A collection of modules providing apis for integrating drupal with RRDtool, the round-robin
database tool, used for tracking time-series data. The rrdtool module provides apis for writing data to and generating graphs from round-robin databases. The rrdtool_monitors module provides apis for incrementing counters in a persistent, distributed data store (currently only memcache is supported). And the rrdtool_drupal module tracks statistics from Drupal's core apis.
All three modules can run on the same web server, or the rrdtool_monitors and rrdtool_drupal modules can be enabled on multiple production webservers with the rrdtool module enabled only on one or more private monitoring servers.
For this module to work, you will need to install the rrdtool php extension on the server that does the actual logging. Please refer to the included README to learn how to install it.