pg-protocol throws an uncatchable error when it loses the connection to PostgreSQL server via TLS

[yuk2521]

When the PostgreSQL server gets terminated, an uncatchable error is thrown from pg-protocol with following message

error: terminating connection due to administrator command
    at Parser.parseErrorMessage (/xxx/node_modules/pg-protocol/dist/parser.js:287:98)
    at Parser.handlePacket (/xxx/node_modules/pg-protocol/dist/parser.js:126:29)
    at Parser.parse (/xxx/node_modules/pg-protocol/dist/parser.js:39:38)
    at TLSSocket.<anonymous> (/xxx/node_modules/pg-protocol/dist/index.js:11:42)
    at TLSSocket.emit (node:events:526:28)
    at addChunk (node:internal/streams/readable:315:12)
    at readableAddChunk (node:internal/streams/readable:289:9)
    at TLSSocket.Readable.push (node:internal/streams/readable:228:10)
    at TLSWrap.onStreamRead (node:internal/stream_base_commons:190:23)

It seems that the errors in the on stream data listener here is not handled properly?

node-postgres/packages/pg-protocol/src/index.ts

Line 7 in 9a95ee7

stream.on('data', (buffer: Buffer) => parser.parse(buffer, callback))

[charmander]

node-postgres/packages/pg/lib/connection.js

Lines 47 to 62 in 9a95ee7

	const reportStreamError = function (error) {
	// errors about disconnections should be ignored during disconnect
	if (self._ending && (error.code === 'ECONNRESET' || error.code === 'EPIPE')) {
	return
	}
	self.emit('error', error)
	}
	this.stream.on('error', reportStreamError)
	this.stream.on('close', function () {
	self.emit('end')
	})
	if (!this.ssl) {
	return this.attachListeners(this.stream)
	}

It’s not uncatchable. You need to add an error listener to any pools and clients you use.

[charmander]

Canonical issue for improving error ergonomics: #2439 (comment)

[yuk2521]

Hi @charmander

I'm pretty sure I've added the error listener on the pool as follows

  pool.on('error', (err, client) => {
    logger.error(`Unexpected error on idle client ${client}: ${err}`);
  });

and, all queries are emitted though pool.query. But, still, the error was not caught and the app crashed.

Do you mean the error thrown from the data listener should be caught by the error listener? I've tested with the following example and it fails to catch the error.

const stream = Readable.from(['hi pg']);
stream.on('error', () => {
  console.log('error caught');
});
stream.on('data', () => {
  throw new Error('some error');
});

It produces the error:

$ node main.js
file:///xxx/main.js:8
  throw new Error('some error');
  ^

Error: some error
    at Readable.<anonymous> (file:///xxx/main.js:8:9)
    at Readable.emit (node:events:527:28)
    at Readable.read (node:internal/streams/readable:527:10)
    at flow (node:internal/streams/readable:1011:34)
    at resume_ (node:internal/streams/readable:992:3)
    at processTicksAndRejections (node:internal/process/task_queues:83:21)

[yuk2521]

Canonical issue for improving error ergonomics: #2439 (comment)

Oh, sorry that I missed this information.

I'll try again with error listeners added to all the connected clients.

Update:
It now works! Thanks for you support @charmander