Observability, monitoring and alerting tools in one directory, from the metrics store to the phone that rings at 3am. Open source and commercial, side by side, with free plans and self-hosting marked.
Understand what a system is doing from its telemetry: metrics, logs, traces, profiles and errors.
Check that services, hosts, networks and scheduled jobs are up and healthy, from inside and outside.
All 151 monitoring toolsGet the right person to the problem: routing, notifications, on-call, incident response and status pages.
All 92 alerting toolsEvery listing checked by hand. Last checked 30 September 2026.
How an alert moves from a monitoring tool to a person, and on to the next person when nobody acknowledges.
Levels, waits, targets and repeats in an escalation policy, with example policies, common mistakes and a checklist.
Weekly, daily, primary and secondary, and follow the sun: the common on-call rotation patterns and when each fits.
How to define severity levels by user impact, what each level should trigger, and how severity connects to paging.
Page on symptoms, not causes: the four golden signals, RED and USE, checks from outside, and what makes an alert worth a page.
Why teams stop trusting their alerts, how to measure the noise, and the fixes: delete, wait, group, inhibit, route by urgency and review.
How heartbeat monitoring catches cron jobs that silently stop, and how to set the period and grace time.
SLIs, SLOs and error budgets, and how multiwindow burn-rate alerts page on real risk to users.
What happens after someone acknowledges: declaring an incident, the roles, communication, and the blameless postmortem.
What MTTD, MTTA, MTTR and MTBF measure, where each clock starts and stops, and how to use them without gaming them.
The questions that separate on-call tools: notification methods, schedules, alert sources, pricing, self-hosting, and a short trial plan.
Learn how Alertmanager deduplicates, groups, and routes alerts using matchers, timers, and inhibition rules.
Learn how dedup keys, grouping, and flap handling reduce noise in PagerDuty, Opsgenie, and Alertmanager with concrete field examples.
Compare silences, maintenance windows, inhibition and snooze. Learn Alertmanager commands and a checklist to mute alerts without missing outages.
On-call handover checklist and template for SREs to pass pager context, open incidents, and risks to the next shift.
Learn when to use overrides, swaps, or rotation edits. Compare PagerDuty, Opsgenie, and Grafana IRM. Get clear rules for sick days and approvals.
How to test an escalation policy before a real outage. Check contacts, send a test alert, and walk every level to verify your on-call setup.
Learn how PagerDuty, Opsgenie, Grafana IRM and Prometheus Alertmanager handle alert lifecycle states: triggered, acknowledged and resolved.
Learn the PagerDuty Events API v2 format. See required fields, dedup_key logic, and a curl example for triggers and resolves.
Choose alert notification channels: push, SMS, voice, email and chat. Learn delivery, cost, and DND rules for on-call reliability.
Rules for writing alert titles and bodies that tell engineers what broke, who owns it, and what to do first.
How to split incident work across the commander, communications lead and scribe roles, with PagerDuty and Google practice, handoffs and role cards.
A clear runbook structure, linking from Prometheus or Grafana, and practical habits to keep documentation current and useful for on-call engineers.
Learn to write blameless postmortems with a template. Covers triggers, timeline building, and action items to fix systems and prevent repeat incidents.
How to write clear status page updates during an incident, with templates for each state, a default cadence and component statuses.
The books, handbooks and essays that most on-call and observability practice comes from, most of them free to read online. See the reading list.
MTTA, dead man's switch, burn rate, flapping: the vocabulary of monitoring and alerting on one page. Open the glossary.
