<i>"OpenTSDB is a distributed, scalable Time Series Database (TSDB) written on top of HBase. OpenTSDB was written to address a common need: store, index and serve metrics collected from computer systems (network gear, operating systems, applications) at a large scale, and make this data easily accessible and graphable."</i><p><a href="http://opentsdb.net/" rel="nofollow">http://opentsdb.net/</a>