Exclude Dimension Setting in Span Metrics Connector Does Not Apply to Non-Default Dimensions

[EOjeah]

Component(s)

connector/spanmetrics
No response

What happened?

Description

The spanmetricsconnector component in the OpenTelemetry Collector has a setting called exclude_dimensions that is intended to exclude specific dimensions from the metrics. This setting works correctly for the default dimensions, which are service.name, span.name, span.kind, and status.code. However, it does not work for dimensions that are added by process tags such as host.name by any processors before the spanmetricsconnector

Steps to Reproduce

Send sample zipkin span to the otel collector traces pipeline with the span metrics connector and prometheus output for metrics

[
    {
        "traceId": "30101010101",
        "id": "1",
        "kind": "SERVER",
        "name": "GET /api",
        "timestamp": 1697040000000000,
        "duration": 2000001,
        "localEndpoint": {
            "serviceName": "example"
        },
        "tags": {
            "http.route.name": "api.example.com",
            "host.name": "ec2-10.1.1.1.amazonaws.com"
        }
    }
]

Expected Result

host_name is not part of the metric dimension

calls_total{service_name="example", span_kind="SPAN_KIND_SERVER", status_code="STATUS_CODE_UNSET"}

Actual Result

host_name metric is included with the metric

calls_total{host_name="ec2-10.1.1.1.amazonaws.com", service_name="example", span_kind="SPAN_KIND_SERVER", status_code="STATUS_CODE_UNSET"}

Collector version

v0.103.0

Environment information

Environment

Ubuntu 22.04.4 LTS

OpenTelemetry Collector configuration

receivers:
  zipkin:

connectors:
  spanmetrics:
    exclude_dimensions: ['host.name']
    
exporters:
  prometheus:
service:
  pipelines:
    traces:
      receivers: [zipkin]
      exporters: [spanmetrics]
    metrics:
      receivers: [spanmetrics]
      exporters: [prometheus]

Log output

No response

Additional context

No response

[EOjeah]

Just realised I didn't add the component, closing this for #34102