Paddy: An Event Log Parsing Approach using Dynamic Dictionary

Large enterprise systems often produce a large volume of event logs, and event log parsing is an important log management task. The goal of log parsing is to construct log templates from log messages and convert raw log messages into structured log messages. A log parser can help engineers monitor their systems and detect anomalous behaviors and errors. Most existing log parsing methods focus on offline methods, which require all log data to be available before parsing. In addition, the massive volume of log messages makes the process complex and time-consuming. In this paper, we propose Paddy, an online event log parsing method. Paddy uses a dynamic dictionary structure to build an inverted index, which can search the template candidates efficiently with a high rate of recall. The use of Jaccard similarity and length feature to rank candidates can improve parsing precision. We evaluated our proposed method on 16 real log datasets from various sources including distributed systems, supercomputers, operating systems, mobile systems, and standalone software. Our experimental results demonstrate that Paddy achieves the highest accuracy on eight data sets out of sixteen datasets compared to other baseline methods. We also evaluated the robustness and runtime efficiency of the methods and the experimental results show that our method Paddy achieves superior stableness and is scalable with a large volume of log messages.