Cube!

RRDtool (acronym for round-robin database tool) aims to handle time-series data like network bandwidth, temperatures, CPU load, etc. The data are stored in a round-robin database (circular buffer), thus the system storage footprint remains constant over time.It also includes tools to extract RRD data in a graphical format, for which it was originally intended.Bindings exist for Perl, Python, Ruby, Tcl, PHP and Lua. One independent full Java implementation exists: rrd4j.General data storageRRDtool assumes time-variable data in intervals of a certain length. This interval, usually named step, is specified upon creation of an RRD file and cannot be changed afterwards. Because data may not always be available at just the right time, RRDtool will automatically interpolate any submitted data to fit its internal time-steps.The value for a specific step, that has been interpolated, is named a primary data point (PDP). Multiple PDPs may be consolidated according to a consolidation function (CF) to form a consolidated data point (CDP). Typical consolidation functions are average, minimum, maximum. »

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.

Axibase Time-Series Database (ATSD) is a next-generation statistics database. ATSD is for companies that need to extract value from large amounts of time-series data which exists in their IT and operational infrastructure. Built on top of Hadoop Distributed File System (HDFS), ATSD delivers scalability and performance beyond relational database limitations.

Beringei is a high performance, in-memory storage engine for time series data.

Reconnoiter is a monitoring and trend analysis system designed to cope with large architectures (thousands of machines and hundreds of thousands of metrics).

A relaxing hosted time series database. TSDB with sophisticated querying, joining and aggregation via HTTP REST API. Storage from 1 GB to Terabytes. On-Demand and Pay-Per-Use. Cloud ready.