Long running connection getting dropped without proper handling

I have an express server, responding to API calls.

Before calling server.listen() I initialise the Query Builder, and leave it running in the background

It all works fine until after an arbitrary amount of time passes and I get this

events.js:167
      throw er; // Unhandled 'error' event
      ^
Error: Connection lost: The server closed the connection.
    at Protocol.end (/data/darends/artron/backend/node_modules/mysql/lib/protocol/Protocol.js:112:13)
    at Socket.<anonymous> (/data/darends/artron/backend/node_modules/mysql/lib/Connection.js:97:28)
    at Socket.<anonymous> (/data/darends/artron/backend/node_modules/mysql/lib/Connection.js:502:10)
    at Socket.emit (events.js:187:15)
    at endReadableNT (_stream_readable.js:1094:12)
    at process._tickCallback (internal/process/next_tick.js:63:19)
Emitted 'error' event at:
    at Connection._handleProtocolError (/data/darends/artron/backend/node_modules/mysql/lib/Connection.js:425:8)
    at Protocol.emit (events.js:182:13)
    at Protocol._delegateError (/data/darends/artron/backend/node_modules/mysql/lib/protocol/Protocol.js:390:10)
    at Protocol.end (/data/darends/artron/backend/node_modules/mysql/lib/protocol/Protocol.js:116:8)
    at Socket.<anonymous> (/data/darends/artron/backend/node_modules/mysql/lib/Connection.js:97:28)
    [... lines matching original stack trace ...]
    at process._tickCallback (internal/process/next_tick.js:63:19)

Note: This occurs when using single or pool (even with qb.release())

On researching how mysqljs/mysql handles its fatal errors,

If a fatal errors occurs and there are no pending callbacks, or a normal error occurs which has no callback belonging to it, the error is emitted as an 'error' event on the connection object. This is demonstrated in the example below:

Query Builder does not expose anything which would allow me to either catch or handle the error

mysql suggests this method.

connection.on('error', function(err) {
  console.log(err.code); // 'ER_BAD_DB_ERROR'
});

I was wondering if either

• this .on method is able to be exposed
• in the config, pass a callback which is automatically attached this listener

[rohit-gh]

@kylefarris
I'm facing this error as well, any updates on this?
can we have a error handler API exposed like :

let qb = pool.get_connection();
 qb.on('error', async (err) => {
   // handle errors.
})