Exporters

An exporter receives every finished query and sends it somewhere. Four ship with the package; writing your own takes one method.

	OpenTelemetry	DogStatsD	JSONL	Console
Sends to	your OpenTelemetry SDK	the Datadog Agent or Telegraf	a .jsonl file	standard error
Use it when	monitoring in production	monitoring with Datadog or InfluxDB	investigating a plan, the viewer	debugging locally
Per query	a span, plus per-node metrics	per-node metrics with tags	both plans and every counter	a dozen lines of text
Your data	in span attributes	none	in the file, which stays local	on your terminal
Cost	~0.1–2.4 ms, ~9 µs per value	~0.1–1 ms, buffered	~0.1–0.4 ms, 2–25 KB	negligible
When it fails	disabled after 5 errors	lost silently over UDP	first error logged, keeps trying	disabled after 5 errors

With no exporter argument, install() uses OpenTelemetry.

Several at once

exporter takes a list. Each exporter receives every query:

import polars_telemetry
from polars_telemetry import Config
from polars_telemetry.export.file import FileExporter
from polars_telemetry.export.otel import OTelExporter

config = Config()
polars_telemetry.install(
    config,
    exporter=[OTelExporter(config), FileExporter("profiles/session.jsonl")],
)

Failures stay contained

Exporters run on the thread that ran the query, after it has finished. An exporter that raises never fails the query: the error is logged once, and after five errors that exporter stops receiving queries while the others carry on.

polars-telemetry: disabling exporter ConsoleExporter after 5 errors. Queries are unaffected.