fix(router): preserve discovered limits and model info fallbacks

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
This commit is contained in:
Moe Khalil 2026-09-17 00:23:50 +00:00
parent d0ed8145b0
commit bab273ea0f
4 changed files with 153 additions and 17 deletions

View file

@ -9324,12 +9324,6 @@ def get_litellm_model_info(model: dict = {}):
model_info: Final = model.get("model_info", {})
model_to_lookup = model.get("litellm_params", {}).get("model", None)
try:
if llm_router is not None and model_info.get("id") is not None:
deployment_info: Final = llm_router.get_deployment_model_info(
model_id=model_info["id"], model_name=model_to_lookup
)
if deployment_info is not None:
return deployment_info
if "azure" in model_to_lookup or model_info.get("base_model"):
model_to_lookup = model_info.get("base_model", None)
litellm_model_info: Final = litellm.get_model_info(model_to_lookup)
@ -13623,8 +13617,11 @@ def _enrich_model_info_with_litellm_data(
litellm_model_info = litellm.get_model_info(model=litellm_model, custom_llm_provider=split_model[0])
except Exception:
litellm_model_info = {}
for k, v in litellm_model_info.items():
if model_info.get(k) is None:
discovered_model_info: Final = (
llm_router.get_discovered_model_info(model_info.get("id")) if llm_router is not None else MappingProxyType({})
)
for k, v in MappingProxyType({**litellm_model_info, **discovered_model_info}).items():
if k not in model_info or (model_info[k] is None and k in discovered_model_info):
model_info[k] = v
model["model_info"] = model_info
# don't return the api key / vertex credentials
@ -15089,8 +15086,11 @@ def _get_proxy_model_info(model: dict) -> dict:
litellm_model_info = litellm.get_model_info(model=litellm_model, custom_llm_provider=split_model[0])
except Exception:
litellm_model_info = {}
for k, v in litellm_model_info.items():
if k not in model_info:
discovered_model_info: Final = (
llm_router.get_discovered_model_info(model_info.get("id")) if llm_router is not None else MappingProxyType({})
)
for k, v in MappingProxyType({**litellm_model_info, **discovered_model_info}).items():
if k not in model_info or (model_info[k] is None and k in discovered_model_info):
model_info[k] = v
model["model_info"] = model_info
# don't return the llm credentials

View file

@ -982,7 +982,7 @@ class Router:
self.get_deployment_model_info
)
self._discovered_model_info_cache: InMemoryCache = InMemoryCache(
max_size_in_memory=DEFAULT_MAX_LRU_CACHE_SIZE,
max_size_in_memory=max(len(model_list or ()), 1),
default_ttl=2 * MODEL_INFO_REFRESH_SECONDS,
)
self._routing_group_rows: tuple[DeploymentTypedDict, ...] | None = None
@ -9504,6 +9504,7 @@ class Router:
def set_model_list(self, model_list: list):
original_model_list: Final = copy.deepcopy(model_list)
self._discovered_model_info_cache.flush_cache()
self.model_list = []
self.model_id_to_deployment_index_map = {} # Reset the index
self.model_name_to_deployment_indices = {} # Reset the model_name index
@ -9798,6 +9799,7 @@ class Router:
- model_id: str - the id of the deployment that was removed
- removal_idx: int - the index where the deployment was removed from model_list
"""
self._discovered_model_info_cache.delete_cache(model_id)
# Update indices for all models after the removed one
for deployment_id, idx in self.model_id_to_deployment_index_map.items():
if idx > removal_idx:
@ -10384,13 +10386,14 @@ class Router:
model_id: Final = deployment.model_info.id
if not limits or model_id is None or self.get_model_info(model_id) is not raw_deployment:
return
self._discovered_model_info_cache.max_size_in_memory = max(len(self.model_list), 1)
self._discovered_model_info_cache.delete_cache(model_id)
self._discovered_model_info_cache.set_cache(
model_id, DiscoveredDeploymentModelInfo(deployment=raw_deployment, limits=limits)
)
self._invalidate_model_group_info_cache()
def _get_discovered_model_info(self, model_id: str | None) -> Mapping[str, int]:
def get_discovered_model_info(self, model_id: str | None) -> Mapping[str, int]:
cached: Final[object] = self._discovered_model_info_cache.get_cache(model_id)
if (
model_id is not None
@ -10428,7 +10431,7 @@ class Router:
model_infos: Final = tuple(
MappingProxyType(
{
**self._get_discovered_model_info((deployment.get("model_info") or MappingProxyType({})).get("id")),
**self.get_discovered_model_info((deployment.get("model_info") or MappingProxyType({})).get("id")),
**MappingProxyType(
{
k: v
@ -10487,7 +10490,7 @@ class Router:
model_info: Final = MappingProxyType(
{
**self._get_discovered_model_info(deployment.model_info.id),
**self.get_discovered_model_info(deployment.model_info.id),
**deployment.model_info.model_dump(exclude_none=True),
}
)
@ -10757,7 +10760,7 @@ class Router:
# values are skipped or Deployment's None pricing defaults would erase the map's
merged_model_info: Final[ModelMapInfo] = {
**copy.deepcopy(model_info),
**self._get_discovered_model_info((deployment.get("model_info") or {}).get("id")),
**self.get_discovered_model_info((deployment.get("model_info") or {}).get("id")),
**MappingProxyType(
{key: value for key, value in (user_model_info or MappingProxyType({})).items() if value is not None}
),
@ -10811,7 +10814,7 @@ class Router:
custom_model_info = (
{ # mutable-ok: the legacy model-info merge updates this private copy
**copy.deepcopy(litellm.model_cost.get(model_id) or MappingProxyType({})),
**self._get_discovered_model_info(model_id),
**self.get_discovered_model_info(model_id),
}
if model_id in litellm.model_cost
else None

