end msg to unopened socket

[roccomuso]

node-postgres/lib/connection.js

Lines 315 to 322 in 060a35f

	Connection.prototype.end = function () {
	// 0x58 = 'X'
	this.writer.add(emptyBuffer)
	this._ending = true
	return this.stream.write(END_BUFFER, () => {
	this.stream.end()
	})
	}

pg module tries send end message and don't consider if socket is open, app will hang.

[charmander]

That code isn’t right (see #1386 (comment)), but what will hang?

[fanatid]

const pg = require('pg')

;(async () => {
  console.time('time')
  process.on('exit', () => console.timeEnd('time'))

  // connect to PG server which available only through VPN over UDP
  const client = new pg.Client({ connectionString: '...' })
  client.on('error', (err) => console.log(err))

  const tid = setTimeout(() => {
    console.log('timeout!')
    // client.end()
    // client.connection.stream.destroy()
  }, 1000)

  await client.connect()
  console.log('connected')
  clearTimeout(tid)

  client.end()
})().catch((err) => {
  console.error(err.stack || err)
  process.exit(1)
})

with client.connection.stream.destroy():

time node ./pg-end-bug.js 
timeout!
Error: Connection terminated unexpectedly
  ....
time: 1016.979ms

real	0m1.132s
user	0m0.115s
sys	0m0.019s

with client.end():

time node ./pg-end-bug.js 
timeout!
Error: connect ETIMEDOUT 10.130.14.135:5432
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1121:14)
time: 129074.137ms

real	2m9.185s
user	0m0.107s
sys	0m0.020s

[charmander]

So the request is for client.end() to cancel pending connections as well?

[fanatid]

Sorry for unclear description for example.
Yes, issue about pending connection, currently .end() do not terminate connection and as result process will be alive up to 120s (default timeout value in node).

[fanatid]

Writing to such socket do not throw error on node@12.3.1. PR #1847 partially solve this problem.