Azure Monitor vs Prometheus: What are the differences?

Azure Monitor and Prometheus are both monitoring solutions. Here are the key differences between them.

1. Scalability: One major difference between Azure Monitor and Prometheus is their scalability. Azure Monitor is a fully managed service provided by Microsoft, which means it can automatically scale to handle large workloads without any manual intervention. On the other hand, Prometheus is an open-source monitoring tool that requires manual scaling as the workload increases.

2. Data Collection: Azure Monitor offers a wide range of data collection methods, including agents, APIs, and platform integrations. It can collect data from various sources such as virtual machines, containers, and Azure services. In contrast, Prometheus primarily collects data using its own built-in client libraries, requiring application owners to instrument their code to expose metrics.

3. Alerting: Azure Monitor provides advanced alerting capabilities, allowing users to create alert rules based on metrics, logs, and events. It also supports various notification channels such as email, SMS, and webhooks. Prometheus also supports alerting, but its alerting system is less robust compared to Azure Monitor. It has limited built-in notification options and relies heavily on external alert managers for advanced alert management and routing.

4. Dashboards: Azure Monitor offers a user-friendly dashboarding experience with drag-and-drop capabilities and a wide range of visualization options. It provides pre-built dashboards for monitoring Azure resources and also allows users to create custom dashboards. Prometheus, on the other hand, provides a basic web interface for data visualization, but it primarily focuses on exposing data via its query language and relies on external tools for more advanced dashboarding capabilities.

5. Integration with Ecosystem: Azure Monitor is tightly integrated with the Microsoft Azure ecosystem, making it an ideal monitoring solution for organizations using Azure services. It provides out-of-the-box integration with various Azure services, including Virtual Machines, Azure Kubernetes Service, and Azure Functions. Prometheus, being an open-source tool, is more agnostic and can be used with any infrastructure or cloud provider. It has integrations for various platforms and services, including Kubernetes, AWS, and GCP.

6. Pricing Model: Azure Monitor has a usage-based pricing model, where users pay for the data ingested and the features they use. It offers different pricing tiers with varying levels of functionality and scalability. Prometheus, on the other hand, is open-source and free to use. However, there may be additional costs associated with running Prometheus at scale, such as storage costs for the collected metrics and the infrastructure required for running Prometheus servers.

In summary, Azure Monitor is a fully managed service with auto-scaling capabilities, comprehensive data collection methods, advanced alerting and dashboarding features, tight integration with Azure services, and a usage-based pricing model. On the other hand, Prometheus is an open-source tool that requires manual scaling, primarily collects data through client libraries, has limited built-in alerting and dashboarding capabilities, and can be used with various platforms and services.