diff --git a/litellm/scheduler.py b/litellm/scheduler.py index 73196d24e4d..c8cca47f6ae 100644 --- a/litellm/scheduler.py +++ b/litellm/scheduler.py @@ -1,15 +1,29 @@ import asyncio import enum import heapq +import logging as _logging +import random as _random import time from collections.abc import Awaitable, Callable, Sequence +from functools import partial as _partial from typing import Final, TypeAlias +from typing import Protocol as _Protocol from pydantic import TypeAdapter from litellm import print_verbose from litellm._internal_context import with_service_target +from litellm._logging import verbose_router_logger as _verbose_router_logger from litellm.caching.caching import DualCache, RedisCache +from litellm.caching.redis_cache import ( + RedisCircuitBreakerOpenError as _RedisCircuitBreakerOpenError, +) +from litellm.caching.redis_cache import ( + _is_redis_health_failure, # pyright: ignore[reportPrivateUsage] # RedisCache's connectivity classifier has no public counterpart +) +from litellm.caching.redis_cache import ( + log_redis_failure as _log_redis_failure, +) from litellm.constants import DEFAULT_IN_MEMORY_TTL, DEFAULT_POLLING_INTERVAL from litellm.exceptions import Timeout from litellm.types.llms.base import LiteLLMBaseModel @@ -17,6 +31,25 @@ from litellm.types.llms.base import LiteLLMBaseModel SCHEDULER_QUEUE_TARGET: Final = "scheduler_queue" QueueEntry: TypeAlias = tuple[int, str] _QUEUE_ENTRIES: Final = TypeAdapter(list[QueueEntry]) +_Queue: TypeAlias = tuple[QueueEntry, ...] +_QueueResult: TypeAlias = tuple[bool, _Queue] +_QUEUE_SNAPSHOT: Final = TypeAdapter(_Queue) +_RAW_QUEUE: Final = TypeAdapter[str | bytes | None](str | bytes | None) +_CAS_RESULT: Final = TypeAdapter(bool) +_QUEUE_READ: Final = "return redis.call('GET', KEYS[1])" +_QUEUE_COMPARE_SET: Final = """ +local current = redis.call('GET', KEYS[1]) +if (ARGV[1] == '0' and current ~= false) or + (ARGV[1] == '1' and current ~= ARGV[2]) then + return 0 +end +if ARGV[4] == '' then + redis.call('SET', KEYS[1], ARGV[3]) +else + redis.call('SET', KEYS[1], ARGV[3], 'EX', ARGV[4]) +end +return 1 +""" class SchedulerCacheKeys(enum.Enum): @@ -30,6 +63,98 @@ class FlowItem(LiteLLMBaseModel): model_name: str +class _LocalQueueCache(_Protocol): + @property + def default_in_memory_ttl(self) -> float | None: ... + + async def async_get_cache(self, key: str, *, local_only: bool) -> object: ... + + async def async_set_cache(self, key: str, value: Sequence[QueueEntry], *, local_only: bool) -> None: ... + + +async def _read_local_queue(cache: _LocalQueueCache, key: str) -> _Queue: + local: Final = await cache.async_get_cache(key=key, local_only=True) + return _QUEUE_SNAPSHOT.validate_python(local or ()) + + +async def _write_local_queue(cache: _LocalQueueCache, key: str, queue: _Queue) -> None: + await cache.async_set_cache(key=key, value=list(queue), local_only=True) + + +def _enqueue(entry: QueueEntry, queue: _Queue) -> _QueueResult: + return False, queue if entry in queue else tuple(sorted((*queue, entry))) + + +def _remove(request_id: str, queue: _Queue) -> _QueueResult: + return False, tuple(sorted(item for item in queue if item[1] != request_id)) + + +def _poll(entry: QueueEntry, queue: _Queue) -> _QueueResult: + pending: Final = tuple(sorted(queue if entry in queue else (*queue, entry))) + return (True, pending[1:]) if pending[0] == entry else (False, pending) + + +def _redis_unavailable(error: Exception) -> bool: + return isinstance(error, _RedisCircuitBreakerOpenError) or _is_redis_health_failure(error) + + +async def _read_redis_queue(cache: RedisCache, key: str) -> tuple[str | bytes | None, _Queue]: + raw: Final = _RAW_QUEUE.validate_python(await cache.async_register_script(_QUEUE_READ)(keys=(key,), args=())) + return