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This page lists the flags that control operational observability in Blnk Core. For how to think about logs, traces, and metrics, and for setup walkthroughs for Blnk Cloud and self-hosted export, see Monitoring in Blnk. These settings are independent from queue monitoring, which exposes a separate HTTP port for queue inspection.

Observability flags

BLNK_ENABLE_OBSERVABILITY=false
BLNK_CLOUD_DSN=
Outcome when setDefault
BLNK_ENABLE_OBSERVABILITYCore emits logs, traces, and metrics; /metrics is registered on the API port and worker monitoring port.false
BLNK_CLOUD_DSNBlnk Cloud DSN. Forwards logs, traces, and metrics to your Blnk Cloud monitoring project. Requires observability to be on. Format: https://<write-key>@<host>/<project-id>none
For /metrics bearer authentication, see Server & security.
BLNK_CLOUD_DSN has no effect when BLNK_ENABLE_OBSERVABILITY is false.
Exported logs have sensitive values redacted before they leave your instance.

Blnk Cloud DSN

Set the Blnk Cloud DSN when you export logs, traces, and metrics to Blnk Cloud monitoring:
  • Environment: BLNK_CLOUD_DSN
  • JSON: cloud_dsn
Requires enable_observability=true on the server and workers. See Quick setup: Blnk Cloud in Monitoring in Blnk.

OpenTelemetry endpoints

For self-hosted export, Blnk reads standard OpenTelemetry environment variables. Set them on both the server and worker. Observability must be enabled. Blnk exports traces and metrics over OTLP HTTP (port 4318 in typical Jaeger or Collector setups, not gRPC port 4317). Set a separate endpoint per signal on both the server and worker. Observability must be enabled.
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://jaeger:4318
OTEL_EXPORTER_OTLP_METRICS_ENDPOINT=http://otel-collector:4318
These variables are environment-only. They are not set in blnk.json.
Outcome when set
OTEL_EXPORTER_OTLP_TRACES_ENDPOINTOTLP HTTP endpoint for trace export.
OTEL_EXPORTER_OTLP_METRICS_ENDPOINTOTLP HTTP endpoint for metric push export.
Endpoint values accept common formats: host:port, http://host:port, or a full path such as http://jaeger:4318/v1/traces. Blnk normalizes the value before export.
Metrics push runs on a 60-second interval. Prometheus-compatible metrics are also available at /metrics on the API port and worker monitoring port regardless of OTLP settings. See Connect to other tools in Monitoring in Blnk. Logs are not exported through these endpoints. Collect process output with your log shipper, or set the Blnk Cloud DSN for managed log export.

Product telemetry

enable_telemetry is not operational observability. Turn on enable_observability for logs, traces, and metrics in Prometheus, Jaeger, or Blnk Cloud. enable_telemetry is optional product usage heartbeat telemetry for the Blnk team.
BLNK_ENABLE_TELEMETRY=false
DescriptionDefault
BLNK_ENABLE_TELEMETRYWhen true, Blnk sends optional product usage heartbeat telemetry so the Blnk team can understand usage trends.false

Need help?

We are very happy to help you make the most of Blnk, regardless of whether it is your first time or you are switching from another tool. To ask questions or discuss issues, please contact us or join our Discord community.