Prometheus Scaling with Thanos

Introduction

Scaling Prometheus can be challenging, especially in large environments. Thanos provides an elegant solution for scaling and long-term storage of Prometheus metrics by enabling a global view of your metrics data.

Key Concepts

• **Thanos**: A set of components that can be added to Prometheus to enable long-term storage, global querying, and high availability.
• **Store Gateway**: A Thanos component that allows querying of historical data stored in object storage.
• **Compactor**: Merges and compacts the historical data, optimizing storage efficiency.
• **Query Layer**: Provides a unified view for querying metrics across multiple Prometheus instances.

Setup Steps

Follow these steps to set up Thanos with Prometheus:

1. **Install Thanos**: Download and install Thanos from the official GitHub repository.
2. **Start Prometheus with Thanos Sidecar**: Add the Thanos sidecar to your Prometheus configuration.

   # prometheus.yml
                   rule_files:
                     - "alerts.yml"
                     - "rules.yml"
                   scrape_configs:
                     - job_name: 'thanos'
                       static_configs:
                         - targets: ['localhost:9090']
                   

3. **Run Thanos Sidecar**: Use the following command to start the sidecar:

thanos sidecar \
                  --tsdb.path=/path/to/prometheus/data \
                  --http-address=0.0.0.0:19100 \
                  --grpc-address=0.0.0.0:19090 \
                  --objstore.config-file=/path/to/bucket.yaml
                

4. **Deploy Thanos Store Gateway**: Use the following command to deploy the Store Gateway:

thanos storegateway \
                  --objstore.config-file=/path/to/bucket.yaml \
                  --http-address=0.0.0.0:19080
                

5. **Run the Thanos Query Layer**: Start the Query component:

thanos query \
                  --http-address=0.0.0.0:9090 \
                  --grpc-address=0.0.0.0:9091 \
                  --store=dnsa://store-gateway:19080
                

Best Practices

Here are some best practices when using Thanos with Prometheus:

• Use **external storage** for long-term data retention.
• Regularly monitor the **compaction and retention** settings to optimize performance.
• Set up **alerts** on critical metrics to maintain observability.
• Implement **RBAC (Role-Based Access Control)** for secure access to metrics.

FAQ