persister

A persister is a term used in several domains to describe something or someone that endures or maintains state across changing conditions. The most common uses are in biology, where persister cells are a subpopulation of bacteria that survive antibiotic exposure by entering a dormant state, and in computer science, where a persister is a component responsible for saving and restoring data to durable storage.

In microbiology, persister cells are phenotypic variants that are temporarily tolerant to antibiotics rather than genetically resistant. They survive treatment by reducing metabolic activity and entering a dormant state, allowing them to endure hostile conditions. Once the antibiotic pressure is removed, persisters can reawaken and repopulate, potentially leading to relapse or chronic infections. Persister formation is influenced by stress responses, toxin–antitoxin systems, and nutrient limitation, and it poses challenges for treating infections such as those associated with biofilms and recurrent pneumonia or urinary tract infections.

In software engineering, a persister refers to the persistence layer or component that handles storing and retrieving in-memory objects to durable storage, such as databases or files. A persister typically provides serialization and deserialization, transactional guarantees, and an interface between the domain model and storage systems. It may be implemented as part of a repository, data mapper, or other persistence patterns and can support multiple backends, including relational databases, NoSQL stores, or flat files. The goal is to separate domain logic from storage concerns while ensuring data durability and consistency.

Overall, persisters describe mechanisms or agents that sustain persistence across time, whether in living organisms facing antimicrobial treatment or in software systems ensuring long-term data durability.