What are some alternatives?
When comparing eZ Server Monitor and Cacti, you can also consider the following products
PhpSysInfo - phpSysInfo is a customizable PHP script that displays information about your systems.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
netdata - Real-time performance monitoring, done right
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services