> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pg-sharding.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Coordinator

The coordinator consists of two parts: the coordinator itself and the QDB.

* The **SPQR Coordinator** provides an interface for managing a sharded cluster configuration and routers.
* **QDB** stores the metadata for a sharded cluster, which includes the distributions, key ranges, tables, distributed locks, and so on. It's a regular etcd cluster ([https://etcd.io](https://etcd.io))