headroom/tests/test_proxy_pipeline_lifecycle.py
Rod Boev da2d8dc9db
fix(proxy): cancel retry backoff on shutdown (#1834)
## Description

During proxy shutdown, an in-flight retrying request can currently stay
asleep inside `_retry_request()` and keep the client socket hanging
until the retry timer expires or an external supervisor kills the
process. This wires retry backoff to a proxy-scoped shutdown event so
shutdown interrupts those waits immediately and returns a clear `503`
response instead of leaving the request stalled. Closes #1821.

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- Added a proxy-scoped shutdown event in `headroom/proxy/server.py`.
- Cleared that event at startup and set it at shutdown before teardown
proceeds.
- Replaced both retry-backoff sleeps with a helper that wakes on either
timeout or shutdown.
- Returned a shutdown `503` with `retry-after: 0` when shutdown
interrupts retry backoff.
- Stopped the shutdown interruption logs from falling back to the raw
upstream URL when no safe path string is available.
- Added focused regressions for retry-backoff interruption and shutdown
event signaling.
- Updated the existing Retry-After tests to observe the new
shutdown-aware wait helper instead of the old raw sleep hook.

## Testing

- [x] Unit tests pass (`uv run pytest
tests/test_proxy_handler_helpers.py
tests/test_proxy_pipeline_lifecycle.py -q`)
- [x] Unit tests pass (`uv run pytest tests/test_proxy_retry_429.py -q`)
- [x] Linting passes (`uv run ruff check headroom/proxy/server.py
tests/test_proxy_handler_helpers.py tests/test_proxy_retry_429.py
tests/test_proxy_pipeline_lifecycle.py`)
- [ ] Type checking passes (`uv run mypy headroom`)
- [x] New tests added for new functionality when applicable
- [ ] Manual testing performed

### Test Output

```text
uv run pytest tests/test_proxy_handler_helpers.py tests/test_proxy_pipeline_lifecycle.py -q
32 passed, 1 warning in 13.05s

uv run pytest tests/test_proxy_retry_429.py -q
10 passed, 1 warning in 1.12s

uv run ruff check headroom/proxy/server.py tests/test_proxy_handler_helpers.py tests/test_proxy_retry_429.py tests/test_proxy_pipeline_lifecycle.py
All checks passed!
```

## Real Behavior Proof

- Environment: Windows, project `uv` environment, focused proxy retry
and shutdown regressions.
- Exact command / steps: copy the updated shutdown regression files into
a detached `origin/main` worktree and run
`tests/test_proxy_handler_helpers.py` plus
`tests/test_proxy_pipeline_lifecycle.py`, then rerun those files on this
branch and separately rerun `tests/test_proxy_retry_429.py` after
updating the existing Retry-After tests to patch the shutdown-aware wait
helper.
- Observed result: base fails because retry backoff still returns the
original `429` and `shutdown()` leaves the retry event unset; head
passes the focused file, preserves the existing Retry-After assertions,
and returns a shutdown `503` with `retry-after: 0` while signaling retry
waiters during shutdown.
- Not tested: live systemd-managed shutdown on Linux or a full VS Code /
Claude Code session.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [x] I have updated the CHANGELOG.md if applicable

## Additional Notes

This is intentionally scoped to retry backoff during shutdown. It does
not try to cancel unrelated in-flight request work or change the broader
retry policy outside shutdown.
2026-07-06 06:24:47 -07:00

