Thanos is a distributed metrics query engine and monitoring scalability suite designed to provide a unified interface for aggregating data from multiple Prometheus servers and clusters. It functions as a high availability monitoring backend that eliminates single points of failure by deduplicating data from replicated instances.
The system enables long-term retention by persisting time-series data to cloud-native object storage, allowing for unlimited historical archiving beyond the limits of local disks. It further optimizes this storage through a downsampling and retention manager that compresses historical data to reduce costs and accelerate query speeds.
The project covers broad capability areas including cross-cluster metric federation, stateless query execution, and automated data compaction. It also includes mechanisms for alert and recording rule evaluation and fault-tolerant query routing across distributed nodes.