AML: An accuracy metric model for effective evaluation of log parsing techniques

Logs are essential for the maintenance of large software systems. Software engineers often analyze logs for debugging, root cause analysis, and anomaly detection tasks. Logs, however, are partly structured, making the extraction of useful information from massive log files a challenging task. Recently, many log parsing techniques have been proposed to automatically extract log templates from unstructured log files. These parsers, however, are evaluated using different accuracy metrics. In this paper, we show that these metrics have several drawbacks, making it challenging to understand the strengths and limitations of existing parsers. To address this, we propose a novel accuracy metric, called AML (Accuracy Metric for Log Parsing). AML is a robust accuracy metric that is inspired by research in the field of remote sensing. It is based on measuring omission and commission errors. We use AML to assess the accuracy of 14 log parsing tools applied to the parsing of 16 log datasets. We also show how AML compares to existing accuracy metrics. Our findings demonstrate that AML is a promising accuracy metric for log parsing compared to alternative solutions, which enables a comprehensive evaluation of log parsing tools to help better decision-making in selecting and improving log parsing techniques.