oftenused

Oftenused is an open-source library and API designed to identify and expose items that are accessed frequently by an application. The central idea is to rank resources—such as files, API endpoints, or in-memory objects—according to observed access frequency to inform optimization decisions.

Originating in the software performance community, oftenused provides language-agnostic patterns that can be implemented across languages. It has seen integrations in web servers, data processing pipelines, and client applications, with adapters for JavaScript, Python, and Go in common deployments.

Key features include frequency tracking with configurable decay, top-n queries to retrieve the most-used items, and pluggable backends for in-memory, Redis, or SQL storage. It supports lightweight counters, sampling to reduce overhead, and optional privacy-preserving modes for sensitive environments.

Architecture typically comprises event collectors that emit access events, a counter layer that updates usage statistics, and a query layer that serves top items to caches or dashboards. Counters may employ time-based windows or exponential decay to reflect recent usage more accurately.

Usage involves instrumenting access points, selecting an appropriate decay and storage backend, and querying for top items to drive caching, prefetching, or resource allocation. Operators should balance accuracy, latency, and memory usage, and consider data retention policies.

See also: caching strategies, prefetching, frequency analysis.