raw, () if raw is None else _QUEUE_SNAPSHOT.validate_json(raw) + + +async def _mutate_redis_queue( + cache: RedisCache, key: str, model_name: str, ttl: int | None, change: Callable[[_Queue], _QueueResult] +) -> _QueueResult: + script: Final = cache.async_register_script(_QUEUE_COMPARE_SET) + for attempt in range(100): + raw, queue = await _read_redis_queue(cache, key) + admitted, updated = change(queue) + if updated == queue: + return admitted, updated + if _CAS_RESULT.validate_python( + await script( + keys=(key,), + args=( + "0" if raw is None else "1", + raw or "", + _QUEUE_SNAPSHOT.dump_json(updated), + "" if ttl is None else str(ttl), + ), + ) + ): + return admitted, updated + if attempt < 99: + await asyncio.sleep(_random.uniform(0, min(0.05, 0.001 * 2 ** min(attempt, 6)))) + raise Timeout( + message="Scheduler queue remained busy after concurrent updates", model=model_name, llm_provider="openai" + ) + + +async def _shared_queue_result( + cache: _LocalQueueCache, + redis_cache: RedisCache, + key: str, + model_name: str, + change: Callable[[_Queue], _QueueResult], +) -> _QueueResult: + try: + return await _mutate_redis_queue( + redis_cache, + key, + model_name, + redis_cache.default_ttl if cache.default_in_memory_ttl is None else int(cache.default_in_memory_ttl), + change, + ) + except Exception as error: + if not _redis_unavailable(error): + raise + _log_redis_failure( + _verbose_router_logger, _logging.WARNING, "Scheduler using local queue while Redis is unavailable", error + ) + return change(await _read_local_queue(cache, key)) + + class Scheduler: cache: DualCache @@ -49,7 +174,22 @@ class Scheduler: self.cache = DualCache(redis_cache=redis_cache, default_in_memory_ttl=default_in_memory_ttl) self.polling_interval = polling_interval or DEFAULT_POLLING_INTERVAL # default to 3ms + @with_service_target(SCHEDULER_QUEUE_TARGET) + async def _update_shared_queue( + self, redis_cache: RedisCache, model_name: str, change: Callable[[_Queue], _QueueResult] + ) -> bool: + key: Final = f"{SchedulerCacheKeys.queue.value}:{model_name}" + result: Final = await _shared_queue_result(self.cache, redis_cache, key, model_name, change) + await _write_local_queue(self.cache, key, result[1]) + return result[0] + async def add_request(self, request: FlowItem): + redis_cache: Final = self.cache.redis_cache + if isinstance(redis_cache, RedisCache): + await self._update_shared_queue( + redis_cache, request.model_name, _partial(_enqueue, (request.priority, request.request_id)) + ) + return # We use the priority directly, as lower values indicate higher priority # get the queue queue: Final = await self.get_queue(model_name=request.model_name) @@ -78,6 +218,11 @@ class Scheduler: if len(health_deployments) > 0: return True + redis_cache: Final = self.cache.redis_cache + if isinstance(redis_cache, RedisCache): + return await self._update_shared_queue( + redis_cache, request.model_name, _partial(_poll, (request.priority, request.request_id)) + ) queue: Final = await self.get_queue(model_name=request.model_name) entry: Final = (request.priority, request.request_id) print_verbose(f"queue: {queue}, seeking {entry}") @@ -109,14 +254,24 @@ class Scheduler: return await asyncio.sleep(self.polling_interval) finally: - await asyncio.shield(self.remove_request(request_id=request.request_id, model_name=request.model_name)) + await asyncio.shield(self._cleanup_request(request)) raise Timeout(message="Request timed out while polling queue", model=request.model_name, llm_provider="openai") + async def _cleanup_request(self, request: FlowItem) -> None: + try: + await self.remove_request(request_id=request.request_id, model_name=request.model_name) + except Exception as error: # noqa: BLE001 # Cleanup must preserve every request outcome, including cancellation + _log_redis_failure(_verbose_router_logger, _logging.WARNING, "Scheduler queue cleanup failed", error) + async def remove_request(self, request_id: str, model_name: str) -> None: """ Remove a specific request from the priority queue for a model. Used when a request times out while waiting in the queue. """ + redis_cache: Final = self.cache.redis_cache + if isinstance(redis_cache, RedisCache): + await self._update_shared_queue(redis_cache, model_name, _partial(_remove, request_id)) + return queue: Final = await self.get_queue(model_name=model_name) filtered_queue: Final = [item for item in queue if item[1] != request_id] heapq.heapify(filtered_queue) # restore heap invariant after filtering @@ -151,6 +306,17 @@ class Scheduler: Redis hands the queue back as JSON lists, so every entry is validated into the (priority, request_id) tuple the heap operations compare against. """ + redis_cache: Final = self.cache.redis_cache + if isinstance(redis_cache, RedisCache): + key: Final = f"{SchedulerCacheKeys.queue.value}:{model_name}" + try: + _, snapshot = await _read_redis_queue(redis_cache, key) + except Exception as error: + if not _redis_unavailable(error): + raise + return list(await _read_local_queue(self.cache, key)) + await _write_local_queue(self.cache, key, snapshot) + return list(snapshot) if self.cache is not None: _cache_key: Final = f"{SchedulerCacheKeys.queue.value}:{model_name}" response: Final = await self.cache.async_get_cache(key=_cache_key) diff --git a/tests/integration/sdk/test_dual_cache_redis.py b/tests/integration/sdk/test_dual_cache_redis.py index 3527dbf91ee..98d5aac097b 100644 --- a/tests/integration/sdk/test_dual_cache_redis.py +++ b/tests/integration/sdk/test_dual_cache_redis.py @@ -1,15 +1,22 @@ import asyncio import os +import threading import uuid -from typing import Final +from collections.abc import AsyncIterator, Iterator +from typing import Final, Literal from unittest.mock import patch import pytest +import pytest_asyncio +from integration._support.async_server import LoopbackServer, close_writer +from integration._support.ports import allocate_port +from pydantic import ValidationError from litellm.caching.affinity_cache import claim_affinity_pin from litellm.caching.dual_cache import DualCache from litellm.caching.in_memory_cache import InMemoryCache from litellm.caching.redis_cache import RedisCache +from litellm.scheduler import FlowItem, Scheduler, SchedulerCacheKeys def _redis_cache() -> RedisCache: @@ -95,6 +102,212 @@ async def test_sync_and_async_batch_reads_share_one_redis_without_sync_reads_goi assert await dual_cache.async_batch_get_cache(keys=[survivor_key]) == [expected[survivor_key]] +@pytest_asyncio.fixture(loop_scope="function") +async def shared_scheduler_cache() -> AsyncIterator[RedisCache]: + cache: Final = RedisCache( + host=os.environ["REDIS_HOST"], + port=int(os.environ["REDIS_PORT"]), + namespace="scheduler-atomic-" + uuid.uuid4().hex, + ) + try: + yield cache + finally: + client: Final = cache.init_async_client() + await client.delete(cache.check_and_fix_namespace(f"{SchedulerCacheKeys.queue.value}:shared")) + await client.aclose() + cache.redis_client.close() + + +async def test_shared_scheduler_preserves_concurrent_admissions(shared_scheduler_cache: RedisCache) -> None: + first: Final = Scheduler(redis_cache=shared_scheduler_cache) + second: Final = Scheduler(redis_cache=shared_scheduler_cache) + await asyncio.gather(first.get_queue("shared"), second.get_queue("shared")) + await asyncio.gather( + first.add_request(FlowItem(priority=1, request_id="first", model_name="shared")), + second.add_request(FlowItem(priority=2, request_id="second", model_name="shared")), + ) + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == [[1, "first"], [2, "second"]] + assert