# Observability | | | | --- | --- | | | This documentation is for
an as-yet unreleased
version of Cerbos PDP. Choose 0.53.0 from the version picker at the top right or navigate to [https://docs.cerbos.dev](https://docs.cerbos.dev/) for the latest version. | Cerbos is designed from the ground up to be cloud native and has first-class support for observability via OpenTelemetry metrics and distributed traces. ## Metrics By default, Cerbos exposes a metrics endpoint at `/_cerbos/metrics` that can be scraped by Prometheus or other metrics scrapers that support the Prometheus metrics format. This endpoint can be disabled by setting `server.metricsEnabled` configuration value to `false` (see [Server block](https://docs.cerbos.dev/cerbos/prerelease/configuration/server)). Cerbos also has support for OpenTelemetry protocol (OTLP) push metrics. It can be configured using [OpenTelemetry environment variables](https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/). The following environment variables are supported. | Environment variable | Description | | --- | --- | | `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT or OTEL_EXPORTER_OTLP_ENDPOINT` | Address of the OTLP metrics receiver (for example: `https://localhost:9090/api/v1/otlp/v1/metrics`). If not defined, OTLP metrics are disabled. | | `OTEL_EXPORTER_OTLP_METRICS_INSECURE or OTEL_EXPORTER_OTLP_INSECURE` | Skip validating the TLS certificate of the endpoint | | `OTEL_EXPORTER_OTLP_METRICS_CERTIFICATE or OTEL_EXPORTER_OTLP_CERTIFICATE` | Path to the certificate to use for validating the server’s TLS credentials. | | `OTEL_EXPORTER_OTLP_METRICS_CLIENT_CERTIFICATE or OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE` | Path to the client certificate to use for mTLS | | `OTEL_EXPORTER_OTLP_METRICS_CLIENT_KEY or OTEL_EXPORTER_OTLP_CLIENT_KEY` | Path to the client key to use for mTLS | | `OTEL_EXPORTER_OTLP_METRICS_PROTOCOL or OTEL_EXPORTER_OTLP_PROTOCOL` | OTLP protocol. Supported values are `grpc` and `http/protobuf`. Defaults to `grpc`. | | `OTEL_METRIC_EXPORT_INTERVAL` | The export interval in milliseconds. Defaults to 60000. | | `OTEL_METRIC_EXPORT_TIMEOUT` | Timeout for exporting the data in milliseconds. Defaults to 30000. | | `OTEL_METRICS_EXPORTER` | Set to `otlp` to enable the OTLP exporter. Defaults to `prometheus`. | Refer to [https://opentelemetry.io/docs/specs/otel/protocol/exporter/](https://opentelemetry.io/docs/specs/otel/protocol/exporter/) for more information about exporter configuration through environment variables. Note that the OpenTelemetry Go SDK used by Cerbos might not have full support for some of the environment variables listed on the OpenTelemetry specification. | | | | --- | --- | | | `OTEL_METRICS_EXPORTER` and `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT` are the only required environment variables to enable OTLP metrics. | ## Traces Cerbos supports distributed tracing to provide insights into application performance and request lifecycle. Traces from Cerbos can be exported to any compatible collector that supports the OpenTelemetry protocol (OTLP). Trace configuration should be done using [OpenTelemetry environment variables](https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/). The following environment variables are supported. | | | | --- | --- | | | If you are upgrading from a Cerbos version older than 0.33.0, refer to [migration instructions](https://docs.cerbos.dev/cerbos/prerelease/configuration/tracing#migration) for information about mapping file-based configuration to environment variables. | | Environment variable | Description | | --- | --- | | `OTEL_SERVICE_NAME` | Service name reported in the traces. Defaults to `cerbos`. | | `OTEL_TRACES_SAMPLER` | [Trace sampler](https://opentelemetry.io/docs/specs/otel/trace/sdk/#sampling). Defaults to `parentbased_always_off`. Supported values:
`always_on`
Record every trace.
`always_off`
Don’t record any traces.
`traceidratio`
Record a fraction of traces based on ID. Set `OTEL_TRACES_SAMPLER_ARG` to a value between 0 and 1 to define the fraction.
`parentbased_always_on`
Record all traces except those where the parent span is not sampled.
`parentbased_always_off`
Don’t record any traces unless the parent span is sampled.
`parentbased_traceidratio`
Record a fraction of traces where the parent span is sampled. Set `OTEL_TRACES_SAMPLER_ARG` to a value between 0 and 1 to define the fraction. | | `OTEL_TRACES_SAMPLER_ARG` | Set the sampling ratio when `OTEL_TRACES_SAMPLER` is a ratio-based sampler. Defaults to `0.1`. | | `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT or OTEL_EXPORTER_OTLP_ENDPOINT` | Address of the OTLP collector (for example: `https://localhost:4317`). If not defined, traces are disabled. | | `OTEL_EXPORTER_OTLP_TRACES_INSECURE or OTEL_EXPORTER_OTLP_INSECURE` | Skip validating the TLS certificate of the endpoint | | `OTEL_EXPORTER_OTLP_TRACES_CERTIFICATE or OTEL_EXPORTER_OTLP_CERTIFICATE` | Path to the certificate to use for validating the server’s TLS credentials. | | `OTEL_EXPORTER_OTLP_TRACES_CLIENT_CERTIFICATE or OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE` | Path to the client certificate to use for mTLS | | `OTEL_EXPORTER_OTLP_TRACES_CLIENT_KEY or OTEL_EXPORTER_OTLP_CLIENT_KEY` | Path to the client key to use for mTLS | | `OTEL_EXPORTER_OTLP_TRACES_PROTOCOL or OTEL_EXPORTER_OTLP_PROTOCOL` | OTLP protocol. Supported values are `grpc` and `http/protobuf`. Defaults to `grpc`. | | | | | --- | --- | | | `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT` is the only required environment variable to enable OTLP trace exports.