Alertmanager Guide for the Monitoring Stack¶

Alertmanager receives alerts from Prometheus and decides how they should be grouped, routed, silenced, and repeated.

What It Handles¶

• Grouping related alerts
• Routing alerts to the right destination
• Silencing planned maintenance noise
• Preventing duplicate or unnecessary notifications

A Practical Routing Model¶

• Group alerts by service, team, or severity
• Send critical alerts immediately
• Batch warning alerts to reduce noise
• Silence known maintenance windows

Good Routing Ideas¶

• Infrastructure alerts to the platform team
• Probe failures to the owning service team
• Low-severity alerts to email or chat summaries
• High-severity alerts to paging tools

Useful Concepts to Add Over Time¶

• group_by
• group_wait
• group_interval
• repeat_interval
• Inhibition rules
• Receiver-specific routes

Practical Advice¶

• Avoid paging for every single alert
• Keep severity labels consistent in Prometheus rules
• Test routes before relying on them in incidents

Quick Check¶

docker compose logs -f alertmanager
curl http://localhost:9093/-/healthy