ERROR:tf2onnx.tfonnx:Tensorflow op [sequential_1/bidirectional_1/forward_lstm_1/CudnnRNNV3: CudnnRNNV3] is not supported

[josephgiting]

Open this issue following the discussion from #21533 (comment)

Export the following model using:

keras==3.12.0
tf2onnx-1.16.1
onnx-1.19.1
protobuf-3.20.3
tensorflow==2.19.0

  model = Sequential()
  model.add(Input(shape=(sam_sz, num_features_in))) # Use calculated input shape
  for _ in range(conv_lay):
    model.add(Conv1D(filters=filter, kernel_size=ker_size, activation=act, padding='same', data_format='channels_last'))
    model.add(MaxPooling1D(pool_size=pool_size, data_format='channels_last'))
  for _ in range(lstm_lay):
    # For intermediate LSTM layers, return sequences
    model.add(Bidirectional(LSTM(100, return_sequences = True, kernel_regularizer=l2(0.0001)))) # Use Bidirectional LSTM
    model.add(Dropout(0.3))
  model.add(Bidirectional(LSTM(100, return_sequences = False, kernel_regularizer=l2(0.0001)))) # Use Bidirectional LSTM
  model.add(Dropout(0.3))
  model.add(Dense(units=3, activation = act2, kernel_regularizer=l2(0.0001)))

with:
model.export(output_path, format="onnx")

observed the following issues:

WARNING:tf2onnx.shape_inference:Cannot infer shape for sequential_1/bidirectional_1/forward_lstm_1/CudnnRNNV3: sequential_1/bidirectional_1/forward_lstm_1/CudnnRNNV3:3,sequential_1/bidirectional_1/forward_lstm_1/CudnnRNNV3:4
WARNING:tf2onnx.shape_inference:Cannot infer shape for sequential_1/bidirectional_1/backward_lstm_1/CudnnRNNV3: sequential_1/bidirectional_1/backward_lstm_1/CudnnRNNV3:3,sequential_1/bidirectional_1/backward_lstm_1/CudnnRNNV3:4
ERROR:tf2onnx.tfonnx:Tensorflow op [sequential_1/bidirectional_1/forward_lstm_1/CudnnRNNV3: CudnnRNNV3] is not supported
ERROR:tf2onnx.tfonnx:Tensorflow op [sequential_1/bidirectional_1/backward_lstm_1/CudnnRNNV3: CudnnRNNV3] is not supported
ERROR:tf2onnx.tfonnx:Unsupported ops: Counter({'CudnnRNNV3': 2})

Would appreciate your attention.

[dhantule]

Hi @josephgiting, thanks for reporting this.
I've tested your code with Keras 3.12.0 and I'm not able to reproduce the error you've mentioned, please refer this gist, let me know if I missed anything.

[josephgiting]

@dhantule
Many thanks for looking into this issue so quickly.
Using your link, I rerun it on Google Colab with T4 GPU runtime type, and you can observe the issue there (and with pip freeze info.):
https://colab.research.google.com/gist/josephgiting/bde42a3999e9cd764984b5aec156a41e/-21799.ipynb

NOTE: This issue is not reproducible with CPU runtime type.

Please let me know if I can assist further.
Kind Regards,

[dhantule]

Hi @josephgiting, thanks for letting me know, we'll look into this.

[mattdangerw]

To me this looks like a spot where tf2onnx does not support the required ops we'd need for rnn model export. I am not sure if that is something we could fix on the Keras side, but it would be great to add support for in tf2onnx.

Here's a relevant issues -> onnx/tensorflow-onnx#2359

You might be able to skirt around the issue by passing use_cudnn=False to your RNN layers for now. Long term we'd probably want to add support in tf2onnx unless there's a particular reason not too.

Also tagging @james77777778 who added onnx support, in case he has any ideas how we could work around this during export so things work while we are missing coverage for these ops.

[josephgiting]

Thanks @mattdangerw

I have updated my gist with use_cudnn=False and it works.

Loading the the ONNX model with onnxruntime is good too.

[mattdangerw]

Thanks! I think we can leave this open as the bug is still valid. But just to track while we wait for support from tfonnx.

[josephgiting]

Experiments show that setting use_cudnn=False significantly increases training time, which likely indicates that CUDA (GPU acceleration) is not being utilized — effectively the same as running on CPU. Hence not seeing this issue.

If that’s the case, the relevant team may need to investigate and fix this issue.