litellm-e2e-ui 68 failed the test this PR was meant to stabilise: "fallback
never took effect", streak 4 of a required 5, 60s timeout. Requiring a
consecutive streak of 200s after the fallback is set was wrong. It asserts that
the fallback path succeeds five times running, which is a reliability claim the
test never intended to make, and the path is inherently retry-ish because the
broken primary is attempted first on every call. One intermittent non-200
resets the streak, so a mostly-working fallback never converges.
The two directions are not symmetric:
before the write proving NO replica serves it -> needs every replica
after the write proving the fallback serves it -> one success is the claim
So the control keeps a multi-sample window and the success assertion goes back
to polling for a first sighting, on the wider 60s budget rather than the
original 30s that expired on litellm-e2e-ui 63.
Also drops the two local rebinds Greptile flagged against the repo's
no-reassignment convention: the streak counter is gone with the helper it lived
in, and the cache-round loop is now a lazy generator consumed by next().
(cherry picked from commit b95801172c)
a2aecfea7f