[CAMEL-19469] camel-opentelemetry: Context not propagated correctly when tracing bean or processor invocations with @WithSpan

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.20.5, 4.0-M3
• Component/s: camel-opentelemetry
• Estimated Complexity: Unknown
• Assignee: Unassigned
• Reporter: James Netherton
• Created: 19/Jun/23 09:00
• Updated: 22/Mar/24 09:06

Description

OpenTelemetry enables you to trace arbitrary method invocations by tagging them with the @WithSpan annotation:

https://opentelemetry.io/docs/instrumentation/java/automatic/annotations/#creating-spans-around-methods-with-withspan

For some scenarios, the tracing context does not seem to get propagated and the resulting spans end up being disassociated. For example:

from("timer:tick?period=5s)
    .process("myProcessor");    

public class MyProcessor implements Processor {
    @WithSpan
    @Override
    public void process(Exchange exchange) {
        // Useful work here...
    }
}

This results in 2 spans. One for timer:tick & another for MyProcessor. The problem is that the parent span for MyProcessor is not set, so they appear as 2 distinct traces.

There is a workaround where you can configure the route like this and the span hierarchy ends up being correct:

from("timer:tick?period=5s")
    .to("direct:start");

from("direct:start")
    .process("myProcessor");

There's some more background in the original issue reported on Camel Quarkus:

https://github.com/apache/camel-quarkus/issues/4981

There's also a reproducer project here:

https://github.com/jamesnetherton/camel-opentelemetry-demo

Issue Links

• is related to: CAMEL-19667 camel-tracing: Context is not propagated from exchange header to OpenTelemetry Context