View file

@ -28,6 +28,94 @@ from litellm.utils import _invalidate_model_cost_lowercase_map
from .conftest import normalize # type: ignore[import-not-found]
@pytest.mark.parametrize(
("backend_model", "base_model"),
(
("azure/hosted-model", "fallback-model"),
("openai/org/fallback-model", None),
("openai/hosted-model", "fallback-model"),
("openai/fallback-model", "unknown-base-model"),
),
)
@pytest.mark.parametrize("advertised_limit", (None, 2048))
async def test_discovery_preserves_model_info_fallbacks(
backend_model: str, base_model: str | None, advertised_limit: int | None, monkeypatch: pytest.MonkeyPatch
) -> None:
monkeypatch.setattr(litellm, "model_cost", copy.deepcopy(litellm.model_cost))
router: Final = litellm.Router(
model_list=[
{
"model_name": "local",
"litellm_params": {
"model": backend_model,
"api_base": "https://fallback.test/v1",
"api_key": "local-key",
},
"model_info": {"id": "fallback-deployment", "base_model": base_model, "max_output_tokens": 333},
}
]
)
builtin: Final = {
"litellm_provider": "openai",
"mode": "chat",
"max_input_tokens": 7000,
"max_output_tokens": 2000,
"input_cost_per_token": 0.001,
"output_cost_per_token": 0.002,
}
monkeypatch.setattr(
litellm,
"model_cost",
{
"fallback-model": builtin,
"openai/fallback-model": builtin,
"fallback-deployment": {"litellm_provider": "openai", "mode": "chat"},
},
)
_invalidate_model_cost_lowercase_map()
monkeypatch.setattr(proxy_server, "llm_router", router)
handler: Final = AsyncHTTPHandler()
await handler.client.aclose()
async with httpx.AsyncClient(
transport=httpx.MockTransport(
lambda request: httpx.Response(
200,
json={
"data": [
{
"id": backend_model.split("/", 1)[1],
"max_model_len": advertised_limit,
}
]
},
)
)
) as client:
handler.client = client
await router.arefresh_model_info(client=handler)
deployment: Final = {
**router.model_list[0],
"model_info": {**router.model_list[0]["model_info"], "mode": None},
}
enriched_models: Final = (
proxy_server._get_proxy_model_info(copy.deepcopy(deployment)),
proxy_server._enrich_model_info_with_litellm_data(copy.deepcopy(deployment), llm_router=router),
)
expected_input: Final = (
advertised_limit
if advertised_limit is not None and backend_model.startswith("openai/")
else builtin["max_input_tokens"]
)
for enriched in enriched_models:
info: Final = enriched["model_info"]
assert info.get("max_input_tokens") == expected_input
assert info["max_output_tokens"] == 333
assert info["input_cost_per_token"] == builtin["input_cost_per_token"]
assert info["output_cost_per_token"] == builtin["output_cost_per_token"]
assert info["mode"] is None
_invalidate_model_cost_lowercase_map()
async def test_upstream_limits_reach_model_info_routes(
client: TestClient,
auth_as: Callable[[], AbstractContextManager[object]],

