Metrics Exporter - OTLP

Status: Stable

General

OTLP Metrics Exporter is a Push Metric Exporter which sends metrics via the OpenTelemetry Protocol.

OTLP Metrics Exporter MUST provide configuration to influence the MetricReader output temporality as a function of instrument kind. This option MAY be named temporality, and MUST set temporality preference to Cumulative for all instrument kinds by default.

OTLP Metrics Exporter MUST provide configuration to influence the MetricReader default aggregation as a function of instrument kind. This option MAY be named default_aggregation, and MUST set the default aggregation for all instrument kinds by default.

The exporter MUST provide configuration according to the OpenTelemetry Protocol Exporter specification.

If a language provides a mechanism to automatically configure a MetricReader to pair with the associated Exporter (e.g., using the OTEL_METRICS_EXPORTER environment variable), then by default:

  • The exporter MUST be paired with a periodic exporting MetricReader.
  • The exporter MUST configure the default aggregation temporality on the basis of instrument kind using the OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE variable as described below.
  • The exporter MUST configure the default aggregation on the basis of instrument kind using the OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION variable as described below if it is implemented.

Additional Environment Variable Configuration

NameDescriptionDefault
OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCEConfigure the exporter’s aggregation temporality option (see above) on the basis of instrument kind.cumulative
OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATIONConfigure the exporter’s default_aggregation option (see above) for Histogram instrument kind.explicit_bucket_histogram

The recognized (case-insensitive) values for OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE are:

  • Cumulative: Choose cumulative aggregation temporality for all instrument kinds.
  • Delta: Choose Delta aggregation temporality for Counter, Asynchronous Counter and Histogram instrument kinds, choose Cumulative aggregation for UpDownCounter and Asynchronous UpDownCounter instrument kinds.
  • LowMemory: This configuration uses Delta aggregation temporality for Synchronous Counter and Histogram and uses Cumulative aggregation temporality for Synchronous UpDownCounter, Asynchronous Counter, and Asynchronous UpDownCounter instrument kinds.

The “LowMemory” choice is so-named because the SDK can under certain conditions use less memory in this configuration than the others. Comparatively, the “cumulative” choice forces the SDK to maintain a delta-to-cumulative conversion for Synchronous Counter and Histogram instruments, while the “delta” choice forces the SDK to maintain a cumulative-to-delta conversion for Asynchronous Counter instruments.

The recognized (case-insensitive) values for OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION are:

References