RRDTool: A Round Robin Database for Network Monitoring

Abstract

RRD tool is a circular database that stores time series data. RRD tool assumes time-variable data in intervals of a certain length. An interval is named as a step, and specified upon creation of an RRD file which cannot be changed afterward. Because data may not always come at just the right time, RRD tool will automatically interpolate any submitted data. This is done to fit its internal timestamps. If we compare linear databases with RRD then we can say that RRD is non-linear like a circular queue. Usually, in a Round-Robin Database (RRD), time-series data like network bandwidth, memory usage, and CPU load are stored. The data is stored in a non-linear way so that the system storage footprint remains constant over time. This avoids resource-expensive purge jobs which reduce complexity. MySQL does NOT provide any such kind of storage engine. RRD tool has also the ability to create and feed this database. RRD tool stores data; that makes it a back-end tool. The RRD tool command set allows the creation of graphs which makes it a front-end tool as well. Other databases just store data and cannot create graphs. RRD combined with NET-SNMP can collect data and using scripts we can generate beautiful real-time graphs which can be used for monitoring computer networks.