RRDtool (round-robin database tool) aims to handle time series data such as network bandwidth, temperatures or CPU load.

The data is stored in a circular buffer based database, thus the system storage footprint remains constant over time.

Bindings exist for several programming languages, e.g. Perl, Python, Ruby, Tcl, PHP and Lua.

A round-robin archive stores a fixed number of CDPs and specifies how many PDPs should be consolidated into one CDP and which CF to use.

The data retrieval function of RRDtool automatically selects the archive with the highest resolution that still covers the requested timespan.