Lab: Retry-After, backoff and jitter¶

One script against clientwright's in-process origin.

uv venv --python 3.13 .venv
uv pip install --python .venv/bin/python "clientwright[httpx]==0.2.2"
.venv/bin/python backoff_lab.py

Four scenes: a 503 with a Retry-After header, honoured and ignored; fifty callers retrying at once with and without jitter, and when their retries land; a POST that timed out on read, with and without being declared idempotent, and how many times the origin received it; and which outcomes and methods are retried by default.