UDP datagram sockets don't seem to close properly when on a cluster.Worker

[jcmoore]

Tested Mac OSX Mavericks in node.js 0.11.12 and 0.11.13 (hope that's recent enough).

Assertion will be thrown when doing the following:

https://gist.github.com/jcmoore/0ee16fe8fcfbe1a19f4c

My logs are as follows:

cluster internalMessage: online
sockets 0
sockets 1
cluster internalMessage: queryServer
cluster.queryServer: worker[86366, 1] (0.0.0.0:0:udp4:-1)
cluster internalMessage: undefined
sockets 2
cluster internalMessage: queryServer
cluster.queryServer: worker[86366, 1] (0.0.0.0:0:udp4:-1)
cluster.queryServer: CONFLICT! worker[86366, 1] (0.0.0.0:0:udp4:-1)

assert.js:98
  throw new assert.AssertionError({
        ^
AssertionError: false == true
    at SharedHandle.add (cluster.js:77:3)
    at queryServer (cluster.js:402:12)
    at Worker.onmessage (cluster.js:360:7)
    at ChildProcess.<anonymous> (cluster.js:611:8)
    at ChildProcess.<anonymous> (/Users/jmoore/Sites/toast/toast/sandbox/test.js:109:23)
    at ChildProcess.EventEmitter.emit (events.js:129:20)
    at handleMessage (child_process.js:323:10)
    at Pipe.channel.onread (child_process.js:351:11)

[greenboxal]

I have the same problem when using PM2 and ain2 to send UDP packets to syslog.
Calling socket.bind({ port: 0, exclusive: true }); seems to fix the problem as the worker doesn't try to share the handle with the master.

[greenboxal]

I was debugging the cluster module, when you close the socket the worker is not being removed from the SharedHandle list.
This could be fixed by sending the close message to the master. Doing this, an assertion is fired when the worker dies as the master try to remove the worker from the SharedHandle(at removeHandlesForWorker).

Also, changing the SharedHandle.add method to ignore if it worker is already on the list(maybe just for UDP sockets), would fix the issue.

In any case, I don't know which is the correct behaviour.

[sam-github]

@greenboxal

Doing this, an assertion is fired

I'm trying to fix this in:
#8642

[tjmehta]

+1

[anandkumarpatel]

+1

[tjmehta]

This problem seems to be occurring in with Node v0.12.2 on OSX Mavericks (and ubuntu 14.04)