View file

@ -21,6 +21,7 @@ import pytest
import litellm
from litellm import Router
from litellm.caching.in_memory_cache import InMemoryCache
from litellm.constants import DEFAULT_MAX_LRU_CACHE_SIZE
from litellm.litellm_core_utils.ptu_pricing import ptu_config_error
from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler
from litellm.llms.openai_like.model_info import MODEL_INFO_REFRESH_SECONDS
@ -65,6 +66,50 @@ def _restore_model_cost_entries(original_entries):
_invalidate_model_cost_lowercase_map()
@pytest.mark.parametrize("initial_count", (1, DEFAULT_MAX_LRU_CACHE_SIZE + 1))
async def test_discovered_limits_survive_deployment_growth_and_removal(
initial_count: int, monkeypatch: pytest.MonkeyPatch
) -> None:
monkeypatch.setattr(litellm, "model_cost", copy.deepcopy(litellm.model_cost))
deployments: Final = tuple(
Deployment(
model_name=f"local-{index}",
litellm_params=LiteLLM_Params(
model="hosted_vllm/local-model", api_base="https://capacity.test/v1", api_key="local-key"
),
model_info=ModelInfo(id=f"capacity-{index}"),
)
for index in range(DEFAULT_MAX_LRU_CACHE_SIZE + 2)
)
router: Final = Router(model_list=[deployment.to_json() for deployment in deployments[:initial_count]])
handler: Final = AsyncHTTPHandler()
await handler.client.aclose()
async with httpx.AsyncClient(
transport=httpx.MockTransport(
lambda request: httpx.Response(200, json={"data": [{"id": "local-model", "max_model_len": 4096}]})
)
) as client:
handler.client = client
await router.arefresh_model_info(client=handler)
assert all(
router.get_configured_token_limits(deployment.model_name) == (4096, 4096)
for deployment in deployments[:initial_count]
)
for deployment in deployments[initial_count:]:
router.add_deployment(deployment)
await router._arefresh_deployment_model_info(router.model_list[-1], client=handler)
assert all(
router.get_configured_token_limits(deployment.model_name) == (4096, 4096) for deployment in deployments
)
for deployment in deployments[-2:]:
router.delete_deployment(deployment.model_info.id or "")
await router._arefresh_deployment_model_info(router.model_list[0], client=handler)
assert all(
router.get_configured_token_limits(deployment.model_name) == (4096, 4096) for deployment in deployments[:-2]
)
_invalidate_model_cost_lowercase_map()
async def test_discovery_discards_metadata_for_a_replaced_deployment(monkeypatch: pytest.MonkeyPatch) -> None:
monkeypatch.setattr(litellm, "model_cost", copy.deepcopy(litellm.model_cost))
router: Final = Router(model_list=[{
@ -131,7 +176,7 @@ async def test_discovery_is_isolated_across_routers_and_reused_ids(monkeypatch:
await first.arefresh_model_info(client=handler)
assert second.get_configured_token_limits("local") == (None, None)
await second.arefresh_model_info(client=handler)
assert first._get_discovered_model_info("shared-discovery-id")["max_input_tokens"] == 8192
assert first.get_discovered_model_info("shared-discovery-id")["max_input_tokens"] == 8192
assert first.get_configured_token_limits("local") == (8192, 8192)
assert second.get_configured_token_limits("local") == (2048, 2048)
assert litellm.model_cost["shared-discovery-id"].get("max_input_tokens") is None