InfluxData - Scalable datastore for metrics, events, and real-time analytics.
Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
TimescaleDB - TimescaleDB is a time-series SQL database providing fast analytics, scalability, with automated data management on a proven storage engine.
SQLite - SQLite Home Page
Prometheus - An open-source systems monitoring and alerting toolkit.
PouchDB - Open-source JavaScript database inspired by Apache CouchDB that's designed to run well within the browser