await first.get_queue("shared") == [(1, "first"), (2, "second")] + assert await second.get_queue("shared") == [(1, "first"), (2, "second")] + + +async def test_shared_scheduler_does_not_resurrect_peer_removal(shared_scheduler_cache: RedisCache) -> None: + await shared_scheduler_cache.async_set_cache("scheduler:queue:shared", [[1, "removed"], [2, "waiting"]]) + first: Final = Scheduler(redis_cache=shared_scheduler_cache) + second: Final = Scheduler(redis_cache=shared_scheduler_cache) + await asyncio.gather(first.get_queue("shared"), second.get_queue("shared")) + await first.remove_request("removed", "shared") + await second.add_request(FlowItem(priority=3, request_id="new", model_name="shared")) + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == [[2, "waiting"], [3, "new"]] + + +async def test_shared_scheduler_observes_peer_pop(shared_scheduler_cache: RedisCache) -> None: + await shared_scheduler_cache.async_set_cache("scheduler:queue:shared", [[1, "first"], [2, "second"]]) + first: Final = Scheduler(redis_cache=shared_scheduler_cache) + second: Final = Scheduler(redis_cache=shared_scheduler_cache) + await asyncio.gather(first.get_queue("shared"), second.get_queue("shared")) + assert await first.poll(FlowItem(priority=1, request_id="first", model_name="shared"), []) + assert await second.poll(FlowItem(priority=2, request_id="second", model_name="shared"), []) + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == [] + + +async def test_shared_scheduler_keeps_other_requests_during_concurrent_cleanup( + shared_scheduler_cache: RedisCache, +) -> None: + schedulers: Final = tuple(Scheduler(redis_cache=shared_scheduler_cache) for _ in range(16)) + await asyncio.gather( + *( + scheduler.add_request(FlowItem(priority=i, request_id=str(i), model_name="shared")) + for i, scheduler in enumerate(schedulers) + ) + ) + await asyncio.gather( + *(scheduler.remove_request(str(i), "shared") for i, scheduler in enumerate(schedulers) if i % 2 == 0) + ) + assert await schedulers[0].get_queue("shared") == [(i, str(i)) for i in range(16) if i % 2] + + +@pytest.fixture +def interrupted_scheduler_cache(shared_scheduler_cache: RedisCache) -> Iterator[tuple[RedisCache, threading.Event]]: + interrupted: Final = threading.Event() + + async def relay(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None: + upstream_reader, upstream_writer = await asyncio.open_connection( + os.environ["REDIS_HOST"], int(os.environ["REDIS_PORT"]) + ) + + async def forward(source: asyncio.StreamReader, destination: asyncio.StreamWriter) -> None: + try: + while chunk := await source.read(65536): + if interrupted.is_set(): + return + destination.write(chunk) + await destination.drain() + except ConnectionError: + return + finally: + await close_writer(destination) + + await asyncio.gather(forward(reader, upstream_writer), forward(upstream_reader, writer)) + + port: Final = allocate_port() + server: Final = LoopbackServer(port, relay) + server.start() + cache: Final = RedisCache(host="127.0.0.1", port=port, namespace=shared_scheduler_cache.namespace) + try: + yield cache, interrupted + finally: + cache.redis_client.close() + server.stop() + + +async def test_shared_scheduler_keeps_local_fallback_out_of_recovered_shared_queue( + shared_scheduler_cache: RedisCache, + interrupted_scheduler_cache: tuple[RedisCache, threading.Event], +) -> None: + cache, interrupted = interrupted_scheduler_cache + scheduler: Final = Scheduler(redis_cache=cache) + try: + await scheduler.add_request(FlowItem(priority=1, request_id="removed", model_name="shared")) + interrupted.set() + await