# Diagnose remote SQL connection timeouts

Coordinator DB does not provide `remote()` or `remoteSecure()` SQL table functions. A remote query uses a client connection to the documented native or HTTP interface. Diagnose the connection from the host that actually sends the request.

## Identify when it times out

A timeout before connection establishment points to address resolution, routing, firewall rules or the listener. A receive timeout after sending request bytes can involve transport limits or a slow client. A SQL execution-limit error is reported by the database and has a different scope.

For native access, pass the complete host and port to `coordinator client --addr`. For HTTP, test `/ping` and a small authenticated SELECT before running the workload. External TLS protection, if present, adds a separate handshake stage.

## Compare the relevant limits

Server `request_read_timeout` controls socket receive behavior. `max_execution_time` bounds SQL processing. The application's own timeout controls how long it waits; it does not cancel the server-side request. Server-side cancellation is unsupported.

If a timed-out operation writes data, reconcile the destination before repeating it. Keep the endpoint, failing stage, duration and query identifier when available. Raising all timeouts together hides which stage needed attention.

See [native client](https://coordinatordb.com/docs/concepts/features/interfaces/client), [HTTP interface](https://coordinatordb.com/docs/concepts/features/interfaces/http) and [server limits](https://coordinatordb.com/docs/reference/settings/server-settings/settings/max).