Why should you care?

You care about this when a checkout fails and you must trace it across Gateway → Order → Payment → RabbitMQ in minutes, not days.

See it live — copy this example

Create a Web API project (dotnet new webapi), paste the code, then run dotnet run.

builder.Services.AddOpenTelemetry()
    .WithTracing(b => b
        .AddAspNetCoreInstrumentation()
        .AddHttpClientInstrumentation()
        .AddSource("MassTransit"));

Log.Information("Order {OrderId} placed", order.Id);

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

What happened?

• The example shows Distributed Tracing wired into Order Service.
• Read each line, run it locally, then change one setting and observe what breaks or improves.
• That is how teams learn in production too — small experiments, not big bang rewrites.

Try it yourself

1. Open or create the ShopNest project area for Order Service.
2. Apply the Distributed Tracing pattern from the lesson example.
3. Run dotnet build && dotnet run (or docker compose up when the lesson uses containers).
4. Change a string or number in the example and run again — predict the output first.
5. Break the code on purpose (remove a semicolon), read the compiler error, then fix it.

Remember

Distributed Tracing connects to Order Service in ShopNest Cloud-Native. Practice by editing the example yourself — do not only read. Move on when you can explain this topic in your own words without looking.

Real-world: Flipkart Big Billion Day checkout

During peak sales, Order and Payment services scale independently. RabbitMQ buffers spikes so Payment workers catch up without blocking the mobile app.

Outcome: Checkout returns in under 500ms while payment completes in the background — shoppers see clear status updates.