Error: send 111

I’m getting an obscure “send 111” error when trying to log using the unix protocol. Any ideas? The node-syslog package works fine, as does using logger at the command line.

var winston = require('winston');
require('winston-syslog').Syslog;
winston.add(winston.transports.Syslog, {protocol:'unix',path:'/dev/log'});
winston.debug('hi')
debug: hi
Error: send 111
  at errnoException (/home/gwarner/winston-syslog/node_modules/unix-dgram/src/unix_dgram.js:25:11)
  at Socket.send (/home/gwarner/winston-syslog/node_modules/unix-dgram/src/unix_dgram.js:75:24)
  at /home/gwarner/winston-syslog/lib/winston-syslog.js:158:21
  at [object Object].Syslog.connect (/home/gwarner/winston-syslog/lib/winston-syslog.js:200:9)
  at [object Object].Syslog.log (/home/gwarner/winston-syslog/lib/winston-syslog.js:131:8)
  at [object Object].Logger.log (/home/gwarner/winston-syslog/node_modules/winston/lib/winston/logger.js:182:17)
  at Object.winston.(anonymous function) [as log] (/home/gwarner/winston-syslog/node_modules/winston/lib/winston.js:82:34)
  at Object.target.(anonymous function) [as debug] (/home/gwarner/winston-syslog/node_modules/winston/lib/winston/common.js:44:21)
  at repl:1:13
  at REPLServer.replDefaults.eval (/usr/lib/node_modules/coffee-script/lib/coffee-script/repl.js:33:42)
  at repl.js:239:12
  at Interface.<anonymous> (/usr/lib/node_modules/coffee-script/lib/coffee-script/repl.js:64:9)
  at Interface.emit (events.js:117:20)
  at Interface._onLine (readline.js:202:10)
  at Interface._line (readline.js:531:8)
  at Interface._ttyWrite (readline.js:760:14)
  at ReadStream.onkeypress (readline.js:99:10)
  at ReadStream.emit (events.js:117:20)
  at emitKey (readline.js:1095:12)
  at ReadStream.onData (readline.js:840:14)
  at ReadStream.emit (events.js:95:17)
  at ReadStream.<anonymous> (_stream_readable.js:748:14)
  at ReadStream.emit (events.js:92:17)
  at emitReadable_ (_stream_readable.js:410:10)
  at emitReadable (_stream_readable.js:406:5)
  at readableAddChunk (_stream_readable.js:168:9)
  at ReadStream.Readable.push (_stream_readable.js:130:10)
  at TTY.onread (net.js:528:21)

[jsbjair]

I’ve found the same issue, for a different error, related when method connect is called.

//Stack
events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: send -11
    at errnoException (/usr/local/owner/project/node_modules/subProject/node_modules/winston-syslog/node_modules/unix-dgram/lib/unix_dgram.js:18:11)
    at Socket.send (/usr/local/owner/project/node_modules/subProject/node_modules/winston-syslog/node_modules/unix-dgram/lib/unix_dgram.js:93:24)
    at /usr/local/owner/project/node_modules/subProject/node_modules/winston-syslog/lib/winston-syslog.js:191:21
    at Syslog.connect (/usr/local/owner/project/node_modules/subProject/node_modules/winston-syslog/lib/winston-syslog.js:253:9)
    at Syslog.log (/usr/local/owner/project/node_modules/subProject/node_modules/winston-syslog/lib/winston-syslog.js:157:8)
    at transportLog (/usr/local/owner/project/node_modules/subProject/node_modules/winston/lib/winston/logger.js:228:15)
    at /usr/local/owner/project/node_modules/subProject/node_modules/winston/node_modules/async/lib/async.js:157:13
    at _each (/usr/local/owner/project/node_modules/subProject/node_modules/winston/node_modules/async/lib/async.js:57:9)
    at Object.async.each (/usr/local/owner/project/node_modules/subProject/node_modules/winston/node_modules/async/lib/async.js:156:9)
    at Logger.log (/usr/local/owner/project/node_modules/subProject/node_modules/winston/lib/winston/logger.js:240:9)

unix-dgram code of connect():

  // FIXME defer error and callback to next tick?
  if (err < 0)
    this.emit('error', errnoException(err, 'send'));
  else if (err === 1)
    this.emit('congestion');
  else if (typeof callback === 'function')
    callback();

code:

  //
  // Create the appropriate socket type.
  //
  if (this.isDgram) {
    if (self.protocol.match(/^udp/)) {
      this.socket = new dgram.Socket(this.protocol);
    }
    else if (self.protocol === 'unix') {
      this.socket = require('unix-dgram').createSocket('unix_dgram');
    }
    else {
      return this._unixDgramConnect(callback);
    }

    return callback(null);//Here, callback is called as if no error occurred, but no events handlers has been attached to socket yet.
  }

when protocol is equal ‘unix’, the socket is created without events handlers attached, so, all errors events from socket is throw as an Unhandled ‘error’ event. But when protocol is defined as unix-dgram, a call to ._unixDgramConnect() is made, so events handlers is attached to the socket created.

[bnoordhuis]

Re: https://github.com/winstonjs/winston-syslog/issues/19#issuecomment-1137377288, I didn’t look into how winston-syslog uses unix-dgram but after a “congestion” event you should pause until the next “writable” event.

“congestion” is only emitted for connected sockets. For unconnected sockets you should just back off a bit and retry.

It sounds like there’s a bug in winston-syslog because that -9 error code is EBADF (bad file descriptor) and suggests it closed the socket while still using it.