fix(spans): Allow spans namespace for usage metric (#3723)

#3719 enabled
`c:spans/usage@none` for plans that do not extract other span metrics.
We also need to allow the namespace otherwise they will be dropped with
outcome `filtered:disabled-namespace`.

relay-dynamic-config/src/defaults.rs

@@ -71,10 +71,7 @@ pub fn add_span_metrics(project_config: &mut ProjectConfig) {
  let features = &project_config.features;
 
  // If there are any spans in the system, extract the usage metric for them:
- let any_spans = features.has(Feature::ExtractSpansFromEvent)
- || features.has(Feature::StandaloneSpanIngestion)
- || features.has(Feature::ExtractCommonSpanMetricsFromEvent);
- if any_spans {
+ if features.produces_spans() {
  config.metrics.push(MetricSpec {
  category: DataCategory::Span,
  mri: "c:spans/usage@none".into(),

relay-dynamic-config/src/feature.rs

@@ -143,6 +143,13 @@ impl FeatureSet {
  pub fn has(&self, feature: Feature) -> bool {
  self.0.contains(&feature)
  }
+
+ /// Returns `true` if any spans are produced for this project.
+ pub fn produces_spans(&self) -> bool {
+ self.has(Feature::ExtractSpansFromEvent)
+ || self.has(Feature::StandaloneSpanIngestion)
+ || self.has(Feature::ExtractCommonSpanMetricsFromEvent)
+ }
 }
 
 impl FromIterator<Feature> for FeatureSet {

relay-server/src/services/project/metrics.rs

@@ -125,10 +125,7 @@ fn is_metric_namespace_valid(state: &ProjectState, namespace: MetricNamespace) -
  match namespace {
  MetricNamespace::Sessions => true,
  MetricNamespace::Transactions => true,
- MetricNamespace::Spans => {
- state.has_feature(Feature::ExtractCommonSpanMetricsFromEvent)
- || state.has_feature(Feature::StandaloneSpanIngestion)
- }
+ MetricNamespace::Spans => state.config.features.produces_spans(),
  MetricNamespace::Profiles => true,
  MetricNamespace::Custom => state.has_feature(Feature::CustomMetrics),
  MetricNamespace::Stats => true,