scheduler.add_request(FlowItem(priority=2, request_id="local", model_name="shared")) + assert await scheduler.get_queue("shared") == [(1, "removed"), (2, "local")] + await Scheduler(redis_cache=shared_scheduler_cache).remove_request("removed", "shared") + interrupted.clear() + await scheduler.add_request(FlowItem(priority=3, request_id="new", model_name="shared")) + assert await scheduler.get_queue("shared") == [(3, "new")] + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == [[3, "new"]] + finally: + interrupted.clear() + await cache.init_async_client().aclose() + + +async def test_shared_scheduler_preserves_invalid_queue_for_diagnosis(shared_scheduler_cache: RedisCache) -> None: + await shared_scheduler_cache.async_set_cache("scheduler:queue:shared", {"invalid": "queue"}) + scheduler: Final = Scheduler(redis_cache=shared_scheduler_cache) + with pytest.raises(ValidationError): + await scheduler.add_request(FlowItem(priority=1, request_id="first", model_name="shared")) + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == {"invalid": "queue"} + + +@pytest.mark.parametrize("priority", [0, -1, 2**80]) +async def test_shared_scheduler_retains_priority_and_request_id( + shared_scheduler_cache: RedisCache, priority: int +) -> None: + scheduler: Final = Scheduler(redis_cache=shared_scheduler_cache) + scheduler.cache.update_cache_ttl(default_in_memory_ttl=17, default_redis_ttl=None) + await scheduler.add_request(FlowItem(priority=priority, request_id="请求-é", model_name="shared")) + assert await scheduler.get_queue("shared") == [(priority, "请求-é")] + assert ( + 0 + < shared_scheduler_cache.redis_client.ttl( + shared_scheduler_cache.check_and_fix_namespace("scheduler:queue:shared") + ) + <= 17 + ) + + +@pytest.mark.parametrize("outcome", ["admitted", "failed", "cancelled"]) +async def test_shared_scheduler_cleanup_failure_preserves_request_outcome( + shared_scheduler_cache: RedisCache, + outcome: Literal["admitted", "failed", "cancelled"], + caplog: pytest.LogCaptureFixture, +) -> None: + scheduler: Final = Scheduler(redis_cache=shared_scheduler_cache) + original: Final = RuntimeError("health lookup failed") + + async def health_after_corrupting_queue() -> tuple[object, ...]: + await shared_scheduler_cache.async_set_cache("scheduler:queue:shared", {"invalid": "queue"}) + match outcome: + case "failed": + raise original + case "cancelled": + raise asyncio.CancelledError + case "admitted": + return ("healthy",) + + async def wait() -> None: + await scheduler.wait_for_turn( + FlowItem(priority=1, request_id="cleanup", model_name="shared"), + timeout=5, + get_healthy_deployments=health_after_corrupting_queue, + ) + + match outcome: + case "admitted": + await wait() + case "failed": + with pytest.raises(RuntimeError) as caught: + await wait() + assert caught.value is original + case "cancelled": + with pytest.raises(asyncio.CancelledError): + await wait() + assert "Scheduler queue cleanup failed" in caplog.text + assert await shared_scheduler_cache.async_get_cache("scheduler:queue:shared") == {"invalid": "queue"} + + +async def test_shared_scheduler_handles_three_hundred_concurrent_enqueues_and_removals( + shared_scheduler_cache: RedisCache, +) -> None: + schedulers: Final = tuple(Scheduler(redis_cache=shared_scheduler_cache) for _ in range(300)) + for scheduler in schedulers: + scheduler.cache.update_cache_ttl(default_in_memory_ttl=60, default_redis_ttl=None) + requests: Final = tuple( + FlowItem(priority=i % 8, request_id=f"burst-{i:03}", model_name="shared") for i in range(300) + ) + + await asyncio.gather(*(scheduler.add_request(request) for scheduler, request in zip(schedulers, requests))) + + assert await schedulers[0].get_queue("shared") == sorted( + (request.priority, request.request_id) for request in requests + ) + await asyncio.gather( + *(scheduler.remove_request(request.request_id, "shared") for scheduler, request in zip(schedulers, requests)) + ) + assert await schedulers[0].get_queue("shared") == [] + + @pytest.mark.asyncio async def test_concurrent_session_repin_claims_keep_the_shared_winner_after_recovery() -> None: redis: Final = _redis_cache() diff --git a/tests/unit/test_scheduler.py b/tests/unit/test_scheduler.py index e0968e9b2cf..6eeec6329ed 100644 --- a/tests/unit/test_scheduler.py +++ b/tests/unit/test_scheduler.py @@ -5,13 +5,18 @@ import asyncio import importlib import json import os -from collections.abc import Sequence -from typing import Final +from collections.abc import Iterator, Sequence +from typing import Final, Literal +from unittest.mock import AsyncMock, patch import pytest +from pydantic import ValidationError +from redis.exceptions import ConnectionError as RedisConnectionError import litellm from litellm.litellm_core_utils.logging_worker import GLOBAL_LOGGING_WORKER +from litellm.caching.redis_cache import RedisCache +from litellm.exceptions import Timeout from litellm.scheduler import FlowItem, Scheduler, SchedulerCacheKeys from litellm.utils import _invalidate_model_cost_lowercase_map from tests._vcr_conftest_common import install_live_call_probe, record_vcr_outcome @@ -332,6 +337,159 @@ async def test_wait_for_turn_finishes_removal_when_cancelled_again_during_cleanu assert await scheduler.get_queue("sched-model") == [(0, "head")] +@pytest.fixture +def scheduler_redis_replies() -> Iterator[tuple[RedisCache, AsyncMock, AsyncMock]]: + reads: Final = AsyncMock(return_value=None) + writes: Final = AsyncMock(return_value=1) + + async def execute( + *, keys: Sequence[str], args: Sequence[str | bytes | int | float], client: object = None + ) -> object: + return await (writes if args else reads)(keys=keys, args=args, client=client) + + with ( + patch("redis.Redis.execute_command", return_value={"redis_version": "unit-fixture"}), + patch("redis.asyncio.Redis.execute_command", new_callable=AsyncMock, return_value=True), + patch("redis.commands.core.AsyncScript.__call__", side_effect=execute), + ): + cache: Final = RedisCache(host="scheduler-unit.invalid", port=6379) + yield cache, reads, writes + cache.redis_client.close() + + +@pytest.mark.asyncio +async def test_shared_scheduler_retries_conflicts_using_the_new_peer_snapshot( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], +) -> None: + cache, reads, writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + reads.side_effect = (None, b'[[0,"peer"]]', RedisConnectionError("offline")) + writes.side_effect = (0, 1) + + await scheduler.add_request(FlowItem(priority=1, request_id="new", model_name="shared")) + + assert await scheduler.get_queue("shared") == [(0, "peer"), (1, "new")] + + +@pytest.mark.asyncio +async def test_shared_scheduler_stops_after_conflicts_without_publishing_an_uncommitted_queue( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], +) -> None: + cache, _reads, writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + writes.return_value = 0 + + with patch("random.uniform", return_value=0), pytest.raises(Timeout, match="queue remained busy"): + await scheduler.add_request(FlowItem(priority=1, request_id="never-committed", model_name="shared")) + + assert await scheduler.cache.async_get_cache("scheduler:queue:shared", local_only=True) is None + + +@pytest.mark.parametrize("operation", ["enqueue", "read"]) +@pytest.mark.asyncio +async def test_shared_scheduler_rejects_malformed_snapshots_without_replacing_local_history( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], operation: str +) -> None: + cache, reads, _writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + await