Endb exposes plaintext logs, Prometheus metrics, and optional OpenTelemetry tracing. Any one, or a combination, of these can be used to monitor an Endb instance.

Some monitoring options are offered as flags. Set flags by setting the environment variable to 0 or 1 (ex. ENDB_LOG_ANSI=0).


By default, endb logs to STDOUT with a log level of endb=INFO.

Adjust the log level with the ENDB_LOG_LEVEL environment variable. Endb uses Rust Logging and more details about log levels are available in that document.

Other flags include:

  • ENDB_LOG_ANSI - turns ANSI terminal colour output on or off (on by default)
  • ENDB_LOG_THREAD_IDS - set to enable or disable logging of thread ids (enabled by default)


docker run --rm -e ENDB_LOG_LEVEL=endb=DEBUG -e ENDB_LOG_ANSI=0 -e ENDB_LOG_THREAD_IDS=1 -p 3803:3803 -v demo_data:/app/endb_data


A Prometheus endpoint is available at /metrics. This endpoint is enabled by default. If your Endb instance is running locally, you can view metrics in a browser at http://localhost:3803/metrics

The Prometheus tracing level defaults to endb=DEBUG. Set the tracing level with ENDB_TRACING_LEVEL.


To enable OpenTelemetry, set ENDB_TRACING_OTEL=1 and OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317/ Configuration options for the OTLP exporter and additional OTLP environment variables may also prove useful for configuration.

The OpenTelemetry tracing level defaults to endb=DEBUG. Set the tracing level with ENDB_TRACING_LEVEL.

At the moment, only gRPC metrics are exposed, not HTTP.


Endb exposes a number of metrics to the Prometheus endpoint and OpenTelemetry. These can be useful in debugging performance of applications connected to Endb.


  • query_real_time_duration_seconds
  • query_gc_run_time_duration_seconds
  • query_consed_bytes
  • http_request_duration_seconds


  • queries_active
  • interactive_transactions_active
  • buffer_pool_usage_bytes
  • dynamic_space_usage_bytes

Monotonic Counters

  • websocket_message_internal_errors_total
  • object_store_read_bytes_total
  • object_store_written_bytes_total
  • queries_total
  • transactions_conflicted_total
  • transactions_committed_total
  • transactions_prepared_total
  • transactions_retried_total
  • wal_read_bytes_total
  • wal_written_bytes_total
  • http_requests_total


Endb exposes a variety of tracing spans to OpenTelemetry. Tracing data is mostly useful if your Endb instance is not performing in the way you expect.

  • buffer_pool_eviction
  • build_info
  • commit
  • compaction
  • constraints
  • gc
  • index
  • log_replay
  • log_rotation
  • object_store_delete
  • object_store_get
  • object_store_list
  • object_store_put
  • query
  • shutdown
  • snapshot
  • startup
  • wal_append_entry
  • wal_read_next_entry
  • wal_fsync
  • websocket_connections_active
  • websocket_message_duration_seconds
  • websocket_messages_total