Blog
Engineering notes, practical monitoring guides and product updates from the team behind m0nitor.
Which DNS failures actually take sites down, which records to watch (A, AAAA, CNAME, MX, NS), how often to check them and how to alert on them.
Rotation models for teams of 2 to 8, a handover checklist, holiday overrides, do-not-disturb hours and a simple rule for which alerts wake someone up at night.
A 502 means your proxy could not get a valid response from the upstream. Here is how to find which cause you have, with log lines, commands and monitoring checks.
How to structure components, define honest status levels, pace incident updates, announce maintenance and host your status page so it stays up when you are down.
A TCP port check tells you something is listening, not that it works. Here is when to use one, how to set timeouts and how to layer it with HTTP and app-level checks.
A practical check sequence to tell a local DNS, ISP or browser issue from a real outage, read multi-country results correctly and decide when to open an incident.
False alarms train your team to ignore pages. Here is how to cut them with multi-region confirmation, retries, timeouts based on real latency and split thresholds.
Exact downtime budgets for 99% to 99.99% uptime per day, month and year, plus how check intervals, maintenance windows and dependencies change what you can promise.
A practical structure for incident status updates: what is affected, what users should do, when the next update comes, plus templates for each stage and common mistakes.
Auto-renewal does not stop certificates from expiring. Here is why renewals fail, which warning thresholds make sense and what to check beyond the expiry date.
Cron jobs fail without a sound: no output, no exit code, no alert. This guide covers heartbeat pings, grace periods, wrapper scripts and alert routing.