In the world of cloud-native applications, monitoring and observability have become crucial components of maintaining system health and performance. Prometheus has emerged as a leading open-source solution for monitoring and alerting, offering a powerful query language and a robust ecosystem. However, as organizations scale, they often encounter limitations with Prometheus’s storage capabilities. This is where Mimir, an open-source project from Grafana Labs, comes into play. Mimir provides a horizontally scalable, multi-tenant, long-term storage solution for Prometheus metrics. In this article, we’ll explore how to write data from Prometheus to Mimir, enhancing your monitoring stack’s scalability and reliability.

Understanding Prometheus and Mimir

Prometheus

Prometheus is a time-series database designed for real-time monitoring and alerting. It scrapes metrics from configured endpoints at specified intervals, evaluates rule expressions, displays results, and triggers alerts if certain conditions are met. While Prometheus is excellent for short-term storage and real-time querying, its local storage is not designed for long-term retention or high availability.

Mimir

Mimir is an open-source project that extends Prometheus’s capabilities by providing a scalable, long-term storage solution. It is built on top of Cortex, another open-source project, and offers features like multi-tenancy, high availability, and horizontal scalability. Mimir allows you to store and query Prometheus metrics over a much longer period, making it ideal for large-scale deployments.

Setting Up Mimir

Before you can write data from Prometheus to Mimir, you need to set up a Mimir instance. Here’s a high-level overview of the steps involved:

1. Install Mimir: You can deploy Mimir using Docker, Kubernetes, or directly on a virtual machine. Grafana Labs provides detailed installation instructions for each method.

2. Configure Storage Backend: Mimir supports various storage backends, including AWS S3, Google Cloud Storage, and local filesystems. Choose a backend that suits your needs and configure Mimir to use it.

3. Configure Mimir: Edit the Mimir configuration file to set up the desired retention policies, authentication, and other settings. Ensure that Mimir is accessible from your Prometheus server.

Writing Data from Prometheus to Mimir

Once Mimir is set up, you can configure Prometheus to write data to it. This involves setting up a remote write configuration in Prometheus. Here’s how you can do it:

1. Edit Prometheus Configuration: Open your prometheus.yml configuration file and add the following under the remote_write section:

   remote_write:
     - url: "http://<mimir-instance-url>/api/v1/push"
       basic_auth:
         username: "<your-username>"
         password: "<your-password>"
   

   Replace <mimir-instance-url>, <your-username>, and <your-password> with your Mimir instance’s URL and authentication credentials.

2. Restart Prometheus: After updating the configuration, restart your Prometheus server to apply the changes.

3. Verify Data Ingestion: Use Grafana or another visualization tool to query Mimir and verify that data is being ingested correctly.

Benefits of Using Mimir with Prometheus

• Scalability: Mimir’s architecture allows you to scale horizontally, accommodating growing data volumes without sacrificing performance.
• Long-term Storage: Store metrics for months or years, enabling historical analysis and trend forecasting.
• High Availability: Mimir’s distributed nature ensures that your metrics are available even in the event of node failures.
• Multi-tenancy: Support for multiple tenants allows you to isolate data and access for different teams or projects.

Conclusion

Integrating Prometheus with Mimir provides a robust solution for organizations looking to scale their monitoring infrastructure. By offloading long-term storage to Mimir, you can focus on real-time monitoring with Prometheus while benefiting from Mimir’s scalability and reliability. As your infrastructure grows, this combination ensures that you maintain visibility into your systems’ performance and health.

For more detailed instructions and best practices, consider exploring the official documentation for Prometheus and Mimir.

By leveraging these open-source tools, you can build a powerful, scalable monitoring solution that meets the demands of modern cloud-native environments.