How to use top to monitor a server's performance.
This guide shows how to install and configure Graylog2, a log management and analysis tool with Elasticsearch and MongoDB, on Debian 9 server.
Improve uptime with Monit Server Monitoring. Monit will watch you system around the clock, and respond to out-of-the-norm events by following your instructions.
Use the vmstat tool to monitor your system's virtual memory usage.
This guide provides an introduction to the installation and basic setup of Graphite together with Grafana on Ubuntu 14.04.
Use Logwatch to generate digests and analyze your server logs
Nagios is a widely used tool for monitoring systems and services.