cluster.on('message') not return worker

[Hamper]

• Version: 4.4.0, 5.9.0
• Platform: Linux test 4.4.4-calculate deps: update openssl to 1.0.1j #1 SMP PREEMPT Wed Mar 9 16:35:58 MSK 2016 x86_64 Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz GenuineIntel GNU/Linux
• Subsystem: cluster, documentation

In documentation:

Event: 'message'#
worker <cluster.Worker>
message <Object>
Emitted when any worker receives a message.

but real use is:

cluster.on('message', msg => { /* worker isn`t known */ })

[Fishrock123]

@Hamper Try: cluster.on('message', (msg, worker) => { })?

[Fishrock123]

It does looks like order of the arguments as told by the docs is incorrect though.

[Hamper]

'use strict'
const cluster = require('cluster')

if (cluster.isMaster) {
    cluster.on('message', (msg, wrk) => console.log(`msg=${msg}, wrk=${wrk}`))
    cluster.fork()
} else {
    cluster.worker.send('test')
    process.send('test2')
}

result:

msg=test, wrk=undefined
msg=test2, wrk=undefined

[mscdex]

The documentation agrees with master, but not 5.x/4.x.

[MylesBorins]

a doc fix PR should be made targeting both v5.x and v4.x-staging

edit: this will need to be 2 pr's

[mscdex]

Looks like the worker argument was added/fixed in 66f4586.

[jasnell]

@nodejs/documentation

[Cobraeti]

Hi,
Is it planed to be fixed in LTS version?
I just downloaded the last one (v4.4.4 from 05/05/2016) and it is still behaving as discribed in @Hamper 's first post...

[Knighton910]

In the top of your else statement try this process.on('message')

[Cobraeti]

Hi @lordKnighton ,
I already use process.on('message') as my worker emits that event in a sub-sub-sub-module and I don't want to pass the Cluster object to all intermediate module ^^
The problem is in the other way, when using the process.send() method (worker's syde).
As described by @Hamper , the cluster.on('message') method receives only a message parameter, so when using the following code:

var cluster = require('cluster');

if(cluster.isMaster) {
    cluster.on('message', function(worker, message) {
        console.log(`Worker ${worker.id} said "${message}"`);
        console.log(`Worker ${worker} said "${message}"`);
    }
    cluster.fork();
}
else {
    process.send('Hello World!!!!');
}

The result in console is:

Worker unknow said "unknow"
Worker Hello World!!!! said "unknow"

[Cobraeti]

I've just tested the same code within Node.js v6.1.0 and it works like a charm.
It seems that the change has been implemented in that version (don't know for v5.x).
Hopefully, my dependencies can now compile again (that was not the case whith v5.x a few weeks ago), so I would definitely switch to this better one.
I hope my comment will at least help to bring up the issue for those who can't switch version...

[cjihrig]

A fix for v4.x-staging is at #7297. I'm inclined to not fix v5.x, as it is EOL in a couple weeks.

[cjihrig]

Closed in 47f82cd.