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polars-telemetry

Telemetry for Polars queries: a span per query with its plan and per-node metrics for OpenTelemetry, or profiles you open in a browser-based viewer.

Unaffiliated with Polars and Polars Cloud

This package attaches to an interface polars exposes for its own cloud product. That interface is internal and carries no deprecation guarantee, so it can change or disappear in any polars release. See Compatibility for what happens when it does.

Note

This site tracks main, so it can describe work that is not released yet. The changelog says what shipped.

pip install 'polars-telemetry[otlp]'

import polars_telemetry

polars_telemetry.install()

Both plans, per-node counters and diagnostics for one query

What you get

For every query polars runs:

  • how long it took, how much CPU it used, and how well it spread across cores
  • both plans: scans and their pushed-down filters, joins, group-by keys
  • every node's counters: rows, morsels, polls, IO time and bytes
  • the most expensive node, and diagnostics such as filter selectivity and join fan-out
  • the file, line and function that ran it, and your own label

Where to start

You want to… Read
Try it in two minutes Getting started
Choose where queries go Exporters
See inside one slow query JSONL and the viewer
Monitor queries in production OpenTelemetry
Know what leaves your process Data and privacy
Look up an attribute Spans and metrics