationInfoAccessor and ICorrelationInfoAccessor<>. The reason is because some applications require a custom CorrelationInfo model, and with using the generic interface ICorrelationInfoAccessor<> we can support this.

Example

using Microsoft.Extensions.DependencyInjection;
using Arcus.Observability.Correlation;

namespace Application
{
    public class OrderCorrelationInfo : CorrelationInfo
    {
        public string OrderId { get; }
    }

    public class Startup
    {
        public void ConfigureService(IServiceCollection services)
        {
            services.AddCorrelation<OrderCorrelationInfo>();
        }
    }
}

Accessing Correlation Throughout the Application

When a part of the application needs access to the correlation information, you can inject one of the two interfaces:

using Arcus.Observability.Correlation;

namespace Application
{
    public class OrderService
    {
        public OrderService(ICorrelationInfoAccessor accessor)
        {
             CorrelationInfo correlationInfo = accessor.CorrelationInfo;
        }
    }
}

Or, alternatively when using custom correlation:

using Arcus.Observability.Correlation;

namespace Application
{
    public class OrderService
    {
        public OrderService(ICorrelationInfoAccessor<OrderCorrelationInfo> accessor)
        {
             OrderCorrelationInfo correlationInfo = accessor.CorrelationInfo;
        }
    }
}