Observability with Prometheus and Grafana

Choosing Between Prometheus and Grafana for Alerting

Selecting the right alerting tool depends on the scale of your infrastructure, your monitoring goals, and how deeply you need to customize alerting rules.

Prometheus Alerting with Alertmanager

Prometheus, paired with Alertmanager, is well-suited for large-scale, high-cardinality monitoring environments such as Kubernetes clusters and microservices architectures. Prometheus’s query language, PromQL, enables highly customizable and precise alert definitions, making it ideal for advanced users who require fine-grained control.

As a reminder, here are some of the key features and advantages of using Prometheus with Alertmanager:

• Integration with multiple notification platforms: Alertmanager supports sending alerts via Slack, PagerDuty, email, and custom webhooks.
• Flexible alert routing and deduplication: You can define alert routes, silence alerts, and group notifications to reduce alert fatigue.
• Decoupled from visualization: Unlike Grafana, alerts in Prometheus are independent of dashboards, making it better suited for infrastructure-wide monitoring.

However, Prometheus lacks built-in dashboarding capabilities, so it’s often paired with Grafana for visualization. Integrating Prometheus with Grafana combines robust alerting and powerful visualization for a complete monitoring setup.

Grafana Alerting with Built-in Alertmanager

Grafana offers integrated alerting that’s tied to its dashboards. For teams focused on visualizing and monitoring specific metrics, Grafana is an attractive choice-its intuitive UI makes alert creation straightforward, even for users with limited experience writing PromQL queries.

Here is a summary of the advantages and limitations of Grafana’s built-in alerting:

• Dashboard-based alerts: Alerts are defined within panels on Grafana dashboards, making them ideal for visualization-centric monitoring.
• User-friendly interface: Grafana provides a simple UI for creating and managing alerts without requiring complex queries.
• Multi-source compatibility: It works with multiple data sources, including Prometheus, Loki, and Elasticsearch, offering broad integration flexibility.
• Limited scalability: Grafana’s alerting system lacks shared templates, meaning alerts must often be redefined across dashboards. In contrast, Prometheus stores alert rules in YAML files, separate from dashboards, allowing version control and reuse across environments (e.g., with Helm or Terraform).

Choosing Between the Two

For large-scale deployments, Prometheus with Alertmanager is the stronger choice due to its scalability, configurability, and mature alert management.

For smaller teams or visualization-first workflows, Grafana’s built-in alerting may be sufficient, providing simplicity and ease of use without the complexity of managing a full Prometheus + Alertmanager stack.

Using both at the same time could be an alternative approach, but the main drawback is the increased complexity of managing two sources of truth for alerts. This can lead to confusion in incident response and alert fatigue if not carefully coordinated.

The table below serves as a set of quick heuristics to help you decide which alerting setup best fits your use case. It maps common questions or needs to the most appropriate alerting configuration, along with clear reasoning for each recommendation.