Daoyuan Li 79611673d7

Fix circuit breaker wedging after a non-retriable half-open probe (#3991) ...

* Fix circuit breaker wedging after a non-retriable half-open probe

When the circuit breaker is half-open it admits a single probe call by
setting `_circuit_probe_in_flight = True`. If that probe raised a
*non-retriable* error (e.g. quota/auth), the except block skipped both
`_record_failure()` (correct - business errors must not trip the breaker)
and any probe reset, so the circuit stayed `half_open` with
`_circuit_probe_in_flight = True` permanently. Every later call then
fast-failed in `_check_circuit()` forever, because no call could run the
handler to reach `_record_success` / `_record_failure`.

Release the probe on the non-retriable path (mirroring the existing
GraphBubbleUp handler) so the next call admits a fresh probe. The breaker
still never trips on non-retriable errors. Applied to both the sync and
async paths.

Adds sync + async regression tests asserting the probe is released and the
next `_check_circuit()` re-admits a probe.

* Address review: extract _release_half_open_probe helper

2026-07-11 07:54:15 +08:00

..

harness

Fix circuit breaker wedging after a non-retriable half-open probe (#3991)

2026-07-11 07:54:15 +08:00