RRD::Simple provides a simple interface to RRDTool's RRDs module. This module does not currently offer a "fetch" method that is available in the RRDs module.
It does however create RRD files with a sensible set of default RRA (Round Robin Archive) definitions, and can dynamically add new data source names to an existing RRD file.
This module is ideal for quick and simple storage of data within an RRD file if you do not need to, nor want to, bother defining custom RRA definitions.