scheduler.cache.async_set_cache("scheduler:queue:shared", [(0, "last-known")], local_only=True) + reads.side_effect = (b'{"invalid":"queue"}',) + + call: Final = ( + scheduler.add_request(FlowItem(priority=1, request_id="new", model_name="shared")) + if operation == "enqueue" + else scheduler.get_queue("shared") + ) + with pytest.raises(ValidationError): + await call + + assert await scheduler.cache.async_get_cache("scheduler:queue:shared", local_only=True) == [(0, "last-known")] + + +@pytest.mark.parametrize("outcome", ["admitted", "failed", "cancelled"]) +@pytest.mark.asyncio +async def test_shared_scheduler_cleanup_failure_preserves_the_request_outcome( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], outcome: Literal["admitted", "failed", "cancelled"] +) -> None: + cache, reads, _writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + original: Final = RuntimeError("health lookup failed") + reads.side_effect = (None, b'{"invalid":"queue"}') + + async def health() -> Sequence[object]: + match outcome: + case "failed": + raise original + case "cancelled": + raise asyncio.CancelledError + case "admitted": + return ("healthy",) + + async def wait() -> None: + await scheduler.wait_for_turn( + FlowItem(priority=1, request_id="waiting", model_name="shared"), timeout=5, get_healthy_deployments=health + ) + + match outcome: + case "admitted": + await wait() + case "failed": + with pytest.raises(RuntimeError) as caught: + await wait() + assert caught.value is original + case "cancelled": + with pytest.raises(asyncio.CancelledError): + await wait() + assert await scheduler.cache.async_get_cache("scheduler:queue:shared", local_only=True) == [(1, "waiting")] + + +@pytest.mark.asyncio +async def test_shared_scheduler_keeps_admission_and_removal_in_its_fallback_snapshot( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], +) -> None: + cache, reads, _writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + head: Final = FlowItem(priority=0, request_id="head", model_name="shared") + later: Final = FlowItem(priority=2, request_id="later", model_name="shared") + reads.side_effect = ( + b'[[0,"head"],[2,"later"]]', + b'[[0,"head"],[2,"later"]]', + b'[[0,"head"],[2,"later"]]', + RedisConnectionError("offline after admission"), + b'[[2,"later"],[3,"peer"]]', + RedisConnectionError("offline after removal"), + b'[[3,"peer"]]', + ) + + await scheduler.add_request(head) + assert not await scheduler.poll(later, []) + assert await scheduler.poll(head, []) + assert await scheduler.get_queue("shared") == [(2, "later")] + await scheduler.remove_request("later", "shared") + assert await scheduler.get_queue("shared") == [(3, "peer")] + assert await scheduler.get_queue("shared") == [(3, "peer")] + + +@pytest.mark.asyncio +async def test_shared_scheduler_does_not_upload_outage_only_requests_when_redis_recovers( + scheduler_redis_replies: tuple[RedisCache, AsyncMock, AsyncMock], +) -> None: + cache, reads, writes = scheduler_redis_replies + scheduler: Final = Scheduler(redis_cache=cache) + reads.side_effect = ( + RedisConnectionError("offline during enqueue"), + RedisConnectionError("still offline"), + b'[[0,"peer"]]', + RedisConnectionError("offline after recovery"), + ) + + await scheduler.add_request(FlowItem(priority=1, request_id="local-only", model_name="shared")) + assert await scheduler.get_queue("shared") == [(1, "local-only")] + await scheduler.add_request(FlowItem(priority=2, request_id="new", model_name="shared")) + assert await scheduler.get_queue("shared") == [(0, "peer"), (2, "new")] + assert json.loads(writes.call_args.kwargs["args"][2]) == [[0, "peer"], [2, "new"]] + + @pytest.fixture(autouse=True) def _vcr_outcome_gate(request, vcr): install_live_call_probe(request, vcr)