Log severity levels matter: A multivocal mapping

TL;DR

This study systematically maps log severity levels across literature, libraries, and practitioners, revealing redundancies and proposing a standardized set of six levels to improve log reliability.

Contribution

It provides a comprehensive mapping of severity levels, synthesizes six standardized definitions, and offers practical guidelines for developers and library creators.

Findings

Redundancy and semantic similarity among severity levels

Convergence towards six standardized severity levels

Recommendations for standard nomenclature and clear definitions

Abstract

The choice of log severity level can be challenging and cause problems in producing reliable logging data. However, there is a lack of specifications and practical guidelines to support this challenge. In this study, we present a multivocal systematic mapping of log severity levels from peer-reviewed literature, logging libraries, and practitioners' views. We analyzed 19 severity levels, 27 studies, and 40 logging libraries. Our results show redundancy and semantic similarity between the levels and a tendency to converge the levels for a total of six levels. Our contributions help leverage the reliability of log entries: (i) mapping the literature about log severity levels, (ii) mapping the severity levels in logging libraries, (iii) a set of synthesized six definitions and four general purposes for severity levels. We recommend that developers use a standard nomenclature, and for logging library creators, we suggest providing accurate and unambiguous definitions of log severity levels.