[
https://issues.apache.org/jira/browse/CAMEL-23349?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18074777#comment-18074777
]
Pasquale Congiusti commented on CAMEL-23349:
--------------------------------------------
I haven't yet had a look to the PR solution proposed. I'll do during the day.
However I'd like to point some important concept around the design of the
telemetry in Camel. Each technology implementation specific should be
abstracted into some generic concept and designed accordingly. Camel is a
general purpose framework and we must make sure to maintain generic design that
can make every application compliant. We need to reason if and how to port each
feature of the implementation into Camel in a manner that makes it independent,
decoupled, maintainable, extendible and compliant with design.
The baggage concept seems to be very specific to otel, so, we need to make it
sure to port it in a way that can be generalized.
> Camel OpenTelemetry2 programmatic baggage management
> ----------------------------------------------------
>
> Key: CAMEL-23349
> URL: https://issues.apache.org/jira/browse/CAMEL-23349
> Project: Camel
> Issue Type: Improvement
> Components: camel-opentelemetry
> Affects Versions: 4.18.1, 4.19.0
> Reporter: Bjorn Beskow
> Priority: Major
>
> With Camel OpenTelemetry2 and OpenTelemetry spring boot starter, most aspects
> of Span Customization such as adding attributes, events and creating nested
> spans can be done using the OpenTelemetry apis. Programmatically adding OTEL
> baggage is however an exception. The typical use case for OTEL baggage is to
> allow for small pieces of contextual data that need to travel with a request
> across distributed service boundaries, independent of any single span. In our
> business context, it is in the form of a "business correlation id" that is
> captured from a header or from the message payload as the very first
> processor of a boundary component, and should be available to all downstream
> components.
> The OTEL api itself cannot easily be used to add baggage items to a Camel
> route, due to `Scope` handling: Baggage must be added to a baggage scope, and
> is visible and propagated during the lifetime of the scope. The OTEL api
> looks like this:
> // Create baggage with an entry
> Baggage baggage = Baggage.current().builder()
> .put("user-id", "12345")
> .build();
> // Attach baggage to current context
> Context contextWithBaggage = Context.current().with(baggage);
> // Make it current (scoped)
> try (var scope = contextWithBaggage.makeCurrent())
> { // Your code here - baggage is now active }
> Doing this in a processor, the scope instance must be kept open as long as
> needed, typically until the end of the exchange. In theory, the following
> simple albeit brittle solution should work:
>
> Baggage baggage = Baggage.current().toBuilder()
> .put("user-id", "12345")
> .build();
> Context ctxWithBaggage = Context.current().with(baggage);
> Scope scope = ctxWithBaggage.makeCurrent();
> exchange.getExchangeExtension().addOnCompletion(new SynchronizationAdapter() {
> @Override public void onDone(Exchange exchange)
> { scope.close(); }
> });
> In practice however, this doesn't work. A (final) baggageScope is already
> (automatically) created at the start of a Camel route execution, stored on
> the exchange as part of a wrapped instance of
> org.apache.camel.opentelemetry2.OpenTelemetrySpanAdapter and properly closed
> at the end of the route. It is this baggageScope that is passed to the OTEL
> propagator, not the scope created programmatically as in the example above.
> Hence the programmatically added baggage entry will not be propagated.
> To my understanding, the simplest way to programmatically add baggage items
> would be to allow for mutating the baggage scope stored in the
> org.apache.camel.opentelemetry2.OpenTelemetrySpanAdapter. The required pieces
> are already present, but would need to be exposed in a public API (currently,
> both context, baggage and baggage scope are protected).
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
