Essential SNMP, 2nd Edition

Chapter 13. RRDtool and Cricket

This chapter discusses RRDtool and Cricket. RRDtool, written by the author of MRTG, was meant to be a replacement for MRTG. Instead, MRTG lived on and RRDtool found a place all its own in the world of network performance management. Unlike MRTG, RRDtool has a plethora of frontends written by people all over the world. One of the first and most widely known is Cricket. This chapter shows how to install RRDtool and Cricket on Unix. RRDtool can certainly be used alone, but the goal of this chapter is to demonstrate the easiest and quickest way to get up and running with both tools.

RRDtool

RRDtool is the 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. After a while, all the available places are used and the process automatically reuses old locations. This way, the dataset does not grow in size and therefore requires no maintenance. RRDtool works with Round Robin Databases (RRDs). It stores and retrieves data from them.

RRDtool originated from MRTG, which we cover in Chapter 12. MRTG started as a tiny little script for graphing the use of a university's connection to the Internet. MRTG was later used (some might ...