Classifying and Comparing Latent Space Representation of Unstructured Log Data.

Abstract: This thesis explores and compares various methods for producing vector representation of unstructured log data. Ericsson wanted to investigate machine learning methods to analyze logs produced by their systems to reduce the cost and effort required for manual log analysis. Four NLP methods were used to produce vector embeddings for logs: Doc2Vec, DAN, XLNet, and RoBERTa. Also, a Random forest classifier was used to classify those embeddings. The experiments were performed on three different datasets and the results showed that the performance of the models varied based on the dataset being used. The results also show that in the case of log data, fine-tuning makes the transformer models computationally heavy and the performance gain is very low. RoBERTa without fine-tuning produced optimal vector representations for the first and third datasets used whereas DAN had better performance for the second dataset. The study also concluded that the NLP models were able to better understand and classify the third dataset as it contained more plain text information as contrasted against more technical and less human readable datasets.