Add Prometheus

An open-source service monitoring system and time series database

README.md

@@ -284,6 +284,7 @@ A curated list of amazingly awesome open source sysadmin resources inspired by [
 * [InfluxDB](http://influxdb.com/) - Open source distributed time series database with no external dependencies.
 * [KairosDB](https://code.google.com/p/kairosdb/) - Fast distributed scalable time series database, fork of OpenTSDB 1.x.
 * [OpenTSDB](http://opentsdb.net/) - Store and server massive amounts of time series data without losing granularity.
+* [Prometheus](http://prometheus.io/) - An open-source service monitoring system and time series database.
 * [RRDtool](http://oss.oetiker.ch/rrdtool/) - Open source industry standard, high performance data logging and graphing system for time series data.
 * [Statsd](https://github.com/etsy/statsd/) - Application statistic listener.