TracingHeaders message field

[gfx687]

Hello, I am trying to integrate CAP with OpenTracing.

I have found the Helper.AddTracingHeaderProperty method that looks like exactly for this purpose, but any data added as TracingHeaders will be overwritten in BasePublishMessageSender.SendWithoutRetryAsync with just empty TracingHeaders object. How can I add tracing metadata to messages? Or should I just add my logic and content field for it?

P.S.

1. Here new TracingHeaders object are set to eventData.Headers (https://github.com/dotnetcore/CAP/blob/master/src/DotNetCore.CAP/IPublishMessageSender.Base.cs#L160)
2. And here my TracingHeaders data in Content overwritten because tracingResult.Item2 != null always true (because of p.1) (https://github.com/dotnetcore/CAP/blob/master/src/DotNetCore.CAP/IPublishMessageSender.Base.cs#L72)

[yang-xiaodong]

Hello ,

I need some time to get familiar with the OpenTracing part again. Here is an example that was tested last year. Maybe it works for you?

https://github.com/yang-xiaodong/OpenTracing.Contrib.CAP
https://github.com/SkyAPM/SkyAPM-dotnet/tree/master/src/SkyApm.Diagnostics.CAP

PR is welcome!

[gfx687]

Yes, I got it now. Thanks!

[gfx687]

Hello again (reopened this issue instead of creating a new one)

I want to add tracing metadata to Content before saving it to a database (CapDiagnosticListenerExtensions.WritePublishMessageStoreBefore) so I will be able to create a new Span based on saved in DB. This way I will have the same TraceId for a whole process (from controller logic to consuming message by subscriber).
But the problem is: WritePublishMessageStoreBefore method sends content as a direct property of an anonymous object, so I cannot change it (add tracing metadata to message)
Is there any way to change Content value without writing additional layer of logic before sending a message to CapBus?

[gfx687]

Hello again!

In the last comment, I meant that I want to be able to add TracingHeaders to message on CapDiagnosticListenerExtensions.WritePublishMessageStoreBefore event, just like in CapBeforePublish and CapBeforeConsume.
I added small Pull Request with an example of what I want. I hope these changes won't break any backward compatibility

link: #380

[yang-xiaodong]

Hello,

Thanks for your PR, it looks good!

The extra information I want you to know :

We will make some major updates in v2.7 (maybe named v3.0) with additional header information and code refactoring.

But it still takes a while time, I think we can merge the PR #380 and release it in the v2.6 so that it can be used for you.

Regarding the latest version about the tracing changes you can subscribe this issue to receive notice.

Thanks

[yang-xiaodong]

@gfx687 I have released version 2.6.0-preview-82001197 to NuGet, you can try it

[gfx687]

Great, thanks! Now everything works for me
(I am not sure if I should close an issue with an "enhancement" label by myself, so I will leave it to you if needed)

[yang-xiaodong]

Hello @gfx687 ,

In v3.0, we have refactoring the Diagnostics. You can see how to connect APM at the Skywalking C# agent code.

Agent code:

https://github.com/yang-xiaodong/SkyAPM-dotnet/tree/master/src/SkyApm.Diagnostics.CAP

SkyWalking UI: