In my early days, when I was working as a network engineer, we used the open source cross-platform Multi Router Traffic Grapher (MRTG, https://en.wikipedia.org/wiki/Multi_Router_Traffic_Grapher) tool to check the traffic load on network links. It was one of the first open source high-level network monitoring system that abstracted the details of SNMP, database, and HTML for network engineers. Then came Round-Robin Database Tool (RRDtool, https://en.wikipedia.org/wiki/RRDtool). In its first release in 1999, it was referred to as "MRTG done right". It had greatly improved the database and poller performance in the backend.

Released in 2001, Cacti (https://en.wikipedia.org/wiki/Cacti_(software)) is an open source web-based network monitoring and graphing tool designed as an improved frontend for RRDtool. Because of the heritage of MRTG and RRDtool, you will notice a familiar graph layout, templates, and SNMP poller. As a packaged tool, the installation and usage will need to stay within the boundary of the tool itself. However, Cacti offers the custom data query feature that we can use Python for. In this section, we will see how we can use Python as an input method for Cacti.