miantalha45 opened a new issue, #17179: URL: https://github.com/apache/iotdb/issues/17179
### Search before asking - [x] I searched in the [issues](https://github.com/apache/iotdb/issues) and found nothing similar. ### Motivation I am always frustrated when the IoTDB CLI exits as soon as the connection to the server is lost (e.g. server restart, network blip, or idle timeout). I have to reconnect manually, re-enter connection parameters, and lose my session context. Other IoTDB clients already support reconnection: the Session API (Java), JDBC (via callWithRetryAndReconnect in IoTDBStatement), and the C++/Python clients all retry and reconnect on connection failure. The CLI is the only major client that does not—it holds a single connection for the entire interactive session and exits on any connection-related error. Adding automatic reconnection to the CLI would align its behaviour with the rest of the client stack and improve the experience for long-lived interactive sessions (e.g. over SSH or after server restarts). ### Solution **Proposed behaviour** 1. **Detect connection loss** When a command fails with a connection-related error (e.g. SQLException caused by connection refused, timeout, or closed connection), do not exit immediately. 2. **Attempt reconnection** Try to establish a new connection using the same parameters (host, port, user, password, and options) that were used at login. Reuse the same logic as the initial connection (e.g. DriverManager.getConnection with the same URL and properties). 3. **Retry the command** After a successful reconnection, retry the same user command (the current line/statement that failed) with the new connection, with a bounded number of retries (e.g. 3) and optional backoff. 4. **User feedback** On successful reconnection, print a short message such as: "Connection lost. Reconnected. Retrying command." and continue the interactive loop with the new connection. 5. **Failure handling** If reconnection fails after all retries, exit with a clear error message, e.g. "Could not reconnect after N attempts. Please check that the server is running and try again." **Relevant code** - `iotdb-client/cli/src/main/java/org/apache/iotdb/cli/Cli.java`: - `receiveCommands()` opens one connection and runs a `while (true)` loop; any SQLException is caught at the top level and the process exits (lines 215–217). - Change: catch connection-related failures inside the loop (or around `processCommand`), attempt reconnection, then retry the command or continue with the new connection. - `iotdb-client/jdbc`: - `IoTDBConnection.reconnect()` and `IoTDBStatement.callWithRetryAndReconnect()` can be used as reference for retry/reconnect behaviour. **Optional** - Make retry count and interval configurable (e.g. CLI options or environment variables) for consistency with Session/JDBC. ### Alternatives 1. **No retry, only reconnect** On connection loss, attempt reconnection and, on success, continue the session without retrying the failed command (user re-enters it). Simpler to implement but less convenient than retrying the last command. 2. **Prompt user** On connection loss, prompt: "Connection lost. Reconnect? (y/n)". If yes, reconnect and optionally retry the command. Gives control but adds friction for automated or scripted use. 3. **Leave as-is** Keep current behaviour (exit on connection loss). This preserves simplicity but leaves the CLI as the only client without reconnection support and worsens UX for long sessions and unstable networks. ### Are you willing to submit a PR? - [x] I'm willing to submit a PR! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
