Open-source OLAP database designed for real-time analytics at scale.

49.5k stars8.9k forksApache-2.0last commit Actively maintained
Managed cloud offering of QuestDB providing a hosted time-series database optimized for real-time ingestion and SQL analytics of machine data (metrics, IoT, financial ticks). Includes hosted clusters, ingestion APIs, SQL query interface, retention and scaling features.
Open-source OLAP database designed for real-time analytics at scale.

49.5k stars8.9k forksApache-2.0last commit Actively maintained
InfluxDB is an open source time-series database for high-ingest metrics and event data, enabling fast queries for monitoring, dashboards, and real-time analytics.

31.7k stars3.7k forksApache-2.0last commit Actively maintained
Apache Druid is a real-time analytics (OLAP) database delivering sub-second queries on streaming and batch data with high concurrency at scale.

14k stars3.8k forksApache-2.0last commit Actively maintained
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 3 of 3 shipped a commit in the last six months. Licences in this list: Apache-2.0. In exchange you take on hosting, backups and updates yourself.
Browse everything in Time-Series Databases.