InfluxDB - DB for metrics and analytics

http://influxdb.com

An open-source, distributed, time series database*
with no external dependencies.
InfluxDB is the new home for all of your metrics, events, and analytics.

Time series database - https://en.wikipedia.org/wiki/Time_series_database

A time series database (TSDB) is a software system that is optimized for handling time series data, arrays of numbers indexed by time (a datetime or a datetime range). In some fields these time series are called profiles, curves, or traces. A time series of stock prices might be called a price curve. A time series of energy consumption might be called a load profile. A log of temperature values over time might be called a temperature trace.