* fix(backend/python): don't await sync servicer behaviors in AsyncModelIdentityInterceptor
The model-identity interceptor (added for #10952) is installed on every Python
backend's gRPC server. Its grpc.aio variant invokes the wrapped servicer
behavior itself and awaits the result unconditionally:
result = await original(request, context) # LoadModel
return await original_unary(request, context) # guarded RPCs
async for response in original_stream(request, context): # streaming
But a backend's servicer methods may be plain sync functions. The transformers
backend, for one, defines `def LoadModel` and `def Embedding` (not `async def`).
grpc.aio's own dispatch adapts both shapes, but this interceptor calls the
behavior directly and bypasses that. For a sync method `original(...)` returns a
message object, not a coroutine, so the `await` raises:
TypeError: object Result can't be used in 'await' expression
The model loads, then the LoadModel RPC dies on return; the guarded sync
Embedding fails the same way. It happens on every platform, not just one backend
build. CI never caught it because AsyncModelIdentityInterceptor had no
behavioral test -- only an "is it installed" assertion.
Fix: await only when the behavior actually returned an awaitable
(inspect.isawaitable), mirroring grpc.aio's own sync/async adaptation. The
streaming guard iterates a sync generator with `for` and an async one with
`async for`.
Adds async-path coverage to model_identity_test.py exercising both sync and
async LoadModel / guarded-unary / streaming behaviors. The sync cases fail on
the current code with the TypeError above and pass with this fix.
Signed-off-by: stefanwalcz <stefan.walcz@walcz.de>
* fix(backend/python): dispatch sync servicer behaviors off the event loop
Addresses review feedback: awaiting only awaitable results removed the
TypeError, but still ran a sync LoadModel/Embedding -- and stepped a sync stream
via next() -- on the asyncio event-loop thread, so a slow load/inference/stream
could freeze all aio RPC handling.
Route sync behavior through run_in_executor (a worker thread) while awaiting
native async behavior directly. A callable wrapper that returns an awaitable is
run in the thread and its awaitable awaited back on the loop. Sync streaming
pulls each item via the executor with a done sentinel, so StopIteration cannot
escape through a Future.
Adds regression tests that record the handler thread id and assert it differs
from the event-loop thread, for LoadModel, a guarded unary RPC and a sync stream.
Signed-off-by: stefanwalcz <stefan.walcz@walcz.de>
---------
Signed-off-by: stefanwalcz <stefan.walcz@walcz.de>
#10970 gave the four PredictOptions RPCs a model-identity check so a
backend reached through a stale distributed route rejects the request
instead of answering from whatever model it holds (#10952). Every other
modality shares that exposure: the route is cached by host:port, a worker
can recycle a stopped backend's port for another model's backend, and a
liveness-only probe cannot tell a stale row from a valid one.
Extends the same mechanism to the 21 remaining request messages that reach
a backend through the router, using the pattern #10970 established rather
than a parallel one:
- proto: ModelIdentity on each modality request message.
- controller: populated from ModelConfig.Model at the call site that also
builds ModelOptions, so load-time and request-time values are equal by
construction.
- backends: one generic guard in pkg/grpc/server.go (27 Go backends), the
method set in backend/python/common (36 Python backends), llama-cpp
(AudioTranscription/Stream, Rerank, Score) and privacy-filter
(TokenClassify).
- reconcile already drops the stale row on IsModelMismatch; no change.
TTSRequest and SoundGenerationRequest get a SEPARATE ModelIdentity field
rather than reusing their existing `model`: FileStagingClient rewrites
`model` to a worker-local path, so comparing it would reject valid
requests in exactly the configuration this guards.
AudioEncode/AudioDecode are deliberately left unguarded: the opus codec
backend is loaded from a literal rather than a ModelConfig, so no value
carries the equality guarantee the comparison depends on. The four
bidirectional stream RPCs are out of scope; they bypass reconcile.
Empty means skip on both sides, so an old controller, an old backend, and
the bare request structs in tests/e2e-backends all keep working.
Assisted-by: Claude Code:claude-opus-4-8 [Read] [Edit] [Bash]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
fix(distributed): reject wrong-model requests at the backend (#10952)
In distributed mode the controller caches a NodeModel row naming a backend's
host:port. A worker can recycle a stopped backend's gRPC port for a different
model's backend, and probeHealth verifies liveness rather than identity, so the
probe succeeds against whatever now occupies the port and the request is
dispatched to the wrong backend. The caller gets a silent wrong-model answer.
Nothing in the request could catch this: PredictOptions had no model field, so
model identity crossed the wire only in ModelOptions.Model at LoadModel time,
and the cached-hit path issues no LoadModel. Every backend's "model not loaded"
guard checks a nil handle, which a process holding a different model passes, so
the stale row was never dropped either.
Add PredictOptions.ModelIdentity and enforce it at the point of use:
- The controller populates it in gRPCPredictOpts from ModelConfig.Model, the
same expression ModelOptions feeds to model.WithModel and therefore the
same value the backend received as ModelOptions.Model. Both are read from
one config value in one function, so they are equal by construction and the
comparison cannot false-reject.
- Backends compare it against what they loaded and return NOT_FOUND with a
fixed sentinel. Enforced in pkg/grpc/server.go (27 Go backends), an
interceptor in backend/python/common (all 36 Python backends, no
per-backend change), and the llama-cpp / ik-llama-cpp / ds4 C++ servers.
That is every backend with real exposure: kokoros answers all four RPCs
with unimplemented and privacy-filter implements none of them.
- The router's reconcile drops the stale replica row on a mismatch, so the
next request reloads somewhere correct.
Empty means "skip the check" on both sides: a controller that predates the
field sends nothing, a backend loaded by such a controller has nothing to
compare, and the C++ server synthesizes PredictOptions internally for ASR. That
keeps upgrades working in both directions.
Scoped to the four PredictOptions RPCs. TTSRequest.model and
SoundGenerationRequest.model are deliberately NOT validated: FileStagingClient
already rewrites them to worker-local absolute paths, so in distributed mode
they already differ from the load-time value and comparing them would reject
valid requests.
IsModelMismatch requires both the NOT_FOUND code and the sentinel, unlike the
neighbouring helpers which accept either. insightface's Embedding returns
NOT_FOUND "no face detected" on a PredictOptions RPC, and a code-only check
would drop a healthy replica row on every faceless image.
Assisted-by: Claude Code:claude-opus-4-8[1m] [Read] [Edit] [Bash]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
