InfluxData - Scalable datastore for metrics, events, and real-time analytics.
OpenTSDB - OpenTSDB is a distributed, scalable Time Series Database (TSDB) written on top of HBase.
Cortex Project - Horizontally scalable, highly available, multi-tenant, long term Prometheus.
Axibase Time Series Database - ATSD is purpose-built for analyzing and reporting on massive volumes of time-series data collected...
TimescaleDB - TimescaleDB is a time-series SQL database providing fast analytics, scalability, with automated data management on a proven storage engine.
RRDTool - High performance data logging and graphing system for time series data