Thanos Sidecar
Thanos Sidecar is the most fundamental Thanos component, enabling Thanos’s two most popular features: querying multiple Prometheus instances from a centralized location (Thanos Query) and backing up Prometheus TSDB data in an object storage backend.
Thanos Sidecar works by running alongside the Prometheus server as a “sidecar” (clever naming, huh?). This is technically only a strict requirement if you’re using the sidecar to upload Prometheus data to object storage, but you should strive to deploy the Sidecar alongside your Prometheus instance, even if you don’t use that feature. Doing so will help minimize latency between the Sidecar and Prometheus.
The Sidecar fulfills its first job of enabling distributed querying of Prometheus instances by exposing a gRPC API that Thanos Query (or other Thanos components such as Ruler) can communicate with. This gRPC API (henceforth referred to as StoreAPI) is implemented and exposed by the...
