Grafana k6 can push test run metrics in the OpenTelemetry (OTEL) metrics format to an OTEL metrics collector or a metrics backend that supports the OTEL metrics format by using the experimental OpenTelemetry output --out experimental-opentelemetry.
For any feedback, bugs or suggestions feel free to open an issue directly in the k6 repository. Contributions are also welcome!
Metrics mapping
k6 converts all
k6 metric types to an equivalent OTEL metric type, and all k6 tags to OTEL attributes. When possible, the units are also passed with the metrics.
k6 Metric
OpenTelemetry Metric
Counter
Float64CounterOption
Gauge
Float64ObservableGauge
Rate
Exported as a single Int64Counter counter named metric_name with an attribute condition that can have two values: zero and nonzero.
Trend
Float64Histogram
Caution
Prior to k6 v1.4.0, Rate metrics were exported as two separate counters: metric_name.occurred and metric_name.total. You can revert to this legacy behavior by setting the environment variable K6_OTEL_SINGLE_COUNTER_FOR_RATE=false. However, this legacy approach is deprecated and will be removed in a future release.
Run the k6 test
You can use the --out experimental-opentelemetry option when running your tests to use this extension:
Bash
Bash
K6_OTEL_GRPC_EXPORTER_INSECURE=true K6_OTEL_METRIC_PREFIX=k6_ k6 run --tag test-id=123 -o experimental-opentelemetry examples/script.js
Configuration
The following options can be configured:
Name
Value
K6_OTEL_SERVICE_NAME
The name of the service to use for the metrics exporting. Default value is k6.
K6_OTEL_SERVICE_VERSION
The version of the service to use for the metrics exporting. Default is version of the k6, e.g. v0.54.0
K6_OTEL_METRIC_PREFIX
Metric prefix. Default is empty.
K6_OTEL_FLUSH_INTERVAL
How frequently to flush metrics from k6 metrics engine. Default is 1s.
K6_OTEL_EXPORT_INTERVAL
Configures the intervening time between metrics exports. Default is 10s.
K6_OTEL_HEADERS
Configures headers in the W3C Correlation-Context format without additional semi-colon delimited metadata (i.e. “k1=v1,k2=v2”). Passes the headers to the exporter.
K6_OTEL_TLS_INSECURE_SKIP_VERIFY
Disables server certificate verification.
K6_OTEL_TLS_CERTIFICATE
Configures the path to the root CA certificate file for TLS credentials. If it is not provided but TLS is enabled then the host’s root CAs set is used.
K6_OTEL_TLS_CLIENT_CERTIFICATE
Configures the path to the client certificate file.
K6_OTEL_TLS_CLIENT_KEY
Configures the path to the client key file.
K6_OTEL_EXPORTER_TYPE
Configures the type of exporter to use. Valid options are http and grpc. Default is grpc.
K6_OTEL_GRPC_EXPORTER_INSECURE
Disables client transport security for the gRPC exporter.
K6_OTEL_GRPC_EXPORTER_ENDPOINT
Configures the gRPC exporter endpoint. Default is localhost:4317.
K6_OTEL_HTTP_EXPORTER_INSECURE
Disables client transport security for the HTTP exporter.
K6_OTEL_HTTP_EXPORTER_ENDPOINT
Configures the HTTP exporter endpoint. Must be host and port only, without scheme. Default is localhost:4318.
K6_OTEL_HTTP_EXPORTER_URL_PATH
Configures the HTTP exporter path. Default is /v1/metrics.
K6_OTEL_SINGLE_COUNTER_FOR_RATE
Controls how Rate metrics are exported. When set to true (default), metrics are exported as a single counter with an attribute. When set to false, the legacy method is used, creating two separate counters. The legacy method is deprecated and will be removed in a future release.
You can also use the OpenTelemetry SDK configuration environment variables to configure the OpenTelemetry output, like the gRPC exporter configuration. The K6_OTEL_* environment variables take precedence over the OpenTelemetry SDK configuration environment variables.
