Attribute `http_route` is not recorded by server metric when using servlet 2.0/3.0.

[k3v1n1k88]

Describe the bug

While using the OpenTelemetry Java agent on an application that uses Servlet 2.0/3.0, the http_route attribute is not recorded by the server metrics. It appears as follows:

http_server_request_duration_seconds_count{http_request_method="POST",http_response_status_code="200",network_protocol_version="1.1",otel_scope_name="io.opentelemetry.jetty-8.0",otel_scope_version="2.8.0-alpha",url_scheme="http"}

Steps to reproduce

Here's a clearer and more structured version of your steps:

1. Build HTTP Server Using Jetty Embedded 9.3 (Servlet 3.0)

   • Create an HTTP server using Jetty embedded 9.3, which supports Servlet 3.0.

2. Run Java Agent with Prometheus Exporter Enabled on Port 9464

   • Start the application with the OpenTelemetry Java agent and enable the Prometheus exporter on port 9464:

   java -javaagent:opentelemetry-javaagent.jar -Dotel.metrics.exporter=prometheus -Dotel.exporter.prometheus.port=9464 -jar myapp.jar

3. Send a Request to the Application

   • Make a request to the running application to trigger the server-side metrics:

   curl http://localhost:8080/your-endpoint

4. Load Metrics via Prometheus

   • Retrieve the metrics exposed by the Prometheus exporter:

   curl http://localhost:9464/metrics

5. Find the http_server_request_duration_seconds_count Metric

   • Look for the http_server_request_duration_seconds_count metric in the Prometheus output to check the recorded server request duration.

Expected behavior

The metric http_server_request_duration_seconds_count should contain the http_route attribute

http_server_request_duration_seconds_count{http_request_method="POST",http_response_status_code="200",http_route="/api/hello",network_protocol_version="1.1",otel_scope_name="io.opentelemetry.jetty-8.0",otel_scope_version="2.8.0-alpha",url_scheme="http"} 1

Actual behavior

The metric http_server_request_duration_seconds_count does not contain the http_route attribute.
http_server_request_duration_seconds_count{http_request_method="POST",http_response_status_code="200",network_protocol_version="1.1",otel_scope_name="io.opentelemetry.jetty-8.0",otel_scope_version="2.8.0-alpha",url_scheme="http"} 1`

Javaagent or library instrumentation version

2.8.0

Environment

JDK: OpenJDK 11.0.23
OS: Ubuntu 20.04
Jetty Embedded 9.3, Servlet 3

Additional context

No response

[laurit]

We believe that we can not provide a reasonable route based on just the servlets. If you are using a higher level framework it may be possible to instrument that framework to get a route.

[github-actions]

This has been automatically marked as stale because it has been marked as needing author feedback and has not had any activity for 7 days. It will be closed automatically if there is no response from the author within 7 additional days from this comment.

[devurandom]

@laurit Is there a way to add the http.route attribute from within my application code to http.server.request.duration measurements taken by the Java agent? I.e. "extend" the attribute set that the Java agent knew about with attributes that are only known once control has passed into my actual application and its HTTP router or HTTP handlers?

[trask]

check out HttpServerRoute