Reconnect logic on connection close in X DevAPI of MySql using @mysql/xdevapi module in Node.js

Question

I am using X DevAPI of MySql v8.0.33 using @mysql/xdevapi v8.0.33.

I have reconnect logic added but that is not working. Here is that code.

const mysqlx = require('@mysql/xdevapi')

async function createSession() {
  try {
    const session = await mysqlx.getSession({
      user: 'your_user',
      password: 'your_password',
      host: 'your_host',
      port: 33060, // default MySQL X Protocol port
    });

    // Handle connection close by reconnecting the session
    session['_client']['_stream'].on('close', () => {
      console.log('Connection closed. Reconnecting...');
      createSession(); // Re-establish the session
    });

    // Use the session for your database operations
    // ...

  } catch (error) {
    console.error('Error connecting to MySQL:', error);
  }
}

// Create the initial session
createSession();

I am getting error

TypeError: Cannot read properties of undefined (reading '_stream')

This error means that session['_client'] is undefined.

What is wrong with my reconnect logic?

Answer 1

As you mention, session['_client'] is not defined nor available. I guess you can get a socket reference with session.getConnection_().getClient().getConnection(), however this is an internal API and is prone to breaking changes without notice, so I would probably not recommend it. Instead, you can have some kind of decorator that wraps your workflows and creates a connection if one is not available.

Disclaimer: I'm the lead developer of the MySQL X DevAPI Connector for Node.js