GraphComponentException if `hidden_layers_size` used with only one (text) overwritten key

Rasa Open Source version

3.0.0

Rasa SDK version

3.0.0

Rasa X version

No response

Python version

3.8

What operating system are you using?

Windows

What happened?

I wanted to train a migrated AI with the following config for DIETClassifier:

- name: DIETClassifier
  random_seed: 42
  loss_type: cross_entropy
  model_confidence: softmax
  constrain_similarities: True
  intent_classification: True
  entity_recognition: False
  use_masked_language_model: True
  epochs: 80
  number_of_transformer_layers: 4
  transformer_size: 256
  drop_rate: 0.2
  batch_size: [64, 256]
  embedding_dimension: 50
  hidden_layers_sizes:
    text: [512, 128]

The result was the following error:

  File "...rasa\nlu\classifiers\diet_classifier.py", line 1277, in __init__
    self._prepare_layers()
  File "...rasa\nlu\classifiers\diet_classifier.py", line 1437, in _prepare_layers
    self.config[HIDDEN_LAYERS_SIZES][self.label_name],
  File "...wrapt\wrappers.py", line 394, in __getitem__
    return self.__wrapped__[key]
KeyError: 'label'

followed by

rasa.engine.exceptions.GraphComponentException: Error running graph component for node train_DIETClassifier5.

After digging into it, it seems to me, that even if the documentation sais:

hidden_layers_sizes: This parameter allows you to define the number of feed forward layers and their output dimensions for user messages and intents (default: text: [], label: []). 

it is not enough to specify only one of the keys. After changing the config to:

  hidden_layers_sizes:
    text: [512, 128]
    label: []

everything worked fine. I am not absolutely sure but this worked in Rasa 2.8.x.

Command / Request

No response

Relevant log output

2021-11-25 14:36:48 INFO     rasa.engine.training.hooks  - Restored component 'LexicalSyntacticFeaturizer' from cache.
2021-11-25 14:36:48 INFO     rasa.engine.training.hooks  - Restored component 'CountVectorsFeaturizer' from cache.
2021-11-25 14:36:48 INFO     rasa.engine.training.hooks  - Restored component 'CountVectorsFeaturizer' from cache.
2021-11-25 14:36:48 INFO     rasa.engine.training.hooks  - Restored component 'MemoizationPolicy' from cache.
2021-11-25 14:36:48 INFO     rasa.engine.training.hooks  - Restored component 'RulePolicy' from cache.
2021-11-25 14:36:49 INFO     rasa.engine.training.hooks  - Starting to train component 'DIETClassifier'.
...
  File "...rasa\nlu\classifiers\diet_classifier.py", line 1277, in __init__
    self._prepare_layers()
  File "...rasa\nlu\classifiers\diet_classifier.py", line 1437, in _prepare_layers
    self.config[HIDDEN_LAYERS_SIZES][self.label_name],
  File "...wrapt\wrappers.py", line 394, in __getitem__
    return self.__wrapped__[key]
KeyError: 'label'

Definition of Done:

• Discovered the problem
• Fixed the problem
• Made sure the same problem does not exist for other parameters of the component and also other ML components like TEDPolicy, ResponseSelector and UnexpecTEDIntentPolicy
• Model regression tests run on the PR
• PR is merged to 3.0.x
• New micro version released after the bugfix is merged.

[mleimeister]

Scheduled for next upcoming micro release with Enable squat.

[mleimeister]

Hi, thanks for the feedback! In that case I’ll also check the CountVectorsFeaturizer config. I added some documentation on the potential cause I think I found and steps I implemented for a possible fix in the second PR’s comment. Since it would touch a core part of the components, it would be great though to discuss if this is actually the correct root cause, and if so a viable fix.