Knowing the state of your server before someone else tells you.
WHAT TO MONITOR
Availability: is the server responding
Service status: are web, database and mail running
CPU, memory and disk usage Disk space, which fills silently and breaks everything Load average Network traffic Certificate expiry
TOOLS
External uptime monitoring, which checks from outside and alerts you when the site stops responding. Free tiers are adequate. On-server monitoring tools reporting resource usage over time. Control panel dashboards, where you run one.
WHY EXTERNAL MONITORING MATTERS MOST
If the server is down, on-server monitoring is down too. An external service is the one that tells you.
ALERTING
Alerts must reach you somewhere you will see them, not an email address on the server that is down.
Use an address elsewhere, and consider SMS or a messaging integration for critical alerts.
WHAT TO ALERT ON
Site unreachable Disk above eighty per cent Memory exhausted A service stopped
Alert on things requiring action. Alerting on everything trains you to ignore alerts.
