ProxySQL

ProxySQL sits between applications and MySQL-compatible backends, routing reads and writes, caching query results, and failing over automatically when a backend goes down. It is protocol-aware, meaning it can inspect and rewrite SQL as it passes through, which makes it a common choice for sharding, query firewalling, and connection multiplexing at scale.

It supports native replication topologies, Group Replication, and Galera, and integrates with Orchestrator and its own admin interface for runtime reconfiguration without restarts.