I am trying to integrate OpenTelemetry with my existing Spring Boot application using the Zero-code instrumentation Spring Boot Starter. I followed the official documentation and configured the following in my application.yml file:

otel:
  propagators:
    - tracecontext
  exporter:
    otlp:
      traces:
        endpoint: 'http://<otel_collector_server>:4319/v1/traces'
        protocol: http/protobuf
    metrics:
      exporter: none
    logs:
      exporter: none

With this configuration, the application successfully exports traces to the OpenTelemetry Collector, and I can view the traces in the Grafana dashboard.

However, the traces only show high-level information about which endpoints were hit across different services. They do not provide details about:

Which methods were called after hitting an endpoint.
The execution time of those methods.
I want to capture method-level tracing to see which methods were invoked as part of a request and how much time they took.

What I’ve Tried:

1. I confirmed that the opentelemetry-spring-boot-starter dependency is added to my project.
2. Verified that the traces are being exported to the collector.

Questions:

1. Is there any additional configuration needed to capture method-level traces automatically?
2. Do I need to use @WithSpan or manual instrumentation even though I want to rely on Zero-code instrumentation?
3. Is there a way to enable this through configuration, or do I need to extend the instrumentation explicitly?

Java version: 21

Spring Boot version: 3.3.0

OpenTelemetry Spring Boot Starter version: 2.6.0