When creating an RRD database we'll need to specify a couple things, namely one or more Data Sources and one or more Round Robin Archives. The data source (DS) defines what type of data is accepted and some boundaries on what constitutes good data. The round robin archives (RRA) can almost be thought of as views, it defines the different ways we can store and retrieve data.
tutorial programming rrdtoolRRDtool refers to Round Robin Database tool. Round robin is a technique that works with a fixed amount of data, and a pointer to the current element. Think of a circle with some dots plotted on the edge. These dots are the places where data can be stored. Draw an arrow from the center of the circle to one of the dots; this is the pointer. When the current data is read or written, the pointer moves to the next element. As we are on a circle there is neither a beginning nor an end, you can go on and on and on. After a while, all the available places will be used and the process automatically reuses old locations.
tutorial sysadmin networking rrdtoolRRDtool is a graphing utility made by Tobi Oetiker that takes data sets you collect and graphs them. RRDtool (acronym for round-robin database tool) correlates time-series data like network bandwidth, temperatures, CPU load or any other data type. Data is stored in a round-robin database (circular buffer) which allows the system storage footprint to remain constant over time. The database will always have the same amount of data points throughout its lifetime. When new data comes in the oldest data set is removed.
tutorial sysadmin rrdtool