301 lines
10 KiB
Python

from __future__ import annotations
import asyncio
from types import SimpleNamespace
from unittest.mock import AsyncMock, Mock, call, patch
import httpx
from fastapi.testclient import TestClient
from headroom.pipeline import PipelineStage
from headroom.proxy.server import ProxyConfig, create_app
class _RecordingExtension:
def __init__(self) -> None:
self.stages: list[PipelineStage] = []
self.events: list = []
def on_pipeline_event(self, event):
self.stages.append(event.stage)
self.events.append(event)
return None
class _DummyTokenizer:
def count_messages(self, messages):
return len(messages)
def _assert_compressed_event_carries_originals(events: list) -> None:
"""INPUT_COMPRESSED must expose the pre-compression messages to extensions.
The probe recorder (headroom.proxy.probe_recorder) depends on this
metadata contract; dropping it silently disables session recording.
"""
compressed = [event for event in events if event.stage is PipelineStage.INPUT_COMPRESSED]
assert compressed
original = compressed[0].metadata.get("original_messages")
assert isinstance(original, list)
assert any(
message.get("role") == "user" and "hello" in str(message.get("content"))
for message in original
if isinstance(message, dict)
)
def _assert_stage_order(stages: list[PipelineStage]) -> None:
expected = [
PipelineStage.SETUP,
PipelineStage.PRE_START,
PipelineStage.POST_START,
PipelineStage.INPUT_RECEIVED,
PipelineStage.INPUT_ROUTED,
PipelineStage.INPUT_COMPRESSED,
PipelineStage.INPUT_REMEMBERED,
PipelineStage.PRE_SEND,
PipelineStage.POST_SEND,
PipelineStage.RESPONSE_RECEIVED,
]
positions = [stages.index(stage) for stage in expected]
assert positions == sorted(positions)
def test_proxy_shutdown_unloads_image_models() -> None:
config = ProxyConfig(
optimize=False,
image_optimize=False,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
)
app = create_app(config)
proxy = app.state.proxy
proxy.http_client = None
proxy.memory_handler = None
quota_registry = SimpleNamespace(stop_all=AsyncMock())
with (
patch("headroom.proxy.server.get_quota_registry", return_value=quota_registry),
patch("headroom.models.ml_models.MLModelRegistry.unload_prefix") as unload_prefix,
):
asyncio.run(proxy.shutdown())
assert unload_prefix.call_args_list == [
call("technique_router:"),
call("siglip:"),
]
quota_registry.stop_all.assert_awaited_once()
def test_proxy_shutdown_flushes_savings_tracker() -> None:
"""Graceful shutdown must flush the savings tracker's batched tail.
The proxy throttles savings persistence (save_flush_every=25), so buffered
requests only reach disk on the next threshold write or an explicit flush.
shutdown() is that flush; if the wiring regresses, a graceful stop silently
drops the last few requests' lifetime totals. The tracker's flush() logic is
covered in test_proxy_savings_history.py — this guards only the call site.
"""
config = ProxyConfig(
optimize=False,
image_optimize=False,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
)
app = create_app(config)
proxy = app.state.proxy
proxy.http_client = None
proxy.memory_handler = None
proxy.metrics.savings_tracker.flush = Mock()
quota_registry = SimpleNamespace(stop_all=AsyncMock())
with (
patch("headroom.proxy.server.get_quota_registry", return_value=quota_registry),
patch("headroom.models.ml_models.MLModelRegistry.unload_prefix"),
):
asyncio.run(proxy.shutdown())
proxy.metrics.savings_tracker.flush.assert_called_once()
def test_proxy_shutdown_signals_retry_waiters() -> None:
config = ProxyConfig(
optimize=False,
image_optimize=False,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
)
app = create_app(config)
proxy = app.state.proxy
proxy.http_client = None
proxy.memory_handler = None
proxy._shutdown_event = asyncio.Event()
quota_registry = SimpleNamespace(stop_all=AsyncMock())
with (
patch("headroom.proxy.server.get_quota_registry", return_value=quota_registry),
patch("headroom.models.ml_models.MLModelRegistry.unload_prefix"),
):
asyncio.run(proxy.shutdown())
assert proxy._shutdown_event.is_set()
def test_openai_chat_pipeline_events_cover_proxy_lifecycle(monkeypatch) -> None:
recorder = _RecordingExtension()
config = ProxyConfig(
optimize=True,
image_optimize=False,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
pipeline_extensions=[recorder],
discover_pipeline_extensions=False,
)
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
proxy.openai_pipeline = SimpleNamespace(
apply=lambda messages, model, **kwargs: SimpleNamespace(
messages=[
{"role": "system", "content": "memory"},
{"role": "user", "content": "hello"},
],
transforms_applied=["router:text:kompress"],
tokens_before=10,
tokens_after=6,
)
)
proxy.memory_handler = SimpleNamespace(
config=SimpleNamespace(inject_context=True, inject_tools=False),
search_and_format_context=AsyncMock(return_value="memory"),
has_memory_tool_calls=lambda response, provider: False,
)
monkeypatch.setattr("headroom.tokenizers.get_tokenizer", lambda model: _DummyTokenizer())
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
return httpx.Response(
200,
json={
"id": "chatcmpl_1",
"object": "chat.completion",
"choices": [{"message": {"role": "assistant", "content": "ok"}}],
"usage": {"prompt_tokens": 10, "completion_tokens": 3, "total_tokens": 13},
},
)
proxy._retry_request = _fake_retry
response = client.post(
"/v1/chat/completions",
headers={"Authorization": "Bearer sk-test", "x-headroom-user-id": "user-1"},
json={
"model": "gpt-5.4",
"messages": [{"role": "user", "content": "hello"}],
"tools": [{"type": "function", "function": {"name": "tool_a"}}],
},
)
assert response.status_code == 200
_assert_stage_order(recorder.stages)
_assert_compressed_event_carries_originals(recorder.events)
def test_anthropic_messages_pipeline_events_cover_proxy_lifecycle(monkeypatch) -> None:
recorder = _RecordingExtension()
config = ProxyConfig(
optimize=True,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
image_optimize=False,
pipeline_extensions=[recorder],
discover_pipeline_extensions=False,
)
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
proxy.anthropic_pipeline = SimpleNamespace(
apply=lambda messages, model, **kwargs: SimpleNamespace(
messages=[
{"role": "system", "content": "memory"},
{"role": "user", "content": "hello"},
],
transforms_applied=["router:text:kompress"],
tokens_before=10,
tokens_after=6,
)
)
proxy.memory_handler = SimpleNamespace(
config=SimpleNamespace(inject_context=True, inject_tools=False),
search_and_format_context=AsyncMock(return_value="memory"),
has_memory_tool_calls=lambda response, provider: False,
)
monkeypatch.setattr("headroom.tokenizers.get_tokenizer", lambda model: _DummyTokenizer())
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
return httpx.Response(
200,
json={
"id": "msg_1",
"type": "message",
"role": "assistant",
"content": [{"type": "text", "text": "ok"}],
"usage": {
"input_tokens": 10,
"output_tokens": 3,
"cache_read_input_tokens": 0,
"cache_creation_input_tokens": 0,
},
},
)
proxy._retry_request = _fake_retry
response = client.post(
"/v1/messages",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"x-headroom-user-id": "user-1",
},
json={
"model": "claude-sonnet-4-6",
"max_tokens": 128,
"messages": [{"role": "user", "content": "hello"}],
"tools": [
{"name": "tool_a", "description": "a", "input_schema": {"type": "object"}}
],
},
)
assert response.status_code == 200
_assert_stage_order(recorder.stages)
_assert_compressed_event_carries_originals(recorder.events)