# Incremental training and Auto Machine Learning for big datasets

I built a NLP sentence classifier, which uses vectors from word embedding as features.

Training dataset is big (100k sentences). Every sentence has 930 features.

I found the best model using an auto machine learning library (auto-sklearn); the training required 40 GB of RAM and 60 hours. The best model is an ensemble of the top N models found by this library.

Occasionally, I need to add some data to the training set and update the training. Since this autoML library isn't suitable for incremental training, every time I need to do complete retraining, using more and more memory and time.

How to address this issue? How to do incremental training? Should I quit the usage of this library? For memory and time usage, would it be better to parallelize the training?

First of all using auto-sklearn, you can use

automl.fit(X_train, y_train, dataset_name='X_train',
feat_type=feature_types)

print(automl.show_models())


so you can extract the instance of the best model from the first fitting. However in order to learn incrementally you have to (in case of sklearn models) have fit_partially method. Naive Bayes varaints and other algorithms here have this functionality. So you are out of luck if these are not in the output of show_models: In this case you ought to do your own automated ml targeted on fit_partial models.

Alternative is using spark it has some cool streaming (incremental learning algos) StreamingKMeans, StreamingLinearRegressionWithSGD, StreamingLogisticRegressionWithSGD and generally StreamingLinearAlgorithm.

To conclude, I would not use auto-sklearn if these are your problems and choose some alternatives that do work parallel.

• Do you know if exists an autoML library which supports incremental training out of the box? Jan 13 '20 at 13:23
• Not that I have heard of, but its easy to implement something like that. In any case I would advise against it. there is no magical button that solves your problem optimally (or even close to optimum) AutoML are approaximations at best (there are excepections where they work well) I am speaking in general Jan 13 '20 at 14:22