Cacti 0.8 Network Monitoring: Monitor your network with ease!

Cacti is an open source, network monitoring and graphing tool written in PHP/MySQL. It uses the RRDTool (Round-robin database tool) engine to store data and generate graphics, and collects periodical data through Net-SNMP (an application suite to implement SNMP—Simple Network Management Protocol).

Ian Berry had started developing Cacti back in June 2001, while he was working with a local Internet service provider in the U.S. He found that RRDTool is flexible enough to generate complex graphing and reports about network infrastructures, but it was lacking a friendly interface. So, he started developing the interface with PHP/MySQL and had the first public release (version 0.6) on November 21, 2001. Soon, the application gained its popularity in the open source community.

In 2004, Ian brought a second developer into the team, which has expanded to six developers today. Here they are (in the order of joining the project):

First of all, Cacti is an open source tool. Classically, it can graph network bandwidth with SNMP; but a lot of different graphing can be done with SNMP, Perl, or Shell scripts. There are several important reasons why a system administrator should choose Cacti as a network monitoring tool—it is by far the best RRDTool front-end:

Cacti operation is divided into three different tasks:

In today's complex network of routers, switches, servers, and UPS, it can be a daunting task to manage all the devices on a network and make sure they're not only up and running but also performing optimally. This is where Simple Network Management Protocol (SNMP) can help. SNMP was introduced in 1988 to meet the growing need for a standard for managing Internet Protocol (IP) devices.

Net-SNMP is a suite of software for using and deploying SNMP protocol (version v1, v2c, and v3) and AgentX subagent protocol. It supports IPv4, Ipv6, IPX, AAL5, UNIX domain sockets and others. The suite includes:

The root of the Net-SNMP goes all the way back to 1992; Steve Waldbusser of Carnegie-Mellon University started a freely available SNMP tool kit. Later, Wes Hardaker at University of California Davis took over the project. He extended the agent to provide more information about his local systems (a private precursor to the Host Resources MIB) and to flag certain error situations. He also added a simple way for the agent to run additional scripts and report the results, turning it into an extensible agent. In 1995, this code was made publicly available.

RRDTool is a high performance data logging and graphing system, designed to handle time series data like network bandwidth, room temperature, CPU load, server load, and to monitor devices such as routers, UPS, etc. It is also known as the round-robin database tool, an industry standard, open source solution. It lets the administrator log and analyze data collected from all kinds of data sources (DS), which are capable of answering SNMP queries. The data analysis part of the RRDTool is based on the ability to generate graphical representations of the data values collected over a definable time period.

RRDTool is developed by Tobi Oeticker, also known for his famous creation MRTG. RRDTool is written in C language and stores its data in .rdd files. The number of records in a single .rrd file never increases, meaning that old records are frequently removed, and it presents useful graphs by processing the data to enforce a certain data density. RRDTool offers several command line switches to access and manipulate .rdd files:

There are also a number of language bindings for RRDTool, which allow administrators or programmers to use it directly from Perl, Python, tcl, PHP, and Ruby. So, it can be used to write custom monitoring shell scripts or create whole applications using its language bindings. Cacti is an application written in PHP, using its PHP language binding.

Now, we have a basic knowledge about the Cacti application and its operation by using Net-SNMP and the RRDTool. Cacti is a one-stop, web-based solution to monitor network infrastructure and resources. It's easy to use and configure. The most amazing thing about it—you don't need to be an expert Linux administrator to use it. So, let's see how to install Cacti.