Server Monitoring with Icinga: Preventing Outages

Icinga is an open-source monitoring system that originated from the Nagios project. It checks at configurable intervals whether services are reachable and functional. When deviations occur, Icinga sends alerts via email, Slack, SMS or other channels.

The Icinga Web 2 interface visualizes the status of all monitored systems in a dashboard. Historical data shows trends and helps predict capacity bottlenecks.

HTTP availability. Is the website reachable? Does it return the correct status code? How long does the response take?

SSL certificates. When does the certificate expire? Icinga warns in time so renewal is not forgotten.

Disk space. Full disks are a common cause of outages. Icinga warns before storage runs low.

PHP processes. Are enough PHP workers available? Are processes running in infinite loops? Icinga detects abnormal behavior.

Database. Is MySQL/MariaDB reachable? How high is the utilization? Are there slow queries costing performance?

Cron jobs. Are Drupal cron tasks running regularly? Failing cron jobs lead to stale caches and missing indexing.

Monitoring without response is worthless. What matters is that alerts go to the right people and defined escalation levels take effect. arocom configures monitoring rules so that critical alerts arrive immediately and informational warnings are collected.

The goal is not zero alerts — the goal is zero unnoticed problems.

arocom sets up monitoring as part of hosting operations. The Future Check evaluates your current monitoring. Starting at EUR 2,500 plus VAT, credited toward the follow-up project.