RRDtool 1.x master build status: 
test coverage
RRDtool is a little program for easily maintaining a database of time-series data. It comes with a charting program for drawing pretty graphs based on the data stored.
It is pretty easy to gather status information from all sorts of things, ranging from the temperature in your office to the number of octets which have passed through the FDDI interface of your router. But it is not so trivial to store this data in a efficient and systematic manner. This is where RRDtool kicks in. It lets you log and analyze the data you gather from all kinds of data-sources (DS). The data analysis part of RRDtool is based on the ability to quickly generate graphical representations of the data values collected over a definable time period.
check out the instructions in doc/rrdbuild.pod
Either after compiling or after installing you can try the example RRDtool applications in the examples directory.
Read the documentation in the doc directory.
If you are looking for a more slow paced introduction, make sure to read Alex van den Bogaerdt's rrdtutorial which is also available from the doc directory. Also read his cdeftutorial and Steve Rader's rpntutorial.
If you want to know about the format of the log files check src/rrd_format.h there are a lot of comments in there ...
If you want to show your appreciation for RRDtool you could make me happy by going to https://tobi.oetiker.ch/wish and ordering a CD from my CD wish list ...
There are 3 Mailing lists for RRDtool:
rrd-announce LOW volume RRDtool Announcements List (Only Stable Releases) rrd-users For discussion amongst people who use RRDtool in their applications rrd-developers For people who actually HACK RRDtool code
To subscribe to send a message with the subject 'subscribe' to -request@lists.oetiker.ch
Note, that postings to rrd-announce will always be cross-posted to rrd-users and rrd-developers as well.
Contributed feature and bug patches are most welcome. Since rrdtool lives on github, it is now very easy to create pull requests. Work from the master branch unless you are creating bugfixes. No new features should go into the 1.2, 1.3 and 1.4 branches.
If you contribute new features, make sure to also update the documentation pod files.
Is always available from https://oss.oetiker.ch/rrdtool/
Tobias Oetiker tobi@oetiker.ch