Prasad Subrahmanya 1fc77f995b fix(agent): fall back on rate limit when pool has no rotation room ...

Extracts pool-rotation-room logic into `_pool_may_recover_from_rate_limit`
so single-credential pools no longer block the eager-fallback path on 429.

The existing check `pool is not None and pool.has_available()` lets
fallback fire only after the pool marks every entry as exhausted.  With
exactly one credential in the pool (the common shape for Gemini OAuth,
Vertex service accounts, and any personal-key setup), `has_available()`
flips back to True as soon as the cooldown expires — Hermes retries
against the same entry, hits the same daily-quota 429, and burns the
retry budget in a tight loop before ever reaching the configured
`fallback_model`.  Observed in the wild as 4+ hours of 429 noise on a
single Gemini key instead of falling through to Vertex as configured.

Rotation is only meaningful with more than one credential — gate on
`len(pool.entries()) > 1`.  Multi-credential pools keep the current
wait-for-rotation behaviour unchanged.

Fixes #11314.  Related to #8947, #10210, #7230.  Narrower scope than
open PRs #8023 (classifier change) and #11492 (503/529 credential-pool
bypass) — this addresses the single-credential 429 case specifically
and does not conflict with either.

Tests: 6 new unit tests in tests/run_agent/test_provider_fallback.py
covering (a) None pool, (b) single-cred available, (c) single-cred in
cooldown, (d) 2-cred available rotates, (e) multi-cred all cooling-down
falls back, (f) many-cred available rotates.  All 18 tests in the file
pass.

2026-04-24 05:20:05 -07:00

8.6 KiB

Raw Blame History

View Raw