Metrics Information
Tracking and exposing metrics information is enabled by the telemetry feature flag.
Please refer to this documentation
for more information about feature flags.
The metrics information is intended to be handled by Prometheus .
Therefore, in the config.toml file, the entry server.metrics_address should be configured
to listen for access from the Prometheus server. The listening address is restricted by default
to access from localhost.
[server]
metrics_address = "127.0.0.1"
metrics_port = 9100
In this case, we configure it to be accessible from anywhere for testing purposes, but in a production environment, it’s advisable to restrict access to only the Prometheus server.
[server]
metrics_address = "0.0.0.0"
metrics_port = 9100
After starting the DataFusion Server and making API accesses,
try accessing the /metrics endpoint on the configured server port.
curl http://127.0.0.1:9100/metrics
You should receive a response like this.
# TYPE http_requests_total counter
http_requests_total{method="GET",path="/session/create",status="200"} 1
http_requests_total{method="POST",path="/session/:session_id/datasource",status="204"} 1
# TYPE flight_requests_total counter
flight_requests_total{method="get_schema",status="ok"} 1
flight_requests_total{method="do_get",status="error"} 1
flight_requests_total{method="do_get",status="ok"} 1
# TYPE flight_requests_duration_seconds summary
flight_requests_duration_seconds{method="do_get",status="error",quantile="0"} 0.000506459
flight_requests_duration_seconds{method="do_get",status="error",quantile="0.5"} 0.0005064423655961616
flight_requests_duration_seconds{method="do_get",status="error",quantile="0.9"} 0.0005064423655961616
flight_requests_duration_seconds{method="do_get",status="error",quantile="0.95"} 0.0005064423655961616
flight_requests_duration_seconds{method="do_get",status="error",quantile="0.99"} 0.0005064423655961616
flight_requests_duration_seconds{method="do_get",status="error",quantile="0.999"} 0.0005064423655961616
flight_requests_duration_seconds{method="do_get",status="error",quantile="1"} 0.000506459
Currently, following metric names and labels are exposed:
| metric name | value | labels |
|---|---|---|
| memory_usage_bytes | Physical memory usage | |
| virtual_memory_usage_bytes | Virtual (swap) memory usage | |
| http_requests_total | Total number of HTTP requests received | method, path, status |
| http_requests_duration_seconds | Latency from request to response | method, path, status |
| flight_requests_total | Total number of Flight gRPC requests received | method, status |
| flight_requests_duration_seconds | Latency from request to response | method, status |
| session_contexts_total | Total number of contexts created | |
| session_context_duration_seconds | Lifetime per session | |
| data_source_registrations_total | Total number of data source loaded | scheme, format |
Detailed configuration information about Prometheus is not provided here.
There are shell scripts and configuration file in the example/prometheus-docker directory
for starting and stopping Prometheus with Docker, so let them a try.