Alertmanager

As explained in Cloud Observability in Action

Alertmanager is a Prometheus component that groups, routes, silences, and suppresses alerts.

Alertmanager is the notification layer for Prometheus alerting. Prometheus evaluates PromQL alert conditions and sends firing alerts to the Alertmanager API, which processes them before delivery. section 7.2.1

Alertmanager reduces operational noise by handling several notification tasks:

• Deduplicates repeated alerts and groups related alerts into concise notifications. section 7.2.1
• Routes alerts through policies, such as sending work-hour notifications to Slack and after-hours notifications by text message. section 7.2.1
• Suppresses notifications when appropriate and delivers them through configured receivers, including webhooks or email. section 7.2.1 section 7.4

Prometheus to webhook

A Prometheus rule fires when API requests exceed 40 and labels the alert critical. Prometheus sends it to Alertmanager, whose route groups alerts by environment and forwards them to a configured webhook. A Docker Compose setup can run Prometheus, Alertmanager, and a webhook endpoint together. section 7.2.1

Figure 7.2 Prometheus and the Alertmanager

Use the architecture diagram to follow the path from scraped metrics and Prometheus rules through Alertmanager to operator notifications. section 7.2.1

How Cloud Observability in Action covers it

How deep it goes

Explains the Prometheus handoff and demonstrates routing configuration, but does not detail Alertmanager internals.

Examples

Uses a critical API-call alert, environment-based grouping, webhook delivery, Docker Compose, and operator notifications.

What it assumes

Assumes familiarity with Prometheus metrics and alerting while showing the Prometheus-to-Alertmanager workflow concretely.

What you can do after

Operate/configure Alertmanager to route concise Prometheus notifications and reduce alert fatigue.

How it connects

Connects Prometheus, PromQL, alerting rules, receivers, webhooks, email, Slack, and Grafana.

liveBookmanning.com

Read Cloud Observability in Action on liveBook Get the book at manning.com

Also explained in

• 

  liveBookmanning.com
  Machine Learning Platform EngineeringAlertmanager is the Prometheus component that groups, routes, and delivers alerts to notification channels.
• 

  liveBookmanning.com
  ScyllaDB in ActionAlertmanager is an open-source service in the Prometheus ecosystem that groups, routes, and delivers alert notifications.

Compare how 3 books explain Alertmanager →

Related concepts

• alertinguses · Alerting is the generation and delivery of notifications when monitored conditions or events meet defined criteria or require attention or action.
• Prometheusused by · Prometheus is an open-source monitoring and alerting system that collects, stores, and queries time-series metrics.
• monitoring stackpart of · A monitoring stack is a coordinated collection of tools that collects, stores, analyzes, visualizes, and alerts on operational system telemetry.

This explainer was generated by Manning's knowledge graph from the text of Cloud Observability in Action. The section links point to the parts of the book it draws on.