Configure Observability

Prometheus metrics, OpenTelemetry tracing, and request logging configuration for the interceptor and scaler

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The interceptor and the external scaler expose metrics and tracing data to help monitor HTTP traffic and scaling behavior. Both components share the same set of observability environment variables, configured through the interceptor.extraEnvs and scaler.extraEnvs Helm values respectively.

Prometheus metrics

Both the interceptor and the scaler expose Prometheus metrics at /metrics on port 2223. This is enabled by default.

Env var	Default	Description
`OTEL_PROM_EXPORTER_ENABLED`	`true`	Enable the Prometheus metrics endpoint.
`OTEL_PROM_EXPORTER_PORT`	`2223`	Port for the Prometheus metrics endpoint.

See Metrics Reference for the full list of metrics and labels.

OpenTelemetry tracing

Enable distributed tracing via OTLP. The following example enables tracing for both the interceptor and the scaler:

helm upgrade http-add-on kedacore/keda-add-ons-http \
  --namespace keda \
  --set interceptor.extraEnvs.OTEL_EXPORTER_OTLP_TRACES_ENABLED=true \
  --set interceptor.extraEnvs.OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc \
  --set interceptor.extraEnvs.OTEL_EXPORTER_OTLP_ENDPOINT=http://<your-otel-collector>:4317 \
  --set scaler.extraEnvs.OTEL_EXPORTER_OTLP_TRACES_ENABLED=true \
  --set scaler.extraEnvs.OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc \
  --set scaler.extraEnvs.OTEL_EXPORTER_OTLP_ENDPOINT=http://<your-otel-collector>:4317

Both components use W3C TraceContext and Baggage propagation. The scaler additionally instruments all gRPC server calls via otelgrpc when tracing is enabled.

Env var	Default	Description
`OTEL_EXPORTER_OTLP_TRACES_ENABLED`	`false`	Enable OTLP trace export.
`OTEL_EXPORTER_OTLP_TRACES_PROTOCOL`	`console`	Exporter protocol (`grpc`, `http/protobuf`, `console`).
`OTEL_EXPORTER_OTLP_ENDPOINT`	—	Collector endpoint URL.
`OTEL_EXPORTER_OTLP_HEADERS`	—	Authentication headers (e.g., `api-key=<token>`).
`OTEL_EXPORTER_OTLP_TRACES_TIMEOUT`	`10s`	Timeout for trace export requests.

OpenTelemetry metrics

Enable OTLP metrics export alongside or instead of Prometheus:

helm upgrade http-add-on kedacore/keda-add-ons-http \
  --namespace keda \
  --set interceptor.extraEnvs.OTEL_EXPORTER_OTLP_METRICS_ENABLED=true \
  --set interceptor.extraEnvs.OTEL_EXPORTER_OTLP_ENDPOINT=http://<your-otel-collector>:4317 \
  --set scaler.extraEnvs.OTEL_EXPORTER_OTLP_METRICS_ENABLED=true \
  --set scaler.extraEnvs.OTEL_EXPORTER_OTLP_ENDPOINT=http://<your-otel-collector>:4317

Env var	Default	Description
`OTEL_EXPORTER_OTLP_METRICS_ENABLED`	`false`	Enable OTLP metrics export.
`OTEL_EXPORTER_OTLP_ENDPOINT`	—	Collector endpoint URL (shared with traces if set).
`OTEL_EXPORTER_OTLP_HEADERS`	—	Authentication headers (shared with traces if set).
`OTEL_METRIC_EXPORT_INTERVAL`	`60s`	Interval between periodic metric exports.

Request logging

Enable Combined Log Format request logging (interceptor only):

helm upgrade http-add-on kedacore/keda-add-ons-http \
  --namespace keda \
  --set interceptor.extraEnvs.KEDA_HTTP_LOG_REQUESTS=true

What’s Next

Metrics Reference — detailed Prometheus metric definitions.
Environment Variables Reference — all observability-related environment variables.