[Idea] Migrate from backoff to backon (drop-in replacement, zero deps, upstream archived)

[Llucs]

Summary

backon is a modern evolution of the backoff library that Superset currently depends on (backoff>=1.8.0). It is a near-drop-in replacement with zero dependencies, active maintenance, and full Python 3.14+ compatibility.

Motivation

1. Upstream backoff is archived

The original litl/backoff library was archived in August 2025. It uses asyncio.iscoroutinefunction() which was deprecated in Python 3.14 and removed in Python 3.16. While the python-backoff fork exists, it adds an extra transitive dependency for Superset users.

2. Python 3.14+ compatibility

Python 3.14 is approaching and backoff will need patches to work with it. backon was designed from the ground up with modern Python in mind (requires 3.9+).

3. Zero dependencies

backon is pure Python with stdlib only, no runtime dependencies. This removes the backoff transitive dependency from Superset's dependency tree entirely.

4. Richer feature set (optional)

If desired in the future, backon offers circuit breaker, hedging, context manager API, global toggle for testing, custom sleep injection, Prometheus/OTel metrics, and more, all without adding any required dependencies.

Migration path

Migration is a straightforward import change, the public API is identical:

- import backoff
+ import backon

- @backoff.on_exception(backoff.expo, ValueError, max_tries=3)
+ @backon.on_exception(backon.expo, ValueError, max_tries=3)

All backoff names (expo, fibo, constant, runtime, on_exception, on_predicate, full_jitter, random_jitter) exist in backon with the same signatures.

Comparison

Area	backoff	backon
Python support	3.7+	3.9+
Dependencies	0	0
Maintenance	Archived (Aug 2025)	Active (112+ commits, Jul 2026)
Type hints	Partial	Full
Circuit breaker	Not supported	Supported
Hedging	Not supported	Supported
Context manager	Not supported	Retrying class
Global toggle	Not supported	disable()/enable()
Testing utilities	Not supported	remove_backoff(), assert_retried(), etc.

Would the team be open to evaluating this migration?

I am happy to submit a PR if there is interest.

[rusackas]

Looks like it works with Python 3.11, which is our minimum. No objection from me if you want to open a PR. @hainenber may be interested in this too.

[hainenber]

+1 from me too 👍

[Llucs]

Looks like it works with Python 3.11, which is our minimum. No objection from me if you want to open a PR. @hainenber may be interested in this too.

Done! The pull request is open at #42361