Hue: A User-Adaptive Parser for Hybrid Logs

TL;DR

Hue introduces a user-adaptive hybrid log parser that effectively handles both single-line and multi-line logs, outperforming existing methods and demonstrating practical deployment in real-world environments.

Contribution

Hue is the first hybrid log parser that supports both log types and incorporates user feedback for adaptive, accurate log template extraction.

Findings

Achieves 0.845 accuracy on hybrid logs, surpassing existing parsers' 0.563

Outperforms state-of-the-art on single-line log datasets

Successfully deployed in a real production environment

Abstract

Log parsing, which extracts log templates from semi-structured logs and produces structured logs, is the first and the most critical step in automated log analysis. While existing log parsers have achieved decent results, they suffer from two major limitations by design. First, they do not natively support hybrid logs that consist of both single-line logs and multi-line logs (\eg Java Exception and Hadoop Counters). Second, they fall short in integrating domain knowledge in parsing, making it hard to identify ambiguous tokens in logs. This paper defines a new research problem, \textit{hybrid log parsing}, as a superset of traditional log parsing tasks, and proposes \textit{Hue}, the first attempt for hybrid log parsing via a user-adaptive manner. Specifically, Hue converts each log message to a sequence of special wildcards using a key casting table and determines the log types via line aggregating and pattern extracting. In addition, Hue can effectively utilize user feedback via a novel merge-reject strategy, making it possible to quickly adapt to complex and changing log templates. We evaluated Hue on three hybrid log datasets and sixteen widely-used single-line log datasets (\ie Loghub). The results show that Hue achieves an average grouping accuracy of 0.845 on hybrid logs, which largely outperforms the best results (0.563 on average) obtained by existing parsers. Hue also exhibits SOTA performance on single-line log datasets. Furthermore, Hue has been successfully deployed in a real production environment for daily hybrid log parsing.