Feast Serving should notify users of invalid feature names #454

online_features = client.get_online_features(
    feature_refs=[
        f"daily_transactions:3",
        f"total_transactions:3",
    ],
    entity_rows=[
        GetOnlineFeaturesRequest.EntityRow(
            fields={
                "customer_id": Value(
                    int64_val=1001)
            }
        )
    ],
)
print(online_features)

InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
	status = StatusCode.UNKNOWN
	details = ""
	debug_error_string = "{"created":"@1580607090.708289999","description":"Error received from peer ipv4:172.28.0.8:6566","file":"src/core/lib/surface/call.cc","file_line":1056,"grpc_message":"","grpc_status":2}"
>

2020-02-02 01:31:30.703  WARN 690ef6bd9e82 --- [ault-executor-1] f.s.c.ServingServiceGRpcController       : Failed to get Online Features
feast.serving.exception.SpecRetrievalException: Unable to retrieve feature project: "customer_project"
name: "daily_transactions"
version: 3

        at feast.serving.specs.CachedSpecService.lambda$getFeatureSets$0(CachedSpecService.java:120)
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
        at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472)
        at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
        at feast.serving.specs.CachedSpecService.getFeatureSets(CachedSpecService.java:124)
        at feast.serving.service.RedisServingService.getOnlineFeatures(RedisServingService.java:96)
        at feast.serving.controller.ServingServiceGRpcController.getOnlineFeatures(ServingServiceGRpcController.java:73)
        at feast.serving.ServingServiceGrpc$MethodHandlers.invoke(ServingServiceGrpc.java:495)
        at io.grpc.stub.ServerCalls$UnaryServerCallHandler$UnaryServerCallListener.onHalfClose(ServerCalls.java:171)
        at io.grpc.internal.ServerCallImpl$ServerStreamListenerImpl.halfClosed(ServerCallImpl.java:283)
        at io.grpc.internal.ServerImpl$JumpToApplicationThreadServerStreamListener$1HalfClosed.runInContext(ServerImpl.java:710)
        at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
        at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)