[Vert.x 4] Incorrect HTTP metric reporting

[cescoffier]

Describe the bug

An assertion from io.quarkus.it.micrometer.prometheus.PrometheusMetricsRegistryTest does not pass with Vert.x 4.

With an endpoint like:

@GET
@Path("item/{id}")
public String item(@PathParam("id") String id) {
    return "return message with id " + id;
}

The reported metrics uses the actual path instead of the parameterized path:

http_server_requests_seconds_count{env="test",method="GET",outcome="SUCCESS",registry="prometheus",status="200",uri="/message/item/123",} 1.0
http_server_requests_seconds_sum{env="test",method="GET",outcome="SUCCESS",registry="prometheus",status="200",uri="/message/item/123",} 0.002675179

This will lead to OOM as for each unique id, a metric will be captured.

Expected behavior

It should report:

http_server_requests_seconds_count{env="test",method="GET",outcome="SUCCESS",registry="prometheus",status="200",uri="/message/item/{id}",} 1.0
http_server_requests_seconds_sum{env="test",method="GET",outcome="SUCCESS",registry="prometheus",status="200",uri="/message/item/{id}",} 0.002675179

To Reproduce

In the vertx-snapshot branch:

• Open io.quarkus.it.micrometer.prometheus.PrometheusMetricsRegistryTest
• Uncomment line 137
• Run -> boom

Note: The assertion has been commented to avoid being stuck. However, this issue should be considered critical.

[cescoffier]

I was able to workaround the issue by specifying an explicit match pattern (/message/item/\[0-9]+=/message/item/{id}).

[ebullient]

This should be related to #15047 , but could also require micrometer to change how it is storing state against Vertx context.

[cescoffier]

@ebullient I've seen work around that. Are we good?

[ebullient]

Not quite. I put a lid on it (no OOM), if you want to try that and call that an answer to this issue..

Better recognition of patterns for client / server / etc. is still in flight.

[cescoffier]

@ebullient should this one be closed?

[ebullient]

Close as duplicate of #15231