Munin

Munin is an open-source network and system monitoring tool used for collecting, analyzing, and visualizing server and infrastructure performance metrics. It gathers data such as CPU usage, memory consumption, disk activity, network traffic, and system processes, then generates historical graphs and reports that help administrators monitor system health and identify performance trends.

• Provides automated monitoring of servers, systems, and network resources.
• Collects metrics including CPU, memory, disk usage, network activity, and processes.
• Generates historical graphs for performance analysis and trend tracking.
• Uses a plugin-based architecture for extending monitoring capabilities.
• Supports monitoring multiple hosts from a centralized server.
• Offers automatic plugin detection and configuration.
• Provides web-based visualization through generated HTML pages and charts.
• Supports alerts and threshold-based notifications.

Run following commands to check status:
$sudo su
$systemctl status munin-node
$sudo -u munin munin-cron

Start Munin and Apache 
$sudo systemctl restart munin-node
$sudo systemctl restart apache2

Disclaimer: Munin is an open-source monitoring solution intended for tracking system and network performance metrics. Monitoring accuracy and performance may vary depending on enabled plugins, system resources, operating system configuration, and server environment. Proper plugin configuration and service permissions are required for reliable operation.