  A hot fix is an unplanned improvement to a specific time-critical issue
deployed to a software system in production. While hot fixing is an essential
and common activity in software maintenance, it has never been surveyed as a
research activity. Thus, such a review is long overdue. In this paper, we
conduct a comprehensive literature review of work on hot fixing. We highlight
the fields where this topic has been addressed, inconsistencies we identified
in the terminology, gaps in the literature, and directions for future work. Our
search concluded with 91 articles on the topic between the years 2000 and 2022.
The articles found encompass many different research areas such as log
analysis, runtime patching (also known as hot patching), and automated repair,
as well as various application domains such as security, mobile, and video
games. We find that many directions can take hot fix research forward such as
unifying existing terminology, establishing a benchmark set of hot fixes,
researching costs and frequency of hot fixes, and researching the possibility
of end-to-end automation of detection, mitigation, and deployment. We discuss
these avenues in detail to inspire the community to systematize hot fixing as a
software engineering activity.
